practice w/ off cam flash and umbrella

[Elaine]

I received my umbrella and light stand in the mail today! This is only the third time I've really tried shooting/practicing/playing with off camera flash. I have a long cord from the camera to flash which means I must shoot with manual flash. I have not a clue what I'm doing! :huh:D
This is not meant to be anything pretty, just a hubby-won't-you-sit-down-and-let-me-point-this-umbrella-at-you kind of shot. I took this late at night in the living room and I'm sure you can tell I have some "fill" coming in on camera left from a lamp. I'm hoping that during the day, I will have nice fill coming in the sliding door and windows that are behind me and the umbrella will provide a bit more directional light and nice catchlights. (Does that make sense?) Can you tell from this if I have the umbrella in a good position or not?
I did try a few earlier in the day with my 7 yo son (my second time with off cam flash). What frustrated me was having to use ISO 800 at 2.8 and still only getting 1/13 of second. What was I doing wrong?
As I said, this shot was done in a very dark room at night, so I bumped up to ISO 1600, 2.8 (a bit shallow) and 1/25 sec. (Not very practical.) I think the flash was set to 1/128, shooting through the umbrella, not too far out of frame.

http://e-heasley.smugmug.com/photos/468458487_4mLee-XL.jpg

[Mike J]

Hi Elaine,

If you were really at 1/128 power, I would think that you were seriously underpowered and the flash was not actually contibuting all that much. I would think at shutter speeds of 1/13 or 1/25, those high ISOs, and wide-open lens settings, you were really exposing for the ambient light (what little there was) and getting very little from the flash?

I know I'm probably tell you stuff that you know, but this will also make sure I understand this so bear with me :D (someone correct me if my understanding is wrong) - my understanding is that the shutter speed is used to control the amount of ambient light and the aperature is used to control the amount of flash that reaches the sensor because the flash duration is so short.

When I got my setup three weeks ago, I started out at 1/125 at f/5.6 with the flash on full power. Caused serious blowouts but I just keep dialing the flash down until I got to 1/4 power which seemed about right according to the histogram. I sure there are better ways to do this but this worked for me.
YMMV. Good luck and keep practicing.

[Scott_Quier]

I received my umbrella and light stand in the mail today! This is only the third time I've really tried shooting/practicing/playing with off camera flash. I have a long cord from the camera to flash which means I must shoot with manual flash. I have not a clue what I'm doing! :huh:D
This is not meant to be anything pretty, just a hubby-won't-you-sit-down-and-let-me-point-this-umbrella-at-you kind of shot. I took this late at night in the living room and I'm sure you can tell I have some "fill" coming in on camera left from a lamp. I'm hoping that during the day, I will have nice fill coming in the sliding door and windows that are behind me and the umbrella will provide a bit more directional light and nice catchlights. (Does that make sense?) Can you tell from this if I have the umbrella in a good position or not?
I did try a few earlier in the day with my 7 yo son (my second time with off cam flash). What frustrated me was having to use ISO 800 at 2.8 and still only getting 1/13 of second. What was I doing wrong?
As I said, this shot was done in a very dark room at night, so I bumped up to ISO 1600, 2.8 (a bit shallow) and 1/25 sec. (Not very practical.) I think the flash was set to 1/128, shooting through the umbrella, not too far out of frame.


Off-camera flash in manual mode means you need to set your camera to manual mode as well. Here's what you do (and ignore the light meter in your camera!!!)

Position your strobe/brellie about 45 degrees off the camera-subject line, and up a bit above subject's eyes.
If you want fill - use a reflector on the other side of your subject to bounce some of the flash spill back onto your model.
Set camera (in manual mode) to ISO 100 (or 200), 1/200 (+/-), and f/5.6 - at these settings, you camera is going to try to tell you that your picture is going to be hugely under-exposed. But, you know things the camera doesn't - you are going to be supplying additional light it doesn't know about!:wink
Set flash to 1/4 power - it's a good place to start
Take a shot
Look at the picture (for blinkies) and the histogram - how's the exposure?
Make adjustments to the flash power and do it again.

As indicated by Mike J, the shutter speed is used to control the extent to which ambient light contributes to the exposure. At the above settings you will be getting, effectively, no contribution from ambient.

Edit: Actually, I sligthly mis-stated something above. When using flash INDOORS with Canon equipment, you want to put the camera in manual mode. Otherwise, the camera will meter the ambient light and set the camera to expose for that light level - usually meaning that the shutter speed will be 1/15 or some other ridiculous value. Outdoors is a whole other story and is outside the scope of the dicussion here.

[Trevlan]

Off-camera flash in manual mode means you need to set your camera to manual mode as well. Here's what you do (and ignore the light meter in your camera!!!)

Position your strobe/brellie about 45 degrees off the camera-subject line, and up a bit above subject's eyes.
If you want fill - use a reflector on the other side of your subject to bounce some of the flash spill back onto your model.
Set camera (in manual mode) to ISO 100 (or 200), 1/200 (+/-), and f/5.6 - at these settings, you camera is going to try to tell you that your picture is going to be hugely under-exposed. But, you know things the camera doesn't - you are going to be supplying additional light it doesn't know about!:wink
Set flash to 1/4 power - it's a good place to start
Take a shot
Look at the picture (for blinkies) and the histogram - how's the exposure?
Make adjustments to the flash power and do it again.As indicated by Mike J, the shutter speed is used to control the extent to which ambient light contributes to the exposure. At the above settings you will be getting, effectively, no contribution from ambient.

Edit: Actually, I sligthly mis-stated something above. When using flash INDOORS with Canon equipment, you want to put the camera in manual mode. Otherwise, the camera will meter the ambient light and set the camera to expose for that light level - usually meaning that the shutter speed will be 1/15 or some other ridiculous value. Outdoors is a whole other story and is outside the scope of the dicussion here.

This is put very well Scott. It's in terms that even I understand. Great little information. Thanks for this.

[Scott_Quier]

This is put very well Scott. It's in terms that even I understand. Great little information. Thanks for this.
It's in terms that I just barely understand! :confused:lol4

[Elaine]

Thanks, folks!

Just to clarify and provide more info on my meager attempt...my camera is always in manual mode. I don't remember the last time it wasn't! (So, yes, I came up with those crazy settings all by myself!) The room was Dark. The light seen here is definitely not ambient (except for the little bits spilling onto his right side). I took a shot without flash once and you couldn't really make out his face. That being said, I do believe I was thinking more along the lines of shooting for the flash being fill, which obviously isn't correct here. (Did I mention I'm clueless?!) It sounds like I had the umbrella set about right. Yippee!

Today I will try again with a reflector and new settings. I'm thinking during the day that the window may provide enough fill though, maybe?
I will also start with your suggested settings, Scott. Is the idea here to kinda shoehorn the flash into working with parameters set by the camera? I mean, consider sync speed and needed DOF and desired ISO...then adjust flash to fit? Is that where the suggested settings come from? Just trying to understand the why.

Thank you very much!

[Scott_Quier]

Thanks, folks!

Just to clarify and provide more info on my meager attempt...my camera is always in manual mode. I don't remember the last time it wasn't! (So, yes, I came up with those crazy settings all by myself!) The room was Dark. The light seen here is definitely not ambient (except for the little bits spilling onto his right side). I took a shot without flash once and you couldn't really make out his face. That being said, I do believe I was thinking more along the lines of shooting for the flash being fill, which obviously isn't correct here. (Did I mention I'm clueless?!) It sounds like I had the umbrella set about right. Yippee!

Today I will try again with a reflector and new settings. I'm thinking during the day that the window may provide enough fill though, maybe?
I will also start with your suggested settings, Scott. Is the idea here to kinda shoehorn the flash into working with parameters set by the camera? I mean, consider sync speed and needed DOF and desired ISO...then adjust flash to fit? Is that where the suggested settings come from? Just trying to understand the why.

Thank you very much!
Everything except for the flash power is a rule of thumb I've developed for myself. Flash power - pick something and go from there.

With manual flash, I decided what I want from the camera. This drives the ISO and the aperture. I also want to control ALL the light that contributes to the exposure - this drives the shutter speed. I set aperture for the DOF I want and this, in combination with the ISO, drives the power needed from the flash.

For studio work, I don't like mixing ambient (from whatever source) with stobe - there's no telling if the light is the same color temperature. Different color temperatures is ALWAYS a problem unless you are going for that effect - and you usually aren't when doing portraits.

I would suggest, again, that you use your strobe and a white reflector for your main and fill. Close the curtains - the outside light will just confuse the issue for you.

[Swartzy]

Just to add a simple concept Elaine.....when you want to eliminate the ambient light/temps from your shots, simply set your camera at sync speed (say 1/250th) and stop down to the aperture you want...let's pretend f/8..then simply take a shot at your subject...no flash....see if you get a black frame...if so, then you're good to go. Once you've accomplished this it's a matter of flash power for your key, positioning the reflector/key for a touch of shadowing but nothing harsh....then it won't matter if the curtains are open or not...but maybe that lamp can go bye bye :rofl

[Elaine]

See, this was my plan all along...to post an odd shot with ridiculous settings so you guys would take pity on me and help me along! And it worked! :D Thank you!

Another question...how close should the flash be to the surface of the umbrella? I have the umbrella post attached about half-way up. Is that right?

[Trevlan]

One compound question I have, is about light and distance.

How far/close can you be away from your subject (Camera) and how far/close does the source light have to be from the subject?

[Elaine]

Okie dokie...I'm back with round 4 of my OCF w/ umbrella experiences!

This time, my settings were:
flash at 1/4 or 1/2
ISO 100
f/5
1/125
17-55 2.8 IS at 55mm on Canon 40D (no cropping on these shots)
I used a large piece of white foamcore board as a reflector on camera left. I wasn't sure it was doing much, so I took a shot without it. It was actually doing quite a bit!

I'm just not used to critiquing these sorts of shots, so I'm not sure what exactly to be looking for, or what to try and avoid next time. I welcome all tips!

http://e-heasley.smugmug.com/photos/468712952_RtSRN-XL.jpg

And this one's just for fun! Well, I guess they all are, actually! Anyway, he had to get a shot at the doc this morning, so I wanted a shot of him looking tough...with his bandaid...and cocoa smudges on his cheeks. Yes, I'm a mom!
And I wish I'd put him on the stool for this one so the chair back wasn't in the shot. Oh well!

http://e-heasley.smugmug.com/photos/468712724_pkGEp-XL.jpg

[Scott_Quier]

See, this was my plan all along...to post an odd shot with ridiculous settings so you guys would take pity on me and help me along! And it worked! :D Thank you!

Another question...how close should the flash be to the surface of the umbrella? I have the umbrella post attached about half-way up. Is that right?
The idea behind the umbrella is to make a larger light source. The closer the flash is to umby, the smaller the circle of light will be on it's surface. So, as long all the light from the flash is "captured" by the umbrella, the further they are from each other the better.
How far/close can you be away from your subject (Camera) and how far/close does the source light have to be from the subject?
The closer the light is to the subject the softer the shadows will be. By the same token, the closer the flash is to the subject the more rapidily the light will fall off and that can cause hot spots on the closer surfaces while those just a little further away are not sufficiently illuminated. So, it's a trade-off and only you, practicing with your equipment can decide what works.

[Swartzy]

One compound question I have, is about light and distance.

How far/close can you be away from your subject (Camera) and how far/close does the source light have to be from the subject?

Dependent on the lens one uses is the answer to the distance of camera to subject. If you want to shoot a portrait with a 400 mm (I've done so), you'll be quite aways out. The lighting again is similar but the considerations are: The softness of the light, the envelope of the light, and the power of the light. If you have enough power or say using a modifier to harness the light, the lightsource can be far away as well but with the trade off of a harsher look. This can also be achieved using your flashhead, setting the zoom to say 100mm, therefore you, camera and lightsource in this scenario are across the room.

Hopefully not to confuse the issue, remember this important rule. The closer the light, the softer, the farther the light, the harsher. Where your camera is makes no difference in that regard.

[Trevlan]

Okie dokie...I'm back with round 4 of my OCF w/ umbrella experiences!

This time, my settings were:
flash at 1/4 or 1/2
ISO 100
f/5
1/125
17-55 2.8 IS at 55mm on Canon 40D (no cropping on these shots)
I used a large piece of white foamcore board as a reflector on camera left. I wasn't sure it was doing much, so I took a shot without it. It was actually doing quite a bit!

I'm just not used to critiquing these sorts of shots, so I'm not sure what exactly to be looking for, or what to try and avoid next time. I welcome all tips!

http://e-heasley.smugmug.com/photos/468712952_RtSRN-XL.jpg

And this one's just for fun! Well, I guess they all are, actually! Anyway, he had to get a shot at the doc this morning, so I wanted a shot of him looking tough...with his bandaid...and cocoa smudges on his cheeks. Yes, I'm a mom!
And I wish I'd put him on the stool for this one so the chair back wasn't in the shot. Oh well!

http://e-heasley.smugmug.com/photos/468712724_pkGEp-XL.jpg

I didn't it was you until I saw this pic of your boy. Your daily galleries are amazing. I'm in no place to offer any advice to you. :bow

[Elaine]

I didn't it was you until I saw this pic of your boy. Your daily galleries are amazing. I'm in no place to offer any advice to you. :bow

{Where is that blushing smiley?!}

Uhh...thank you very much for the kind words.

Now...back to reality! You take pictures, don't you? (And awesome SPs!) So, you are in the place to offer advice. :wink

I've obviously got a ton to learn! :ear

[divamum]

:lurk

Nothing much to add, but following this thread with great interest.... :D

<TABLE cellSpacing=0 cellPadding=4 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by Trevlan
One compound question I have, is about light and distance.

How far/close can you be away from your subject (Camera) and how far/close does the source light have to be from the subject?

</TD></TR></TBODY></TABLE>

Just been reading up on the Inverse Square Law which isn't the entire answer, but I think is related to what you're asking, I think. As I understand it from one batch of reading (disclaimer: NOT GOOD WITH NUMBERS so I fully accept I may be completely wrong), one of the results of all those numbers is that the difference in light between an object close to the source and one, say, 3 ft away is going to be more significant than the difference in light between an object 3ft away and one 6 ft away. Or in other words, if you only have one light and want to minimise the background, keep the light source closer to the subject and get the background further away; if you want bg and subject to be more evenly lit, move the subject further back from the source to start wtih ... even if the bg is just as far away, the ISL will mean there's less light loss between the different distances (although from this i also infer that you need more light power to start with to travel those extra distances.)

(Please read disclaimer again. SO not good with numbers. Back to lurking on this one :lurk)

[Trevlan]

Dependent on the lens one uses is the answer to the distance of camera to subject. If you want to shoot a portrait with a 400 mm (I've done so), you'll be quite aways out. The lighting again is similar but the considerations are: The softness of the light, the envelope of the light, and the power of the light. If you have enough power or say using a modifier to harness the light, the lightsource can be far away as well but with the trade off of a harsher look. This can also be achieved using your flashhead, setting the zoom to say 100mm, therefore you, camera and lightsource in this scenario are across the room.

Hopefully not to confuse the issue, remember this important rule. The closer the light, the softer, the farther the light, the harsher. Where your camera is makes no difference in that regard.

And this is becauses light travels indefinately at the same intensity.

If you want to get technical, I guess the GN number of the flash determines how powerful the light is and for what distance the flash can keep the light tight before it's spreads. If you were to put the flash 100 yards away, and take a picture of the light from the flash, you'll get the same brightness from the flash no matter what distance you are from it. The usable light is determined by how close the main light is to the subject. The further away, the wider the beam and more light spill. But it's still the same intesity.

So therefore; Closer, the light is tight, more light is reflected off the subject and it seems brighter. Further, that same light is spread more across more of the scene and it seems darker, when in essence it's the same brightness, just spread accross a larger area.

Does this make sense, or am I completely off?

[Swartzy]

And this is becauses light travels indefinately at the same intensity.

If you want to get technical, I guess the GN number of the flash determines how powerful the light is and for what distance the flash can keep the light tight before it's spreads. If you were to put the flash 100 yards away, and take a picture of the light from the flash, you'll get the same brightness from the flash no matter what distance you are from it. The usable light is determined by how close the main light is to the subject. The further away, the wider the beam and more light spill. But it's still the same intesity.

So therefore; Closer, the light is tight, more light is reflected off the subject and it seems brighter. Further, that same light is spread more across more of the scene and it seems darker, when in essence it's the same brightness, just spread accross a larger area.

Does this make sense, or am I completely off?

Hehe....Rocket science....love it! :roflYep, makes sense and am certain there are other variables that the math wizards could demonstrate with graphs and flowcharts. The basic equation though should be, "What does it mean when I want to achieve a particular photographic look"? In the end, that is all that's important.

[Trevlan]

{Where is that blushing smiley?!}

Uhh...thank you very much for the kind words.

Now...back to reality! You take pictures, don't you? (And awesome SPs!) So, you are in the place to offer advice. :wink

I've obviously got a ton to learn! :ear

I take awesome SPs!?! YAY! I'm not completely wasting my time with this photography stuff. LoL. Thanks Elaine.

I guess I'm star struck here. With you, Tippie, Kerry, basically everyone who isn't me. LoL. You guys are great. Keep up the inspirational work. May creativity never leave you.

Now back on topic! What would happen if you used a mirror to reflect the light instead of a piece of foam core? :scratch You know what I think could happen, I think you would amplify the distance your light will travel from your strobe. I have to test this!!!!!!!! Posting results tonight.

[Elaine]

To add to the discussion...

I enjoyed reading some of Zach Arias's info the other day, including this about umbrellas vs soft boxes:
http://www.zarias.com/?p=27

There are lots of other good posts with pics on his site as well.

[Elaine]

Anyone with anything to say about my recent pics?? Please? Good, bad, indifferent? :smo (That's me, being impatient!) :D

[Trevlan]

Anyone with anything to say about my recent pics?? Please? Good, bad, indifferent? :smo (That's me, being impatient!) :D

How far away was the boy from the background? Also, what did you use for fill light? (Left side of the face looks 3 - 4 stops darker to me.

The picture in black and white looks pretty hot on this monitor, was the light source closer this time? Or did you raise the power of the flash?

[Elaine]

How far away was the boy from the background? Also, what did you use for fill light? (Left side of the face looks 3 - 4 stops darker to me.

The picture in black and white looks pretty hot on this monitor, was the light source closer this time? Or did you raise the power of the flash?

He was sitting about 5 feet in front of the wall. No fill light, only the foamcore board as reflector about 1 foot away on camera left.

The b&w is quite contrasty, but I don't think it's totally blown. The brightest spot I can find on his arm is reading 223, 222, 221 and his temple is 242, 241, 241.

The umbrella (shoot through, not bounce) is sitting about 2 feet away from him on camera right. I don't think it was any closer for the b&w. At some point, I went from 1/4 to 1/2 on the flash, but I can't remember if that was between these shots (the b&w was actually shot first) or before both of them.

Should I move the reflector even closer, if possible? Is my umbrella a bit too high for him?

[Scott_Quier]

#1 of your son ... It all looks good except, maybe your aperture could have been 5.6 or a little smaller - it looks, maybe, just a little hot. The light falloff to the background is just about perfect. :thumb

#2 of your son ... This one is a touch hotter than the first - higher contrast. As a B&W I think it works very well. The lack of fill is very appropriate to the B&W as well (or, maybe the B&W is appropriate for the lighting on this photo). The only nit I see on this one is the lack of catchlights in the eyes - and that's a matter of taste.

Reflector on #1 looks just about perfect - again, the amount of fill is a matter of taste. The key light is in a good position - a bit more the camera left would have given a more "classic" loop lighting shadow from his nose - but that's a nit.

[Elaine]

#1 of your son ... It all looks good except, maybe your aperture could have been 5.6 or a little smaller - it looks, maybe, just a little hot. The light falloff to the background is just about perfect. :thumb

#2 of your son ... This one is a touch hotter than the first - higher contrast. As a B&W I think it works very well. The lack of fill is very appropriate to the B&W as well (or, maybe the B&W is appropriate for the lighting on this photo). The only nit I see on this one is the lack of catchlights in the eyes - and that's a matter of taste.

Reflector on #1 looks just about perfect - again, the amount of fill is a matter of taste. The key light is in a good position - a bit more the camera left would have given a more "classic" loop lighting shadow from his nose - but that's a nit.

Thank you! I feel like I'm at least heading towards the right track, thanks to your help, and others here!

So, stopping down the aperture helps control the amount of flash captured, right? It's such a mental shift to shoot at 5.6 or smaller. I rarely shoot over f/4 with natural light portraits. This is a whole 'nother story!

Yes, the lack of catchlights jumped out a me as well, but then I decided it kinda suited this particular shot. (Or, I'm embracing the goof since it's my son in the shot!)

[Scott_Quier]

Thank you! I feel like I'm at least heading towards the right track, thanks to your help, and others here!

So, stopping down the aperture helps control the amount of flash captured, right? It's such a mental shift to shoot at 5.6 or smaller. I rarely shoot over f/4 with natural light portraits. This is a whole 'nother story!

Yes, the lack of catchlights jumped out a me as well, but then I decided it kinda suited this particular shot. (Or, I'm embracing the goof since it's my son in the shot!)
Not only are you one the right track, but I think you are racing right along. I would think you should be quite pleased/proud of your progress!:thumb

Yes, the aperture controls the amount of light getting to the sensor. You've already got your settings such that you are not getting any ambient. Stopping down further will reduce the amount of flash getting there.

By way of example, these (http://www.dgrin.com/showthread.php?t=118048) and these (http://www.dgrin.com/showthread.php?t=118568) were all shot at about f/8 or f/9 - just to show you that, up to a point, it's not a bad thing to shoot with smaller apertures.

As for that catchlights - I think it's entirely appropriate for there not to be any in this photo. Trust your instincts - they've served you well in the past (I've spent a lot of time in your smugmug galleries!).

[jeffreaux2]

Okay Elaine.....lets forget the first set.....and move right on to the second.

Aside from the slight nits mentioned already you are making this look quite easy. Are you sure you havent done this before? (j/k!)

Seriously, they look great so far. A bit more experimentation and Ill bet you will be ready to teach me how to do this when I get my umbrella next week!

Are you up for it"?

[Trevlan]

To add to the discussion...

I enjoyed reading some of Zach Arias's info the other day, including this about umbrellas vs soft boxes:
http://www.zarias.com/?p=27

There are lots of other good posts with pics on his site as well.

In regards to this post, if anyone read it, the example pictures of the brolly box/umbrella, show the back of the umbrella with out the cover on it. When using the 'umbrella' function does it matter if the back is covered? Do you loose light? This would be nice and easy to switch between umbrella and shoot through functions on the fly. Can someone confirm this? I'm at work and can't test...

[Scott_Quier]

In regards to this post, if anyone read it, the example pictures of the brolly box/umbrella, show the back of the umbrella with out the cover on it. When using the 'umbrella' function does it matter if the back is covered? Do you loose light? This would be nice and easy to switch between umbrella and shoot through functions on the fly. Can someone confirm this? I'm at work and can't test...
The "back" of the brollie is there, when used, to prevent light spill - to better control where the light is going. As depicted in the link, light is bounced from the brollie forward. There's also the light that went through the brollie and will, eventually, bounce off a wall and back toward the subject. Depending on the distance this light travels (see "inverse-square law for more detail on that), it the light may be enough to impact on the exposure/lighting.

Which way you use a brollie is, naturally, completely up to the photography - one just has to be aware of the impacts on the resulting photograph of such decisions.

[Trevlan]

The "back" of the brollie is there, when used, to prevent light spill - to better control where the light is going. As depicted in the link, light is bounced from the brollie forward. There's also the light that went through the brollie and will, eventually, bounce off a wall and back toward the subject. Depending on the distance this light travels (see "inverse-square law for more detail on that), it the light may be enough to impact on the exposure/lighting.

Which way you use a brollie is, naturally, completely up to the photography - one just has to be aware of the impacts on the resulting photograph of such decisions.

I must have worded it wrong. My umbrella has a removable back. I don't care if the light spills out of the back of it. What I'm interested in knowing is, if I don't have the back, will we loose the intensity of the flash power because more light is escaping and not being shot back?

The idea is to be able to use the brolly side as well as the umbrella side on the fly and switch between both on the fly without having to replace/remove the Black backing of the umbrella. I'll have to post a picture of my rig...

[Elaine]

I must have worded it wrong. My umbrella has a removable back. I don't care if the light spills out of the back of it. What I'm interested in knowing is, if I don't have the back, will we loose the intensity of the flash power because more light is escaping and not being shot back?

The idea is to be able to use the brolly side as well as the umbrella side on the fly and switch between both on the fly without having to replace/remove the Black backing of the umbrella. I'll have to post a picture of my rig...

My umbrella also has a removable black back. I'm under the impression that using it will provide a stronger bounce back than not using it. Depending on the situation, this could be important or not. But I have not yet tested this.

[Elaine]

Okay Elaine.....lets forget the first set.....and move right on to the second.

Aside from the slight nits mentioned already you are making this look quite easy. Are you sure you havent done this before? (j/k!)

Seriously, they look great so far. A bit more experimentation and Ill bet you will be ready to teach me how to do this when I get my umbrella next week!

Are you up for it"?

Thanks a bunch, Jeff! I get another chance to try things out with my friend today, which should be fun. I seriously doubt you'll need any pointers from me. Thank you for the tips and encouragement.

[jeffreaux2]

Thanks a bunch, Jeff! I get another chance to try things out with my friend today, which should be fun. I seriously doubt you'll need any pointers from me. Thank you for the tips and encouragement.

I cant wait to see the results!

I have always enjoyed seeing your knack for composition and content in your photographs. You often include with the shots you share a comment about some technique or technical thing you are experimenting with but aren't quite comfortable with...yet it almost always appears to be a fluid part of your repetoire...and the taste, the style, the "something" of Elaine always is there.....and THAT is a treat Elaine!:thumb

[Scott_Quier]

I cant wait to see the results!

I have always enjoyed seeing your knack for composition and content in your photographs. You often include with the shots you share a comment about some technique or technical thing you are experimenting with but aren't quite comfortable with...yet it almost always appears to be a fluid part of your repetoire...and the taste, the style, the "something" of Elaine always is there.....and THAT is a treat Elaine!:thumb
Ummmm .... yeah! :agree

[NateW]

I must have worded it wrong. My umbrella has a removable back. I don't care if the light spills out of the back of it. What I'm interested in knowing is, if I don't have the back, will we loose the intensity of the flash power because more light is escaping and not being shot back?

The idea is to be able to use the brolly side as well as the umbrella side on the fly and switch between both on the fly without having to replace/remove the Black backing of the umbrella. I'll have to post a picture of my rig...

The light energy output by the flash will be the same in both cases, but where that energy goes to will differ.
I don't have a "brolly Box" setup, only a shoot-through/umbrella reflector, but I've not found myself switching around much at this point (pretty much stuck to the shoot-through).
Since the light energy per given area will decrease with the inverse square law, if you've got walls that don't mess with the colors, and an open umbrella back...
(ed: the following assumes the reflecting surface of the umbrella and the transmittance of the same surface is the same; I have no idea if this is true but it shouldn't _too_ far off. I think. Confidence is kinda low, but no way to check right now...)
Say you put the umbrella surface 3 feet from the subject and the (reflecting) back walls are 6 feet from the same surface.
Light from umbrella to subject direct is at whatever you want it at, call it "X".
Light from the reflecting back walls is at something much less. (I'm working this out here, and I've kinda shown my limits at the same time...)
1/4 of the energy gets to the reflecting walls. The walls will reflect something less than perfectly (say 1/2 power), which puts us at 1/8.
Then this has to travel 3x the distance (or 1/9th power of what came off the walls) making a total of 1/72nd the power from the umbrella directly.

Unless I've messed up the example (may have, I'm not claiming anything special!), does the added light of the back walls matter?

Of course, all of this hinges on the idea that the umbrella reflects the same as it transmits. I'm beginning to suspect that's not the case. Someone with a light meter (not me) wanna test it out? (meter the flash 3 feet from the umbrella surface on both sides and see what it comes out to?)

(Gotta run: Daddy Daughter Dance is coming soon and I have to get ready!)

[Trevlan]

Okay, so I did a little shoot, in the night, next to the Big Pun mural in the Bronx. At first I was a little skeptical on using the camera's sync speed with the flash as the main.

Here are a couple of the highlights.

#1
http://trevlan.smugmug.com/photos/470563021_22ZGN-L.jpg

#2
http://trevlan.smugmug.com/photos/470562432_cV3Qs-L.jpg

#3
http://trevlan.smugmug.com/photos/470562049_tq4PL-L.jpg

So here is what I learned from this. As many of the more experienced photographers here said. The shutter speed controls the ambient light contribution, and the aperture controls the flash contribution. The guide of 1/250th @ f /5.6 flash @ 1/4 power works well. All of these shots were shot at 1/200th of a second with the main at 1/4 power and the fill at 1/8th power.

I didn't think that the flash was going to be powerful enough to illuminate the scene and my subject and I was happy to be proven wrong. A three or even 4 light setup would have made this look like broad daylight. (I only had 1 main and 1 fill light.)

Problems I encountered:

I did what was recommended and shot, without the flash on to see if I got a black frame. The D40 has a flash sync of 1/500th of a second, and I figured that wouldn't be necessary. That's a stop darker than 1/250, and come to think about it, all that did was control the fall off point. I could have shot the entire session at 1/500th using my aperture to control the intensity of the light.

The only issue is with mixed light. The damn eyes are like light mirrors. So the catch lights look all crazy instead of pure white. But none of the ambient light is being recorded, so why are the showing up on the eyes as catch lights? Because light is reflected indefinitely at the same intensity.

So I could have chosen to gel the flash to correct the catch light problem. Or spend an extra 20 seconds in photoshop. I decided to do the photoshop route since I knew there weren't going to be that many photos. But I'm sure in a 500 frame shoot, every second will count and you'll need to gel the flash to save you that time.

Here are some of the indoor shots. Lights on or off, didn't make a difference. Your flash is more powerful than you think!

#4
http://trevlan.smugmug.com/photos/470566354_6tWNv-L.jpg

#5
http://trevlan.smugmug.com/photos/470566104_oDpFT-L.jpg

#6

http://trevlan.smugmug.com/photos/470542809_2oSjv-L.jpg

So to summarize, and thanks for starting this thread Elaine, set your camera at to your flash sync speed. Set the main at 1/4 power and aperture to f /5.6. If you need more/less light: Work the combination out with your flash power and aperture. Leave the shutter alone.

I hope this thread helps other people who don't understand flash photography. I don't totally understand it, but with the help of this thread, I was able to take satisfactory pictures. On the indoor shots, even with flash for fill, I would have been shooting like 1/60th or 1/30th. Out door probably like a 2 second exposure, to achieve the same exposure. I'd rather not deal with the blur. Thanks!

(Quick note on the main light. SB600 GN 90. The fill was the SB800 GN 120, would have loved to use it as the main light, but it was the commander and needed to stay on top of the camera. All the GN means is how far the light will go before it falls off.)

[Scott_Quier]

There's a couple of things here that need correcting ... so ....
So here is what I learned from this. As many of the more experienced photographers here said. The shutter speed controls the ambient light contribution, and the aperture controls the flash contribution. The guide of 1/250th @ f /5.6 flash @ 1/4 power works well. All of these shots were shot at 1/200th of a second with the main at 1/4 power and the fill at 1/8th power.
The "rule" is that you can't control the flash with the shutter - you can only use the combination of ISO and aperture. Once you have those set for the flash, the only thing left with which to adjust the contribution from ambient is the shutter speed.
I didn't think that the flash was going to be powerful enough to illuminate the scene and my subject and I was happy to be proven wrong. A three or even 4 light setup would have made this look like broad daylight. (I only had 1 main and 1 fill light.)
And, I think that would have made these photos less than they are. Sometimes, less is more:deal I think more light would have destroyed the very nice atmosphere you have going in your photos.
Problems I encountered:

I did what was recommended and shot, without the flash on to see if I got a black frame. The D40 has a flash sync of 1/500th of a second, and I figured that wouldn't be necessary. That's a stop darker than 1/250, and come to think about it, all that did was control the fall off point. I could have shot the entire session at 1/500th using my aperture to control the intensity of the light.
Not sure what "control the fall off point" means. The faster shutter speed would have limited, even more, the contribution of ambient light to the exposure. If you got a dark frame at 1/250, there was nothing to be gained by going to 1/500 - nothing lost either :D
The only issue is with mixed light. The damn eyes are like light mirrors. So the catch lights look all crazy instead of pure white. But none of the ambient light is being recorded, so why are the showing up on the eyes as catch lights? Because light is reflected indefinitely at the same intensity.
Not sure this is correct. Reflected light (and maybe specular highlights) obeys the inverse-square law, just like "projected" light. Reason: because none of the light we use is columnated (all photos on a parallel path - like a laser).
So I could have chosen to gel the flash to correct the catch light problem. Or spend an extra 20 seconds in photoshop. I decided to do the photoshop route since I knew there weren't going to be that many photos. But I'm sure in a 500 frame shoot, every second will count and you'll need to gel the flash to save you that time.
Gelling the flash(es) would have made the catchlight from the flash a color similar to those created by ambient sources - if you used an appropriately colored gel. :D
Here are some of the indoor shots. Lights on or off, didn't make a difference. Your flash is more powerful than you think!
Ambient light does make a difference - but not in the exposure. It's nice to have ambient light when it comes time to focus:D
So to summarize, and thanks for starting this thread Elaine, set your camera at to your flash sync speed. Set the main at 1/4 power and aperture to f /5.6. If you need more/less light: Work the combination out with your flash power and aperture. Leave the shutter alone.
If you open up the aperture too much, you will admit more ambient light to the exposure. The only question is whether or not that additional ambient makes a significant contribution to the exposure. See above for my re-statement of the "rule".
I hope this thread helps other people who don't understand flash photography. I don't totally understand it, but with the help of this thread, I was able to take satisfactory pictures. On the indoor shots, even with flash for fill, I would have been shooting like 1/60th or 1/30th. Out door probably like a 2 second exposure, to achieve the same exposure. I'd rather not deal with the blur. Thanks!
Yes you did. I quite liked them - FWIW
(Quick note on the main light. SB600 GN 90. The fill was the SB800 GN 120, would have loved to use it as the main light, but it was the commander and needed to stay on top of the camera. All the GN means is how far the light will go before it falls off.)
Nope - the GN is an expression of the power of the light - how much light you will have at a given distance from the light source. Light fall-off is consistant regardless of the GN - for all practical purposes it all obeys the inverse-square law (unless you are talking lasers :D). There is no distant point where the light falls off - only a point in the distace from which the reflected light is not powerful enough to make a significant contribution to the exposure.

Well ... Sorry for the thread hi-jack but there were so many details that needed addressing and, as it turne dout, this was a lot more than I had intended but "the devil is in the details."

[Trevlan]

Well ... Sorry for the thread hi-jack but there were so many details that needed addressing and, as it turne dout, this was a lot more than I had intended but "the devil is in the details."

Please Scott, this is no hijack. This is a discussion, you are far more experienced than I am. Anything you can contribute will only make us better photographers. Thanks for taking the time.:bow

Where is Eliane and her new photos with the flash as the main light? Doing a search now on the inverse square law.

[Elaine]

Please Scott, this is no hijack. This is a discussion, you are far more experienced than I am. Anything you can contribute will only make us better photographers. Thanks for taking the time.:bow

Where is Eliane and her new photos with the flash as the main light? Doing a search now on the inverse square law.

Let's just say I wasn't nearly as successful as you were with the shots you just shared! :clap:thumb Nice job!!

[Ed911]

Just to add a simple concept Elaine.....when you want to eliminate the ambient light/temps from your shots, simply set your camera at sync speed (say 1/250th) and stop down to the aperture you want...let's pretend f/8..then simply take a shot at your subject...no flash....see if you get a black frame...if so, then you're good to go. Once you've accomplished this it's a matter of flash power for your key, positioning the reflector/key for a touch of shadowing but nothing harsh....then it won't matter if the curtains are open or not...but maybe that lamp can go bye bye :rofl


What a good idea...never thought of doing that...and yet so simple. Thanks for sharing.

[Trevlan]

Let's just say I wasn't nearly as successful as you were with the shots you just shared! :clap:thumb Nice job!!

I find that hard to belive. Thanks for the compliment. Can't wait to see your shots.