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View Full Version : just got 70-200is2.8 think it is not sharp?


magicpic
Jan-09-2008, 01:53 PM
http://widgetr.smugmug.com/photos/241580782-L.jpg
1/250, 4.5, ISO 200, FL 110mm
http://widgetr.smugmug.com/photos/241582606-L.jpg
1/250,4.5,ISO299, FL 80mm

I put in jpeg...could someone look at photo and tell me if they are sharp..I just got the 70-200 is 2.8 OK I do feel that most photos should be sharp spending that much money please hope to hear..thanks janis

DavidTO
Jan-09-2008, 01:54 PM
You'll need to post the EXIF for us to give you any valuable input.

Congrats on the lens! :clap

magicpic
Jan-09-2008, 02:04 PM
how do I copy the exif off my site..thanks

I posted the exif under the photos

King of Canada
Jan-09-2008, 04:02 PM
I posted the exif under the photos

Looks plenty sharp to me. The first shot just looks a little underexposed, with the slowish shutter resulting in a softer image. The second one looks fine though.

ziggy53
Jan-09-2008, 04:58 PM
Both shots are in shade for the face and head although the second has some more direct light just below her head. Shade usually requires some USM because of reduced contrast. If you want, I could post-process and show you what I mean.

The first image is also slightly back-focused. The hairs on top of her head are sharp.

The second image is dead on and prime focus is on her left eye.

Remember that at close distances DOF will be pretty shallow so you need to put focus where you want it using individual focus dots.

magicpic
Jan-09-2008, 05:05 PM
Both shots are in shade for the face and head although the second has some more direct light just below her head. Shade usually requires some USM because of reduced contrast. If you want, I could post-process and show you what I mean.

The first image is also slightly back-focused. The hairs on top of her head are sharp.

The second image is dead on and prime focus is on her left eye.

Remember that at close distances DOF will be pretty shallow so you need to put focus where you want it using individual focus dots.

ok what do you mean by back-focused? what do you mean by USM? I am beginning to think that I have a focus problem? sounds good..thanks janis

DavidTO
Jan-09-2008, 05:09 PM
Back focused means it focuses behind (in back of) the intended focus point.

magicpic
Jan-09-2008, 05:21 PM
Back focused means it focuses behind (in back of) the intended focus point.
I was trying to focus on the eyes what is usm thanks

Moogle Pepper
Jan-09-2008, 05:23 PM
USM- Ultra Sonic Motor

Foochar
Jan-09-2008, 05:55 PM
I was trying to focus on the eyes what is usm thanks

Actually I think by USM Ziggy was referring to UnSharp Mask, one of the tools that is included with Photoshop, a way to increase the apparent sharpness by increases the edge contrast (a simplified explanation).

Are you sure you had the center focus point selected and on the eye in both of these shots? The second shot looks like it has great focus, the first shot, as Ziggy pointed out looks like it is back focused, that is that the focus appears to have landed on the hairs on the top of her head, or possibly the scrunchy in her hair. This could be caused by any number of things, and a data set of only two images does not give anyone a lot to base a judgement on. With the thin DOF inherent to any larger aperture (4.5 is still fairly large, wide open at 2.8 is even larger) it is quite possible to get the top scrunchy in focus and have the eyes be out of focus.

Rockporters
Jan-09-2008, 06:00 PM
If you continue to have problems, and you're sure what you are doing is right, try a different lens. I just had two 70-200mm f4 L IS lenses, and one was consistently soft, while the other was crystal clear using the exact same settings. (this wasn't just comparing a few shots, it was many!)

FWIW, I think that maybe it's not focusing where you think it is. In photo #1 the focus on her face is soft, but the turtleneck is looking pretty sharp. In the second photo, the face is soft again, but some of the hair looks pretty sharp.

Which camera are you using? The 40D by chance? If so, pay attention to the focus marks in the viewfinder when shooting. (sorry can't remember what the heck they're called) Just lining up the center point doesn't do the trick, you have to make sure the camera/lens are actually focusing there. My guess is that you may be overlooking that step.

BTW the girl is a cutie!

ziggy53
Jan-09-2008, 06:15 PM
ok what do you mean by back-focused? what do you mean by USM? I am beginning to think that I have a focus problem? sounds good..thanks janis

Your original:

http://widgetr.smugmug.com/photos/241582606-L.jpg

My take on the image:

http://ziggy53.smugmug.com/photos/241650547-L.jpg

This was after:

Midtone sharpening action, which includes Shadow-Highlight where I brought up the shadows to open the eyes.
2 doses of UnSharpMask -
Amount 4%, Radius 51 pixels, Threshold 0
... and
Amount 102%, Radius .2, Threshold 0
The eyes were selected seperately and extra USM applied as well as Levels to lighten the eyes.
Levels used to shift the entire image slightly brighter.
I also tried to reduce the scratch on the left side of her face.

The full sized image is at:

http://ziggy53.smugmug.com/photos/241650547-O.jpg

I will remove if you wish.

magicpic
Jan-09-2008, 06:38 PM
If you continue to have problems, and you're sure what you are doing is right, try a different lens. I just had two 70-200mm f4 L IS lenses, and one was consistently soft, while the other was crystal clear using the exact same settings. (this wasn't just comparing a few shots, it was many!)

FWIW, I think that maybe it's not focusing where you think it is. In photo #1 the focus on her face is soft, but the turtleneck is looking pretty sharp. In the second photo, the face is soft again, but some of the hair looks pretty sharp.

Which camera are you using? The 40D by chance? If so, pay attention to the focus marks in the viewfinder when shooting. (sorry can't remember what the heck they're called) Just lining up the center point doesn't do the trick, you have to make sure the camera/lens are actually focusing there. My guess is that you may be overlooking that step.

BTW the girl is a cutie!

I used a 30d and I use the center focus and then reposition but when I repostion I hold the shutter button halfway to keep the focus I shoot in maual...thanks janis

magicpic
Jan-09-2008, 06:39 PM
Your original:

http://widgetr.smugmug.com/photos/241582606-L.jpg

My take on the image:

http://ziggy53.smugmug.com/photos/241650547-L.jpg

This was after:

Midtone sharpening action, which includes Shadow-Highlight where I brought up the shadows to open the eyes.
2 doses of UnSharpMask -
Amount 4%, Radius 51 pixels, Threshold 0
... and
Amount 102%, Radius .2, Threshold 0
The eyes were selected seperately and extra USM applied as well as Levels to lighten the eyes.
Levels used to shift the entire image slightly brighter.
I also tried to reduce the scratch on the left side of her face.

The full sized image is at:

http://ziggy53.smugmug.com/photos/241650547-O.jpg

I will remove if you wish.
thanks alot I think I need to work on my focus issue

Rockporters
Jan-09-2008, 08:09 PM
I used a 30d and I use the center focus and then reposition but when I repostion I hold the shutter button halfway to keep the focus I shoot in maual...thanks janis

Hi Janis, Do you manually focus, or use auto focus? You might read up on using the AF Points, if you haven't already.

jdryan3
Jan-11-2008, 08:03 PM
I used a 30d and I use the center focus and then reposition but when I repostion I hold the shutter button halfway to keep the focus I shoot in maual...thanks janis

Actually if you are using the center point (or any point), achieve it with the shutter half-way down and then recompose while still holding down the shutter half-way....it will refocus. Doesn't matter if you have set a single focus or are using all of them.

What you want to do is use the center point (or whatever one you want), achieve focus pressing the shutter down half-way, RELEASE the button, recompose, then press the shutter all the way down (take the shot). If you continue to hold it down it will continually refocus.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Hopefully I won't confuse things here, but does the 30D have a Custom Function that allows you to assign the focus to another button (like the * AE Lock )? This separates the shutter release from the focusing function. A lens like the 70-200 f/2.8 IS is desired because it is highly sensitive to focusing.

Keeping that shutter button even slightly depressed, especially on a shallow DOF like f/2.8 or f/4 will cause the lens to refocus very quickly. On my 5D, the custom function is Cf4 - and it makes a huge difference in the number of keeper shots.

hgernhardtjr
Jan-11-2008, 08:24 PM
Actually if you are using the center point (or any point), achieve it with the shutter half-way down and then recompose while still holding down the shutter half-way....it will refocus. Doesn't matter if you have set a single focus or are using all of them.

Not so if you have it in One-Shot AF mode. I often use focus lock with my 30D (and it is described on page 79 of the 30D owner's manual) in conjunction with the * button to lock AE at the same time.

jdryan3
Jan-11-2008, 08:38 PM
Not so if you have it in One-Shot AF mode. I often use focus lock with my 30D (and it is described on page 79 of the 30D owner's manual) in conjunction with the * button to lock AE at the same time.

Agreed. But the OP didn't say she is using One Shot or focus lock. Based on her post (and it is limited) I was trying to point out that achieving focus and reframing with the shutter half-way depressed will typically, out of the box, cause the camera to continue to refocus. Sorry if I wasn't clearer. It may be technique - not the lens.

Rockporters
Jan-13-2008, 05:46 AM
Hi Janis, Any luck mastering focus with your 70-200 yet? Just wanted to see if you've made progress, and are enjoying your new lens!

Rob Candito
Jan-13-2008, 10:43 AM
I just purchased the same lens a month ago. I think the back focus is apparent in the first photo, because I have done the same thing. The second photo looks good to my eyes. This is really a great lens for ports., because you can stay out of the subjects face. I have a friend that uses his (lens) for alot of his wedding photos. He recommended this lenstomeso I spent the big $$ to own this fine lens.

Antonio Correia
Jan-13-2008, 01:03 PM
I use this lens on a 20D with the center point and, for portrait in One Shot, for sports in the AI Focus mode.
I think - and I read - that focusing and recomposing is not a good way to work.
This procedure should only be used with wide angles or/and small apertures.
As a matter of fact, when we focus one point and then we recompose we may vary the distance camera target and this may be responsible for pictures out of focus.
Please: Go to the DOF calculator (http://www.dofmaster.com/doftable.html) and watch the DOF for this lens at f/4 and f/5.6 regarding the distance of your shot.
You will see that this difference is very shallow.
I made a screen shot and marked with dots and lines the important numbers in this case.
The gap is important. So important that you may go out of it.
You focus the eyes but a little movement put the focus in the hair.

I think it is better to focus with a large view having a nice focus than and a un-focused picture with a nice crop.

I hope I made myself understand.
:D

I am sorry but I don't know :dunno how to show this table in large or with a link. Anyway, the link is above.
Please, have a look (http://www.dgrin.com/showthread.php?t=36284&page=34)

Antonio Correia
Jan-14-2008, 12:43 PM
Here is a link about this focus and recompose method (http://visual-vacations.com/Photography/focus-recompose_sucks.htm)
And another (http://www.bobatkins.com/photography/technical/focus_recompose.html) one.

As I was driving today I could remember this thread and I thought that I gave you a poor answer.
My excuses for that. :bow
I post the links which are important for us to a better understanding of this problem.
:D
I just googled focus and recompose (http://www.google.com/search?q=focus+and+recompose&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a) Very easy !:D
:thumb

magicpic
Jan-15-2008, 11:24 AM
Here is a link about this focus and recompose method (http://visual-vacations.com/Photography/focus-recompose_sucks.htm)
And another (http://www.bobatkins.com/photography/technical/focus_recompose.html) one.

As I was driving today I could remember this thread and I thought that I gave you a poor answer.
My excuses for that. :bow
I post the links which are important for us to a better understanding of this problem.
:D
I just googled focus and recompose (http://www.google.com/search?q=focus+and+recompose&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a) Very easy !:D
:thumb

I am going to try to change the custom function on my 30d and see if it makes a difference, yes what I have been doing is using the center af and then recomposing so I am going to read the above and try this other...janis

eyusuf
Jan-23-2008, 06:11 AM
any new development on this subject? i'm really curios as to how this (expensive) lens performs out of the box.

Antonio Correia
Jan-23-2008, 09:07 AM
Shots with this lens (http://www.dgrin.com/showthread.php?t=36284). :clap:thumb