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View Full Version : Praise to CTO


Nikolai
May-05-2008, 09:58 AM
After reading Joe McNally (http://www.amazon.com/Moment-Clicks-Photography-secrets-shooters/dp/0321544080/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1210005553&sr=8-1)'s wonderful book I have seriously reconsidered the way I use my flash, at least as a fill. Basically, now the gel filter is one of my best friends, and most popular of them is the "quarter CTO". For starters, CTO stands for "Color Temperature Orange", and they also can be of different level of intensity.
Apart from purely studio work I tend to shoot most of my portraits during sunset time or with the tungsten ambient light, hence my CTO gels never leave my location flash units. I'm using Rosco Swatch (http://www.bhphotovideo.com/c/product/45189-REG/Rosco_950SBLUX0103_Roscolux_Swatchbook.html) ones for Sunpaks (555) and Phoxle (http://www.phoxle.com/)'s for my 580EXII.
Once I started do it (just a couple month ago for sunpacks and a month for speedlite) I noticed a huge improvement in the overall color matching.
It sounds complicated, but once you do it a couple of times, you'll never go back to a bare flash.:deal
Highly recommended! :thumb

pathfinder
May-05-2008, 03:39 PM
:agree

Travis
May-05-2008, 05:01 PM
I'm onboard with CTO also! Joe's book was also one of the few that actually lived up to the hype.

Scott_Quier
May-06-2008, 05:06 AM
Been doing this a while, especially in wedding reception venues.

Something else to think about: I've since read that sometimes the CTO is a bit too orange. Another alternative is the CTS (straw). It is less orange, more yellow and can, sometimes, better match tungsten and/or early evening sunlight.

The strobist has been blogging about gelling flashes for the last little bit. Here's his take on CTO (link (http://strobist.blogspot.com/2008/05/lighting-102-62-gelling-for-tungsten.html)).

All this is to say that, FWIW, I completely agree with you Nik - gels are cool.:thumb :ivar

jeffreaux2
May-06-2008, 09:27 AM
:D Ditto pretty much everything so far. Most of my portrait work is taken in outdoor shady conditions where I use CTB(blue) gels to match the blue cast in shade. This is the area where I began my foray into flash gels. I have used the LEE filters for this, but am currently using Phoxles. I have only begun experimenting indoors with gels, but am pleased so far with the results.

I also have in my possesion, a set of the new "Sticky-Filters". They are much like the Phoxles, but contain a little different color set which includes options for flourecents. I haven't tried them yet. I first had to trim them down to fit inside the diffuser that I use on my speedlight as they are much larger than the Phoxles.

....and like Scott said...all this to say that not only do I agree, but that anyone who is not taking advantage of this technology in their own photography is....well...missing out!!:D

Nikolai
May-06-2008, 09:44 AM
This led me to thinking... How cool would it be to have a portable non-prohibitevly-expenisve device similar to a lightmeter that would meter the light color/temperature and tell you the value in K, even if approximate.:scratch

Then if you have your gel set you can immediately pick up the most suitable one. Currently it's a lot of guess work, although I understand that we all can figure out the ballpark...

Or maybe an advanced lightmeter that can read both? Or maybe have it built into camera body? Like, you do custom WB, but in addition to setting the temperature it could *read* the temperature?

I mean, even now one can obviously do several WB test shots of the gray target with custom WBs set to different K values and check the RGB histogram until it's as close to neutral as possible. This process should not take longer than a few minutes, especially if you start with a close enough K value. You can probably even use WB bracketing to get several test exposures quickly.

However, it's definitely a hassle. A dedicated color meter would be much faster/easier to use...:rolleyes

EDIT: googled it.. Such devices do exist (link to B&H (http://www.bhphotovideo.com/c/shop/904/Color+Temperature.html/atl/Brand_Gossen~Price_+1299.95+%3C=+50000/sortDrop/Price:+Low+to+High)), but the price.. Ouch..

SloYerRoll
May-06-2008, 09:46 AM
Or you could just practice to the point of not needing this at all and jsut balance light to taste:dunno

DavidTO
May-06-2008, 09:51 AM
Or you could just practice to the point of not needing this at all and jsut balance light to taste:dunno


But then he wouldn't be an engineer. :deal

Thanks for the links, Nik!

SloYerRoll
May-06-2008, 09:53 AM
But then he wouldn't be an engineer. :deal

Thanks for the links, Nik!True :D

Nikolai
May-06-2008, 10:01 AM
But then he wouldn't be an engineer. :deal
Yup! :rofl

Thanks for the links, Nik!
My pleasure. And that's the cheapest one. A better (IMHO) KM version is twice+ as much. :huh

ChrisP6
May-06-2008, 11:09 AM
This led me to thinking... How cool would it be to have a portable non-prohibitevly-expenisve device similar to a lightmeter that would meter the light color/temperature and tell you the value in K, even if approximate.:scratch

Or maybe an advanced lightmeter that can read both? Or maybe have it built into camera body? Like, you do custom WB, but in addition to setting the temperature it could *read* the temperature?

Nikolai -- You're absolutely right that it would be cool to have an inexpensive, portable color temp meter, and I think you're also on the right track trying to leverage the camera to do it. I asked the Nikon rep at PMA why their DSLR's didn't tell you what they sensed as the color temperature when you use them to do a custom white balance, and he said "of course they do that." We tried it, and of course they didn't. So, he said he thought it was a great idea, and that I could feel some satisfaction when they added the feature in the near future. I hope Canon got the message too, because that's what I shoot with :D

In the mean-time, the suggestion of using the RGB histogram and a target is a great one. I do this with the Phoxle SpectraSnap quite often, and find that it works well. Here's a quick set of measurements comparing the SpectraSnap/1DMkIII approach to the Gretag Macbeth EyeOne Pro spectrophotometer:

Tungsten Light -- SpectraSnap Histogram: 2700K, Spectrophotometer: 2727K
Fluorescent Light -- SpectraSnap Histogram: 5200K, Spectrophotometer: 5454K
North Window -- SpectraSnap Histogram: 7300K, Spectrophotometer: 7519K

Chris

Nikolai
May-06-2008, 01:41 PM
Nikolai -- You're absolutely right that it would be cool to have an inexpensive, portable color temp meter, and I think you're also on the right track trying to leverage the camera to do it. I asked the Nikon rep at PMA why their DSLR's didn't tell you what they sensed as the color temperature when you use them to do a custom white balance, and he said "of course they do that." We tried it, and of course they didn't. So, he said he thought it was a great idea, and that I could feel some satisfaction when they added the feature in the near future. I hope Canon got the message too, because that's what I shoot with :D

In the mean-time, the suggestion of using the RGB histogram and a target is a great one. I do this with the Phoxle SpectraSnap quite often, and find that it works well. Here's a quick set of measurements comparing the SpectraSnap/1DMkIII approach to the Gretag Macbeth EyeOne Pro spectrophotometer:

Tungsten Light -- SpectraSnap Histogram: 2700K, Spectrophotometer: 2727K
Fluorescent Light -- SpectraSnap Histogram: 5200K, Spectrophotometer: 5454K
North Window -- SpectraSnap Histogram: 7300K, Spectrophotometer: 7519K

Chris

Chris,
thank you very much for the info! :thumb
I'm glad you think that my approach is doable! :clap
At least we get someting to work on a dime and in a minute rather than shelling out several K$ to get and instant K readout..:wink