Topic: CTO and Green gels (Read 10344 times)

dwdallam · « **on:** May 30, 2008, 04:22:10 am »

What two gels should I make sure I have for warm and cool florescent and what is a good middle of the road tungsten gel or two?

If you can point me to B&H for any specific manufacture, such as Rosco etc, that would be appreciated.

I just want to make sure I can gel my strobes and set my tungsten setting for WB and get a blue tint to everything NOT hit by the strobes, including the sky. Same for the greens, but I know there are many varieties of FL bulbs now. That's why I chose warm and cool, which are the most used. Alternately, whatever green is closest to the preset FL setting in the Canon cameras would be fine.

Thanks

DarkPenguin · « **Reply #1 on:** May 30, 2008, 03:01:42 pm »

You might consider strobist.com or the flickr strobist group. Great strobe resource. (Mostly small strobe, however.)

Sheldon N · « **Reply #2 on:** May 30, 2008, 08:59:31 pm »

Go to the Lee filter website, and submit a request for their gel sample pack - it's free. You might have to hunt around to find the link, maybe try google. Mine took about 2 weeks to show up in the mail, got it around a month ago. It has about 200 individual gels of every imaginable color (including CTO and FLD in varying strengths).

To attach it to your flash, get one of the Honl Photo "Speed Straps" for velcro attachments. It's nice because it doesn't require that you stick any adhesives on your flash. You can also pick up a grid from them as well, a really handy and well made accessory for a shoe mount flash.

Then, just stop by a craft store and get some stick on adhesive velcro, cut a couple really thin strips to adhere to the edges of the individual flash gels. They work perfectly on a 550EX or 580EX II with the Honl speed strap.

If you need photos of my setup, shoot me a PM with your email address and I can send you some.

dwdallam · « **Reply #3 on:** May 30, 2008, 09:21:33 pm »

Quote

Go to the Lee filter website, and submit a request for their gel sample pack - it's free. You might have to hunt around to find the link, maybe try google. Mine took about 2 weeks to show up in the mail, got it around a month ago. It has about 200 individual gels of every imaginable color (including CTO and FLD in varying strengths).

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Well, I don't need every color. All I want is to gel for florescent and tungsten, and only the most widely used florescent, which is warm and cool. I have two CTOs picked out, which are straw and 1/2 CTO. I will probably pick up 1/4 and full CTO.

So you can see my reason for the specific request.

Sheldon N · « **Reply #4 on:** May 30, 2008, 11:45:42 pm »

Quote

Well, I don't need every color. All I want is to gel for florescent and tungsten, and only the most widely used florescent, which is warm and cool. I have two CTOs picked out, which are straw and 1/2 CTO. I will probably pick up 1/4 and full CTO.
So you can see my reason for the specific request.
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I guess you could throw away the other ones, if you didn't want to use them. They are free, after all.

I just pulled out the CTO (1/4, 1/2, 3/4 and full) and Fluorescent gels (1/2 and full) along with a red and blue for effects, then stuffed the rest in a closet.

I suppose if you wanted to buy sheets of just the CTO and fluorescent, you could order them directly from Lee for $20-30 total. But you might want to get the free swatchbook so you know what specific color number to specify in your order. You can get it at...

[a href=\"http://www.leefilters.com/lighting/contact/]http://www.leefilters.com/lighting/contact/[/url]

dwdallam · « **Reply #5 on:** May 31, 2008, 12:52:54 am »

Quote

I guess you could throw away the other ones, if you didn't want to use them. They are free, after all.

I just pulled out the CTO (1/4, 1/2, 3/4 and full) and Fluorescent gels (1/2 and full) along with a red and blue for effects, then stuffed the rest in a closet.

I suppose if you wanted to buy sheets of just the CTO and fluorescent, you could order them directly from Lee for $20-30 total. But you might want to get the free swatchbook so you know what specific color number to specify in your order. You can get it at...

http://www.leefilters.com/lighting/contact/
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OK that is a sound suggestion, for sure. I'll get it. Today I think I figured it out anyway. There are many variations, such as "straw" to CTO. Same for fluorescents too I guess. So I'll just get 1/4, 1/2, 3/4, and full of each color, except for the variations. For the variations on the original CTO and Florescent gels, I'll just pick what I think I will most use. The only real problem I had with getting the swatch--even if it is free--is that it has ONE of each gel. I'd like to have a sheet of each that I need. I think they are about 6 bucks each for a 20x30 sheet, something like that.

Hank · « **Reply #6 on:** May 31, 2008, 01:13:12 am »

I don't know what the numbers are, but back in the days of film we went through a lot and bought rolls of the stuff. At that time their own names were Grass Green and Straw, and thoey were "close enough" in most settings. We still have partial rolls and they work great. Haven't checked any of the online listings for Rosco products, but if they reference a name in addition to a number, those two should help you sort and choose.

dwdallam · « **Reply #7 on:** June 05, 2008, 07:13:18 am »

Quote

I don't know what the numbers are, but back in the days of film we went through a lot and bought rolls of the stuff. At that time their own names were Grass Green and Straw, and thoey were "close enough" in most settings. We still have partial rolls and they work great. Haven't checked any of the online listings for Rosco products, but if they reference a name in addition to a number, those two should help you sort and choose.
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Thanks Hank. I think they come in like 1/4, 1/2, 3/4, full for both green and CTO. I'll just buy a sheet of each.

timhurst · « **Reply #8 on:** June 05, 2008, 07:36:44 am »

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Thanks Hank. I think they come in like 1/4, 1/2, 3/4, full for both green and CTO. I'll just buy a sheet of each.
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Don't bother with the extortionately priced Lee stuff, find a theatre/stage lighting supplies store. They should sell by the metre (will last you years) and will be orders of magnitude cheaper than any camera shop.

snickgrr · « **Reply #9 on:** June 16, 2008, 06:26:32 pm »

Dwdallam,

Don't know where in NorCal you're located but if you're anywhere near SF, take a trip over to JCX and talk to Janet, the owner. They are an "expendibles" shop and sells everything surrounding your question...and more. I've been doing business with her since she opened her shop. She'll fix you up..or call her up and order from her.
There are links to all the expendibles manufacturers on her site.

http://www.jcxex.com/

Kirk Gittings · « **Reply #10 on:** June 16, 2008, 11:56:00 pm »

It would help to know what you are shooting. Mixed light architectural interiors with a strobe fill have a different approach than location portraits.

Ken Bennett · « **Reply #11 on:** June 18, 2008, 05:41:23 pm »

I think Rosco still sells a combo pack of green and CTO filters. Check this:

http://www.bhphotovideo.com/c/product/4523...ection_Kit.html

laughfta · « **Reply #12 on:** June 18, 2008, 08:06:13 pm »

I find it effective to layer the full and 1/2 cto gel so the ambient light is blue, but the area hit by the flash is additionally warmed by the 1/2 cto. (neutralized by the full cto) I bought a larger pack of the more commonly used gels which I can cut to size, and I also use the little sample gels from Tiffen. You can get Rosco sample packs from B&H for a penny with an order.

I was just practicing this technique last week, due to buzz from the Strobist site.

dwdallam · « **Reply #13 on:** June 23, 2008, 05:51:55 am »

Quote

I find it effective to layer the full and 1/2 cto gel so the ambient light is blue, but the area hit by the flash is additionally warmed by the 1/2 cto. (neutralized by the full cto) I bought a larger pack of the more commonly used gels which I can cut to size, and I also use the little sample gels from Tiffen. You can get Rosco sample packs from B&H for a penny with an order.

I was just practicing this technique last week, due to buzz from the Strobist site.
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That's nice indeed. We can get the same effect using layers though, through ACR and the WB option. I'm thinking this may be a dated approach to WB manipulation these days, unless, of course, one is shooting JPGs. But they can still be opened in ACR now also.

Last week I was in San Francisco and shot two models using dialed in WB in camera to get a similar affect. Then just used layers. You know we play with the WB anyway for both affect and accuracy, when needed.

So now I'm wondering why even bother with correction gels? The answer, I assume, would be when you want a certain affect and you don't want to play with the WB for speed in post production.

laughfta · « **Reply #14 on:** June 24, 2008, 03:35:19 pm »

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So now I'm wondering why even bother with correction gels? The answer, I assume, would be when you want a certain affect and you don't want to play with the WB for speed in post production.
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Well, I agree it's almost the same effect, and usually close enough. Its kind of like adding fake reflections to an image, though, or a drop shadow that may not quite ring true. If this is a lighting effect you are going for, I think it's much easier to gel the light and then tweak the WB in ACR than to create the light temperature separation in PS with layers. If one is trying to correct a mixed lighting situation (or create one) I think gelling is going to be much easier and one will have better results than PP.

dwdallam · « **Reply #15 on:** June 25, 2008, 04:05:15 am »

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Well, I agree it's almost the same effect, and usually close enough. Its kind of like adding fake reflections to an image, though, or a drop shadow that may not quite ring true. If this is a lighting effect you are going for, I think it's much easier to gel the light and then tweak the WB in ACR than to create the light temperature separation in PS with layers. If one is trying to correct a mixed lighting situation (or create one) I think gelling is going to be much easier and one will have better results than PP.
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From what I've read, WB adjustment in ACR is absolutely no different than doing it in camera. But you probably mean compositing may result in an unnatural effect? If so, I would guess that it would be in the areas directly around the subject, a halo effect. It would be nice to see a comparison.

laughfta · « **Reply #16 on:** June 25, 2008, 10:57:44 am »

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From what I've read, WB adjustment in ACR is absolutely no different than doing it in camera. But you probably mean compositing may result in an unnatural effect? If so, I would guess that it would be in the areas directly around the subject, a halo effect. It would be nice to see a comparison.
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Yes, that's what I mean. I've done a little experimenting and found that though I could easily change the light color with a hue/sat adjustment layer, I was effecting the background color as well within that halo. Not very noticeably, but absolutely there if you are looking for it. OTOH, sometimes the unnatural effect may be just what one wants, so I guess this is just another tool to use when needed. I am still referring to mixed lighting situations here, of course.

dwdallam · « **Reply #17 on:** June 27, 2008, 01:58:22 am »

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Yes, that's what I mean. I've done a little experimenting and found that though I could easily change the light color with a hue/sat adjustment layer, I was effecting the background color as well within that halo. Not very noticeably, but absolutely there if you are looking for it. OTOH, sometimes the unnatural effect may be just what one wants, so I guess this is just another tool to use when needed. I am still referring to mixed lighting situations here, of course.
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Ah I see what you mean. I had something a little different in mind.

What I do is open the RAW file and adjust either the subject or background for the WB I want. Open that file in PS. Go back and open the same file and adjust the WB for the other object, either the background or subject. Then open that file in PS. Now I have two files opened in PS. Both are exactly what I want: one with the background WB adjusted and one with the subject WB adjusted.

Now I copy one over to the other and have two layers total. I then use Mask (hide/reveal all) and use the mask to reveal the subject through the background.

So that is what I meant by natural results. Try it and see. That will be interesting to see. The whole effect takes me about 3 minutes or less.

Jonathan Wienke · « **Reply #18 on:** July 04, 2008, 09:20:55 am »

If you want to match any ambient light to your flash, do this:

1. Shoot a WB reference (WhiBal, Color CHecker, etc) RAW, lit only by flash.

2. Shoot a RAW of the same WB reference with the same camera lit only with the ambient you want to match.

3. Open the flash-only RAW and click-WB on the WB reference. Make a note of the WB settings you get.

4. Open the ambient RAW and process it with the WB settings from the flash RAW.

5. In Photoshop, use the color sampler tool to sample the resulting WB reference color of the ambient RAW.

6. Change the L value of the sampled color to 90, but do not alter the A or B values.

7. Fill a PS document with the resulting color, and print on transparency stock.

You now have a custom flash gel that will exactly match your flash to the ambient light. Repeat as necessary for as many types of ambient lighting you shoot in--incandescent, fluorescent, mercury vapor, sodium vapor...

Author Topic: CTO and Green gels (Read 10344 times)

DarkPenguin