# Rear Gelatin Filter Questions



## mackguyver (Feb 11, 2015)

With a 11-24 f/4 on pre-order, I was thinking about getting some gelatin film(s) for the rear holder. If I remember, the holder on the existing lenses (14L, 8-15L, 17-40L, etc.) are all the same size. Can anyone confirm? If so, then it's probably pretty safe to _assume_ Canon will stick with the same size. Also, does anyone know the approximate dimensions of the gelatin that fits? I thought Canon had a template in the manual or on a sheet of paper, but I can't seem to find that online - maybe it was from another manufacturer.


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## Marsu42 (Feb 11, 2015)

mackguyver said:


> If I remember, the holder on the existing lenses (14L, 8-15L, 17-40L, etc.) are all the same size.



I only have the 17-40L, but if it helps I could find a yard stick and give you the measurement if you cannot find the sizes online.


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## mackguyver (Feb 11, 2015)

Thanks, Marsu - and measurements would be nice if you happen to have a moment. I'm sure Fotodiox will eventually come out with an adapter, but I'm guessing that could be several months or more.


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## Deleted member 91053 (Feb 11, 2015)

I believe that you are supposed to cut them out yourself from larger sheets. For reference the guidelines on my 17-40 are 31mm square, hope this is of help.


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## Jack Douglas (Feb 11, 2015)

mackguyver, please keep us posted on both the filters and the lens when it arrives. I'm sure you'll be motivated to. 

Jack


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## mackguyver (Feb 11, 2015)

johnf3f said:


> I believe that you are supposed to cut them out yourself from larger sheets. For reference the guidelines on my 17-40 are 31mm square, hope this is of help.


John, that's correct and I wanted to make sure I ordered large enough sheets. Thanks for the measurement!



Jack Douglas said:


> mackguyver, please keep us posted on both the filters and the lens when it arrives. I'm sure you'll be motivated to.


Jack, I will definitely do that. There are a number of gelatin type sheets out there - trying to narrow them down and decide which density or densities to try. I found some reasonably cheap C-PL sheets as well. I realize I can only orient it in two directions, but then again, my polarized sunglasses work pretty well and they are in a locked orientation... It might be worth a try. Just thinking through my options.


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## fish_shooter (Feb 11, 2015)

I just now measured 31mm from tick mark to tick mark (in white on the lens rear) on the rear of my 8-15mm. My guess is that a 30mm square filter will work fine.


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## mackguyver (Feb 12, 2015)

fish_shooter said:


> I just now measured 31mm from tick mark to tick mark (in white on the lens rear) on the rear of my 8-15mm. My guess is that a 30mm square filter will work fine.


Cool, and thanks so much for your help!


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## fugu82 (Feb 12, 2015)

I have cut gel filters for my Sigma 15mm from 3" Wratten squares. I avoided depositing any [non-removable] fingerprints on the gels by wearing nitrile gloves, but still managed to scratch them while using the supplied metal square as a template. Found the process to be an extreme PITA, and have wondered since why no one seems to sell them precut and packaged.


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## Marsu42 (Feb 12, 2015)

mackguyver said:


> Thanks, Marsu - and measurements would be nice if you happen to have a moment.



He was faster than me  ...



johnf3f said:


> For reference the guidelines on my 17-40 are 31mm square, hope this is of help.


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## mackguyver (Feb 13, 2015)

I ended up buying the Kodak Wratten 2 filter at ND 3.0. I'll report on the results...


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## LDS (Feb 13, 2015)

fugu82 said:


> but still managed to scratch them while using the supplied metal square as a template.



Put some kind of non-scratching paper between the template and the filter while cutting.


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## HKFEVER (Oct 13, 2016)

How to focus?

Focus then take off the lens, insert the filter than put back the lens?

Where to buy?


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## neuroanatomist (Oct 13, 2016)

HKFEVER said:


> How to focus?
> 
> Focus then take off the lens, insert the filter than put back the lens?
> 
> Where to buy?



Use Live View. 

B&H


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## old-pr-pix (Oct 13, 2016)

Didn't someone on here post a template? Maybe even mackguyver? Might be worth reposting or adding a link.

Trouble is these Wratten filters are made by Kodak and sold under license by Tiffen. Anything other than real common varieties may be hard to locate. For example, B&H lists the 89 series (infrared pass, visible block) but has no stock.


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