Develop film shot with red filter

biakalt

biakalt

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Hi all!

I'm about to try out red filter for a first time. what i have here is B+W 090 5x red filter. I'm gonna shoot it with Tri-X. according to this page, I would have to compensate 2 1/3 of the f/stop. does that mean when I process the film, I'd have to process at box speed (ISO 400) or process it at ISO 80 (2 1/3 of the f/stop)?

thank you in advance
 
biakalt said:
Hi all!

does that mean when I process the film, I'd have to process at box speed (ISO 400) or process it at ISO 80 (2 1/3 of the f/stop)?

thank you in advance
Click to expand...

No, you process at box speed. If your camera meters TTL, you shoot it at box speed ('cause your meter is behind the filter). If you are not metering TTL, you expose as if you were loaded with ISO 80.
 
No, it means that you have to give the film 2 1/3 more stops of exposure. If you are going to shoot the whole roll with the filter on, one way to achieve that is to set your light meter to 80 ISO.

Edit - yes as Proteus617 points out, with TTL meter just expose at box speed with the meter set to box speed. If using a separate meter set the meter to 80 ISO.
 
Everybody already explained the technical stuff. Take the "add two and a third f-stop" advice with a grain of salt though. In situations where there is MORE red light, such as the 'golden hour' or indoors under incandescent light (does anybody still have those?) you will need to compensate LESS than the rated filter factor. Filter factors are generally rated for midday outdoor light.

To get really dramatic skies (which is often the reason to use a red filter with panchromatic film) underexpose a bit more than the factor suggests. Clouds, especially the billowy cumulus kind will really stand out when they are sunlit, against a very dark gray sky. If you are shooting people (especially girls, whose skin is often redder than most male's skin) give it a bit of overexposure. This'll make 'em glow.

I like to push film I shoot with a red filter, as it increases the contrast even more. ut then I like a contrasty negative. All of this advice is my opinion only, and is what i do to get my own particular look. You will, of course want to experiment as you get into filtered light shooting. It's a fantastic world and welcome to the red side! 😉
 
Beware that in my experience built in meters don't compensate correctly for red filters. Using an external meter is better, or meter without the filter and then add 3 stops gives good exposures.
 
thank you all for the inputs! i'm just trying to get some really dark sky against the cloud cos it's been real sunny here recently in the UK. some of my shot recently of the sky has been really flat. hopefully it'll turn out alright. i'll post some results after the experiment. grain and mad contrast are what i'm after 😀
 
Remember the red filter will darken green a lot (grass and trees).

If you're metering with TTL in camera, just expose and develop as you always do.

If you meter handheld incident, give the film 2 1/2 stops more light, and develop as you always do.

Cheers,

Juan
 
biakalt said:
...I would have to compensate 2 1/3 of the f/stop. does that mean when I process the film, I'd have to process at box speed (ISO 400) or process it at ISO 80 (2 1/3 of the f/stop)?...
Click to expand...

No, you've got it backward. You would need to process the film at ISO 2000 if you wanted to do the exposure correction in development.

You are probably better off doing as others have said by making the filter correction with the camera exposure. Either metering through the filter so that the meter corrects, or metering without the filter using an ISO setting of 80.

Also, as mentioned already, the color of the subject and the effect you wish to accomplish have a major impact on how you should expose. Published filter factors are only approximations based on typical usage; your mileage may vary. Until you are much more familiar with the filter and its affect, I suggest that you bracket your exposures.
 
Compensating with development (and not with exposure) just can't be done... If you expose film near three stops below perfect exposure, your frames will be a waste no matter the development, if we talk about image quality... With your M6 just shoot and develop as always...

Cheers,

Juan
 
I push too, and I know what I lose. Salgado knew it too. And of course his normal shooting wasn't tipically underexposing five or six stops... But go ahead and do it...


About the plane image: that's a shot with very high contrast, grossly underexposed, and done to get that sky and clouds separation on a sunny day. Everything's darkened. Maybe digitally treated and not a real print from the negative... That push procedure, if used with 99% normal photography, is useless for obtaining a quality negative. You make black out of half the world...


The other image shows a horrible contrast too, at least to my taste. Why push ISO100 film to ISO1600 if there's fast film? Trying to push ISO3200 film one or two stops in low light, losing shadow detail when there's no other option, but yet with great quality for wet printing, is something I understand and do... I shoot TMZ at 6400 constantly...



Underexposing film three stops, and overdeveloping it, brings only high values up. No more... The general IQ is very poor.


If you like it, just do it, and scan, and process, and print digitally. I don't enjoy that game...


Cheers,


Juan
 
Chris101 said:
Everybody already explained the technical stuff. Take the "add two and a third f-stop" advice with a grain of salt though. In situations where there is MORE red light, such as the 'golden hour' or indoors under incandescent light (does anybody still have those?) you will need to compensate LESS than the rated filter factor. Filter factors are generally rated for midday outdoor light.

To get really dramatic skies (which is often the reason to use a red filter with panchromatic film) underexpose a bit more than the factor suggests. Clouds, especially the billowy cumulus kind will really stand out when they are sunlit, against a very dark gray sky. If you are shooting people (especially girls, whose skin is often redder than most male's skin) give it a bit of overexposure. This'll make 'em glow.

I like to push film I shoot with a red filter, as it increases the contrast even more. ut then I like a contrasty negative. All of this advice is my opinion only, and is what i do to get my own particular look. You will, of course want to experiment as you get into filtered light shooting. It's a fantastic world and welcome to the red side! 😉
Click to expand...

I still have incandescent lights, but to add, as you say dark skies are the big reason for using this filter. I find I get better results if I make sure the sun is to my back. And as Juan says red filters darken blue so you will lose shadows as they are light by blue sky. This makes your prints have higher contrast. But it seems, you lose something every time you try to gain something in photography.
 
My M6 does not expose right through the lens with red filter.

Measure with external meter to whatever ASA you develop for, and add 3 stops.

Roland.
 
thank you all! i sometimes push too but the sky from those pushed shot just doesnt 'do' it for me. what im looking for is this kind of sky (shot by Julius Shulman) with great tonal gradient and separation from the clouds.
wow, you guys push 4-5 stops? the negs must be incredibly thin! my maximum push with tri-x is 3 stops (soup in 1+100 Rodinal for an hour) and beyond that their just blackness...
so combining pushing film + red filter is doable. that sounds really interesting.
 
biakalt said:
thank you all! i sometimes push too but the sky from those pushed shot just doesnt 'do' it for me. what im looking for is this kind of sky (shot by Julius Shulman) with great tonal gradient and separation from the clouds.
wow, you guys push 4-5 stops? the negs must be incredibly thin! my maximum push with tri-x is 3 stops (soup in 1+100 Rodinal for an hour) and beyond that their just blackness...
so combining pushing film + red filter is doable. that sounds really interesting.
Click to expand...

Even though that is IR, you can still get shots like that with TriX. If I were doing it especially for the first time; I would determine the factor for my filter, in your case that would be 2 1/3 stops. I would then figure that 'new EI' for my film. I shoot TriX at 250 so that would be 50 for my new EI: for 400 it would be 80 EI. Set your handheld meter at that EI/ISO. With your red filter on your camera, meter the scene handheld and set your camera to those readings. You can develop the roll in your normal manner that produces the tonality that you like. As has been said you will lose some shadows and the grass will be darkened but you still should be OK. This is TriX with a red filter:

3968166796_330f3ddef7.jpg


I'm not a big fan of over darkened skies so I did shoot this with some compensation for that.
 
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On my digi p&s a red filter gets me serious underexposure which I don't get with other filters. I would be circumspect about ttl metering, perhaps with a test roll.
 
Confirming lorriman (and as I said above wrt M6) - TTL metering will not work. The typical camera meter is more sensitive to the other side of the spectrum. And B+W 090 means 3 stops. Of course it all depends on the subject matter, and a test roll never hurts.

Roland.
 
sonofdanang said:
Good grief! Film is cheap, people. Don't shoot test rolls, shoot frames that you would keep, should they work out. Bracket the snot out of it and have a look either by scanning or contact print. Find out where it 'pops' for you.
Click to expand...

Nothing against bracketing, but sometimes it's inconvenient.

809668621_oGJX9-L.jpg


(Neopan 400 @ 250, Rodinal 1:100, Red Filter).
 
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