Center filter recommendation for 240 g-claron on 8x10?

[John NYC]

I think I want to try out using a center filter for my color night shots using my 240 g-claron on 8x10. Any particular recommendations for one versus another?

Thanks.

John

[Bob Salomon]

You just need one that screws into the lens. Since no CFs were made for that type of lens they will all be about the same.

[John NYC]

There are a bunch of Schneider CFs out there in 52mm size for various traditional and digital lenses (35/5.6, 47/5.6, 24mm Digitar, 35mm Digitar). What are the differences? You are hinting that they will all equally be not-so-useful on the g-claron?

[Lachlan 717]

Is it really worth the loss of 1.5-2 stops in already very low light? Reciprocity and colour shift (film, no filter induced) would outweigh any benefits in my world....

[Dave Wooten]

you probably won't need a center filter.

[John NYC]

I already take night shots without the center filter, so I know I don't *need* it but I want to to try it. With what I am doing, I am not worried about color shifts. At 2-12 minutes shooting off New York roofs, you are going to get color shifts without worrying about another stop, especially on the ones that I shoot at the lower range of that scale.

So back to the original question, any technical reason why one of those Schneiders might work better than another?

[Eric Leppanen]

My 240mm Germinar W (very similar design to the G-Claron, aside from its 49mm front filter thread) works well with a Schneider #2 (older version) center filter, see:

http://www.apug.org/forums/forum44/26539-center-filter-240mm-germinar-w-lens.html

Don Hutton has also had good results with the Germinar/#2 combination, see:

http://www.largeformatphotography.info/forum/showthread.php?t=45577&highlight=germinar+center+filter

I would suggest getting the closest 52mm filter thread counterpart to the #2 and give it a try.

[John NYC]

My 240mm Germinar W (very similar design to the G-Claron, aside from its 49mm front filter thread) works well with a Schneider #2 (older version) center filter, see:

http://www.apug.org/forums/forum44/26539-center-filter-240mm-germinar-w-lens.html

I would suggest getting the closest 52mm filter thread counterpart to the #2 and give it a try.

Thanks, Eric. This is similar to the one you have?

http://www.adorama.com/SRCF4756.html

[Drew Wiley]

There is a little falloff with the 250 on 8X10, but all the center filters I own would
over-correct for it. I was out shooting in the redwoods and mist with a 250 G on my
8x10 today. To get good coverage I usually have to stop it down to at least f/32 or
more likely f/45. I have made big Cibachrome prints from film with this combination, which is certainly a contrasty media, but have never had a problem
after simple contrast masking. I wouldn't worry much about it.

[John NYC]

There is a little falloff with the 250 on 8X10, but all the center filters I own would
over-correct for it. I was out shooting in the redwoods and mist with a 250 G on my
8x10 today. To get good coverage I usually have to stop it down to at least f/32 or
more likely f/45. I have made big Cibachrome prints from film with this combination, which is certainly a contrasty media, but have never had a problem
after simple contrast masking. I wouldn't worry much about it.

I've tested aperture values, and f/22 is the farthest I can stop down and still get the results I want for the subject matter I am shooting and under the circumstances I am shooting in.

Do you own a 1.5 stop center filter? Or are all the ones you own stronger than that?

[Eric Leppanen]

Thanks, Eric. This is similar to the one you have?

http://www.adorama.com/SRCF4756.htmlFrom just looking at the specs, it appears to be very similar to mine. Since you will be shooting at f/22, I assume you will not be using major movements (otherwise your G-Claron will run out of coverage), so hopefully filter vignetting will not be a problem for you. It's not a factor for my Germinar unless I use extreme movements.

[Drew Wiley]

John - I haven't done any definitive tests with a densitometer, but I am quite certain
that a CF with 1-1/2 stops would be too much correction for this particular lens/format combination. And yes, I do have a CF on hand with this degree of correction.
It is not unusal for me to require a reasonable amount of rise which forces me into
a smaller stop than f/22, along with depth of field issues. Also, at the extreme corners of 8x10 film you would getter a little better resolution at a smaller aperture with this particular lens. But if you're mainly only using back tilts, and no significant
movement otherwise, the lens will be fine. I enlarge up to 30x40, so try to get the
very most performance out of the lens possible. On a 16x20 you're not going to note
much difference, unless depth of field is compromised. This is not a lens for extreme architectural movements, but performs very nicely in most situations.

[John NYC]

John - I haven't done any definitive tests with a densitometer, but I am quite certain
that a CF with 1-1/2 stops would be too much correction for this particular lens/format combination. And yes, I do have a CF on hand with this degree of correction.
It is not unusal for me to require a reasonable amount of rise which forces me into
a smaller stop than f/22, along with depth of field issues. Also, at the extreme corners of 8x10 film you would getter a little better resolution at a smaller aperture with this particular lens. But if you're mainly only using back tilts, and no significant
movement otherwise, the lens will be fine. I enlarge up to 30x40, so try to get the
very most performance out of the lens possible. On a 16x20 you're not going to note
much difference, unless depth of field is compromised. This is not a lens for extreme architectural movements, but performs very nicely in most situations.

I appreciate your advice, as it seems you are trying to spare me the expense for something you find not necessary in your work... (which is very nice by the way!)

I've been using this, my only lens, for seven months on 8x10, and I feel like I know what its pros and cons are. I am not looking to blindly put the center filter on this lens for every shot. Rather I am looking to solve some specific scenarios I am encountering in a few of my night shots, where the illumination is more concentrated in the center of the frame but I want to be able to bring the sides up into "zone III" without blowing out the center... so it is not just lens characteristics under even illumination I am trying to compensate for. Perhaps it won't work to solve the issue, but I am willing to risk the $250 to try it out if it can make some of these attempts that failed work. That is a small premium compared to the amount of money spent on film for this. If it doesn't work, people can be on the lookout for a barely used center filter on the forum classifieds. ;-)

[John NYC]

From just looking at the specs, it appears to be very similar to mine. Since you will be shooting at f/22, I assume you will not be using major movements (otherwise your G-Claron will run out of coverage), so hopefully filter vignetting will not be a problem for you. It's not a factor for my Germinar unless I use extreme movements.

I have not run out of coverage yet in any of my shots at f/22; very modest movements... some modest rise or fall and occasionally a hair of tilt.

Thanks muchly for the input. I'm going to order it and try it in some specific scenarios and see what it does for me.