Let’s start over
I will never buy a Center Filter
Very few ever made and I think all are out of production
Worse they are specifically for one lens only
I was contact printing. I removed the lens on 57 Elwood as I wanted less lamp falloff. I made pencil spot drawing on tracing plastic drawing
To make light projection better
Good luck
BTW. Where are you
I am in Illinois
Tin Can
Some CND filters were made with a specific lens in mind, but that doesn't mean that they can't be used on other lenses.
Plus many CND filters were not made with any specific lens in mind at all. The many Hoya and Heliopan CND filters are good examples.
http://www.subclub.org/fujinon/center5.htm
You select a CF in relation to the amount of falloff, typically at a standarized stop of f/22, or perhaps f/16 with especially short focal lengths. Most correct for a stop and a half of falloff, some for two whole stops. But otherwise, if they thread on, you can interchange them between different brand lenses of comparable falloff. I've done that numerous times, especially in relation to architectural photography when repro standards needed to be pretty tight. Most clients weren't looking for some artsy look with black corners. For personal work, you can do anything you please.
I do not mean to be rude, but I still fail to understand what of your statements have something to do with the topic. I mean, it is ok if you do not like CND filters, or if few were made or if you will never buy one. I make an effort to communicate (although english is not my first language and I am sure I make many mistakes). Please, if you want to reply organize your thoughts first. Do you believe that my DIY CND filter will cause a lot of loss of contrast? Do you have any experience in the matter at hand that could be beneficial? I suspect that your statements about pencil drawings on tracing paper are on topic, but I struggle a lot to figure out what do you mean.
I am Spain based.
Hopefully one our esteemed old members come to your rescue
I am done
Over and out
Tin Can
Tin is referring to the methods used to reduce the effect of light fall-off. There are different ways to do this, and it is not only used to deal with light fall-off. It is used in high contrast scenes, as well, and for dealing will improperly exposed or developed negatives and slides. Two approaches are to make a masking negative from film -- or adding graphite to the "problem" negative itself (painting the negative). Approaches like that can minimize the problem, but not totally solve it -- and take a lot of time and effort, and skill.
One of my suggested approaches is the opposite -- over expose the film and DODGE the print. Not perfect, but a lot cheaper than CND filters -- see link above. With this method, you are not trying to "recover" what's not there, you are trying to minimize what is there.
Last edited by xkaes; 30-Jan-2024 at 19:05.
Concentric rings 'might' work better than dots. No good choices here. Whatever shape you might use, as you stop down and are using more of center, where the concentration of opacity exists, the optical problems will increase. As the geometry gets smaller, the pattern will act more like a diffraction grating. Not good. Still, it's an intriguing idea.
How about you print one onto a glass plate? Do they still make glass plates?
my picture blog
ejwoodbury.blogspot.com
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