How does a Cambo film camera with a 300 mm lens turn into a Condenser Type of enlarger- are you kidding here?
How does a Cambo film camera with a 300 mm lens turn into a Condenser Type of enlarger- are you kidding here?
Hello Bob,Originally Posted by bob carnie
No kidding at all:
https://www.flickr.com/photos/125592...posted-public/
In this picture a LOMO 600 is in place, but it needs monocrhome green light (I guess) to perform without chromatic aberration so I used the Sironar to use filters for the variable contrast paper.
Mr Ansel Adams "told me" how to do it
https://www.flickr.com/photos/fredjohnson/2465540103
Of couse I placed paper on the wall... like Mr Adams...
The "condenser type" was implemented by using as slide projector to throw light across the negative it's a good idea !!
Regards.
PD: During lots of decades photographers were using the view camera as his enlarger. This is very well known...
I'm to prepare a youtube video next month with the tips, I found it can be useful for people that cannot own an 8x10" enlarger.
I had some falloff, I plan to solve if with a plastic fresnel to drive most of light from the negative to the lens pupil.
I have no doubt about a few things.
One of those things is that I am pretty sure you are a bit out there with your photography, and your flicker link pretty much tells me all I need to know about your working methods.
Bob, I'm learning and experimenting, I'm taking a lot of fun, and I'm very happy. I'm not a professional, and don't sell my work. Just I enjoy making photographs and viewing other's work.
My tools are not the best by far, but this has little importance to me, when I've a material limitation I try to remember that Michelangelo made the Pietà with a bare hammer...
Anyway, congratulations for having better tools and working methods, I seen your work and it is great.
If you want to discuss the objective quality parameters from a contact print, I'm open, please quote any of the statements (Resolution, Microcontrast) I made before if you don't agree.
The OP is asking about the quality of contact prints made directly from in-camera negatives.
I have a very precise answer to that:
The image quality will be some 50 Lp/mm with Ilford MG RC paper, in USAF 1951 terms, if that Image Quality is also present in the negative. (A human wiever don't notice quality beyond 7 Lp/mm, in high contrast conditions) To compare, a print 1:1 from an enlarger may render 20Lp/mm, also in USAF 1951 terms.
Probably the negative won't reach that level, for the moment a common ULF lens with such image circle won't perform 50Lp/mm in practice, later consider corners, focus, small aperture, shake, wind...
Also film can be a limitation, in practice for a +50Lp/mm sharp ULF film you have to go Ilford, say Delta 100:
http://www.ilfordphoto.com/Webfiles/...1435591962.pdf
Fiber Based paper will deliver a bit lower resolution, but it won't be noticed at all without a magnifier.
About microcontrast, it will be slightly higher than with a condenser enlarger, and a bit more difference with difusser enlarger, I can't say how much numerically. Has anybody numbers for that?
Pere
One of my mentors told me very early not to argue with others on the internet, as a small business owner I have found his advice to be of great value since joining this site over 12 years.
good luck with your journeys in photography, right now I do not have interest in discussing the objective quality parameters from a contact print with you.
thank you for thinking my work is great, I would suggest a good place to learn and experiment here is by posting images of your work and there are many here who will help you with constructive critiques .
Bob
Whether 7 or 5 or 10, I've always felt those low numbers to be rather misleading. My experience correlates very well with 30 lp/mm when discussing the ultimate sharpness one can see in contact prints on the most capable silver gelatin papers. I'm not alone in that position. Read pages 1 through 4 here:
Thanks, I'll do it.
For the moment I've only two 8x10 negatives, both are well exposed and developed IMHO, I'm working with both in the darkroom, contact printing, to obtain a good result. For the moment with RC paper to learn.
https://www.flickr.com/photos/125592...posted-public/
https://www.flickr.com/photos/125592...posted-public/
I have to make better size reductions, I've jpg artifacts, then I'll post both here to get advice.
First, This depends on the sight score every person have, and if one has a bit near-sightedness then one can see the print closer.
Thanks for the link. I've saved it and I'll read more in the future.
Yes, in your link I found that:
"In other words, the resolution
difference between 10 lp/mm of sharp edges and
fuzzy ones is way down around 30 lp/mm. When
we notice a difference between those blurry and
sharp 10 lp/mm lines, we are responding to detail
at 30 lp/mm, even though we can’t directly see it."
But this numbers have little meaning, first because there are almost no photographic subject that have 1:1000 or even 1:100 microcontrast that can take advantage of 10 or 30 Lp/mm. A strong illuminated area can be at 8 stops of a shadow, but in each area "internal" contrast will be much lower, This then goes compressed to a negative in terms of density.
Also a print paper can render less than 1:100 reflective density contrast, this with total white strips/dots at the side at the side of total black strips/dots, this is a near imposible situation with photographic subjects, in practice. For this reason the 7 Lp/mm is assumed as the practical limit. If you have "tonality" in your print... beyond 7Lp/mm one has to be an eagle...
This is what I understand, I may be mistaken, please reply me if what I say is not correct, this is that in practice a print has not the 1:1000 microcontrast, but perhaps 1:20, that will not allow to feel 30Lp/mm but only 7Lp/mm.
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