Qualities of Light as related to enlarging

For those who may be interested, Durst Pro/Jensen Optical has a new website up and operationg. http://durst-pro-usa.com/

If you wish to explore the qualites of light as applies to enlarging of photographic images, Mr. Jensen has what I consider one of the best explanations currently available on the subject. You can find this explanation by clicking on the library link and then going to the technical section and clicking on "something about Bill Clinton and light heads".

I hope that you find this meaningful.

Crap, my negatives are bleeding! Get out the band aids LOL. Just joking, excellent article, thanks for pointing it out. I have both diffusion and condenser enlargers in my darkroom. Each has it's benefits, but I'm finding I print my PyroCat-HD negs on the condenser enlarger.

Just thru my own experimentation I found that the minimal exposure/development regime worked best for the kind of landscapes I was doing in combination with pyro and the condenser.

But now I have to align the bulb in my condenser enlarger! Ignorance was bliss LOL.

There is a lot to digest in that paper. Well worth reading.

Excellent article(s). I think many people would understand a lot more about the science behind enlarging, if they read at least some of the articles attached to this site.

I haven't read all of the article(s), so far I haven't come across anything yet that wasn't very clearly explained and shown, top notch.

Mick.

Thanks for the new web address. Does anyone have a updated evaluation of their 5x7 light source?

Jim

The article has an analogy which incompletely describes the optical situation of an enlarger. The main emphasis is comparing the shadows cast by an object when illuminated by either a collimated light source (e.g., the sun) or a diffused light source. The collimiated light source casts a shadow with sharp edges, while the diffused light source sends light rays in more directions and casts a shadow with fuzzy edges. But what this ignores is that the enlarger lens is focused on the negative, to create a sharp image of the negative on the print. When light rays originate from one point on the negative, traveling in various directions to arrive over the entrance pupil of the lens, they are focused by the lens to one point on the print to create a sharp image. Going back to the original analogy, of a fuzzy shadow of a hand cast by a diffuse light source -- if you put your eye at the location of the shaow and look back at the hand, you would see a sharp edge, not a fuzzy one, depite the diffuse light source.

Donald Miller said:

For those who may be interested, Durst Pro/Jensen Optical has a new website up and operationg. http://durst-pro-usa.com/

If you wish to explore the qualites of light as applies to enlarging of photographic images, Mr. Jensen has what I consider one of the best explanations currently available on the subject. You can find this explanation by clicking on the library link and then going to the technical section and clicking on "something about Bill Clinton and light heads".

I hope that you find this meaningful.

Click to expand...

Thanks for the link. I have a medium format diffusion enlarger and a large format sized condenser enlarger, and I can't make up my mind which one I prefer!

Pat

A condenser and diffusion will make equal prints if you make your neg to match it, not to contrasty and sufficient shadow detail for the condensor and contrasty enough to print on the same paper with diffusion.

They will not be exactly the same, but close enough that you need to see them both side by side to see differences in tonal scale. From 35mm, the condensor will have more grain, both will be equally sharp.