Elwood 8x10 modifications

[MTGseattle]

Since LFPF site is being bogged down I figured I would ask this over here.

My floor anchors for my Elwood column failed. (user error) and the working height with the thing sitting on the floor would have had me printing on my hands and knees I decided to tackle a side quest during my get the darkroom working again mission.

I have the Elwood mounted on the wall now, and I have a test led light source arriving today.

Question #1
Is there an optimal distance between light source and negative? In its "normal" form and using an Arista 1010 cold light, there was approximately 3 inches between the diffusion panel and the negative.
The diffusion panel in question is white acrylic that is 3/16" thick and was mounted to the posts that I guess held the original Elwood glass pieces.

Question #2 the diffusion panel is shiny on both sides. I would think that this is not ideal, but maybe it doesn't matter? I'm asking because I was thinking of using it again rather than driving across town to get a textured piece.

Question #3 can Newton rings occur regardless of light source type?

Not exactly a question #4 My thought as far as evaluating the diffusion panel was to take a given light source and incident meter that then take a reading of the same light shining though the diffusion piece. I figure if it's more than 2 stops different, I'll get a thinner piece.

 

[koraks]

Is there an optimal distance between light source and negative?

For enough for even illumination, not further than that because you just lose light. Other than that, doesn't really matter much - assuming a diffuse light source. For a condenser setup and/or point light source, different story altogether of course.

Question #2 the diffusion panel is shiny on both sides. I would think that this is not ideal, but maybe it doesn't matter?

I've worked with diffusers with shiny sides and never noticed any issue.

Question #3 can Newton rings occur regardless of light source type?

Yup. Newton rings are a function of two fairly smooth surfaces on top of each other. I can sort of see how they might be more or less apparent depending on a light source difference though. However, a diffuse light source does not make a setup immune to Newton rings.

 

[mshchem]

I agree with Koraks. If the light is diffuse no reason to move far away. The beautiful silvered dome of the original Elwood, along with the sandblasted glass diffusers were required to cope with hot light.

 

[MTGseattle]

Thank you both.

The Elwood I ended up with was already converted to cold light so no silvered dome, and none of the original glass pieces. I am dealing with a 7' ceiling in my darkroom so that is my motivation to get things as compact as possible.
My light source is delayed until tomorrow.

 

[mshchem]

Thank you both.

The Elwood I ended up with was already converted to cold light so no silvered dome, and none of the original glass pieces. I am dealing with a 7' ceiling in my darkroom so that is my motivation to get things as compact as possible.
My light source is delayed until tomorrow.

Please let us know how this all goes. I have a friend who still uses both 8x10 and 5x7 Elwoods, really neat machines.

 

[Don_ih]

I have a 5x7 Elwood and can't quite imagine dealing with one for 8x10, since the 5x7 is built like some kind of machinery you'd find in the engine room of a submarine - and almost as heavy. I've had it for 10 years and I think I've used it 5 times.

 

[ic-racer]

Light as close as possible without being in focus. Center of negative gets light from directly above and, the farther from the diffuser more and more relative contribution from the sides. Of course, as the diffuser is moved farther from the far edges, they will be relatively darker because no additional light from the limit of the diffuser coverage.
Gray test prints will show exactly what is happening.

 

[MattKing]

I have a 5x7 Elwood and can't quite imagine dealing with one for 8x10, since the 5x7 is built like some kind of machinery you'd find in the engine room of a submarine - and almost as heavy. I've had it for 10 years and I think I've used it 5 times.

It is funny Don, we have never met, but somehow when I read some of your posts, Richard Basehart comes to mind ...
https://www.imdb.com/title/tt0057798/?ref_=nm_ov_bio_lk

 

[Don_ih]

Richard Basehart

I'm not sure I've ever seen that guy in anything.

 

[Steve Goldstein]

<Richard Basehart> I'm not sure I've ever seen that guy in anything.

When I was a kid he was in the TV show "Voyage to the Bottom of the Sea".

 

[Don_ih]

When I was a kid he was in the TV show "Voyage to the Bottom of the Sea".

That's what Matt linked to. But I only had one broadcast channel when I was a kid.....

 

[MattKing]

The klaxon sound and the "Dive, Dive" announcement from that show is one of those childhood memories that are firmly enmeshed in the part of my memory reserved for trivia.

 

[MTGseattle]

Still no pictures. Sorry. My light arrived. I've got things mocked up enough that I was able to perform a test of concept at least.
I have alignment concerns. The big steel elevation plate should be at 90 degrees to the floor, mine is at 89.5. The casting that makes up the top is not perfectly flat along either axis and I think the one original negative holder I have (aluminum I think)? is also not perfectly flat.

If I want to get silly, I can shim between my wood mount assembly and the steel elevation plate and try and get 90 degrees there.

For the negative holder, I guess I could shim the glass plate in the aluminum.

There are strategies for getting past the alignment issues at any rate.

The light I ordered is a Neewer NL660. Yes, the one that the naked photographer tested. It is smaller than an 8x10 negative so my strategy of literally setting the neewer directly onto my diffusion plate is going to cause some fall off. I also have a ton of light being lost to open space since my opening above the negative is 10x10, the diffusion plate is 12x12 and the Neewer is I think 8x9
I'll need to assemble a separate box for the light that closes up all of the extra diffusion material.

I did get everything powered up and am able to place my easel on a table and focus an image, that was the main goal of this madness; not printing on my hands and knees.

Will I be able to get a print in focus across the whole image? Time will tell.

Oh, the lens I have for 8x10 work right now is an Apo-Nikkor 240mm.