Beseler 8x10 conversion?

[Ash]

Here we go, the final outcome.


This is what the enlarger should look like, sat atop the mock-up...




The half completed box...




The lower box and the top platform aren't entirely parallel - I messed up, but everything else is fine. I used two bolts that sit inside the box (that originally bolt up the condenser stage to a bar) to hold the thing in place.

The inside needs spraying white, and the outside blue or grey


The final thing...




I don't have any shots with the lights off and the enlarger on just yet. I'll be doing that shortly!


I know of at least one light leak I need to sort (the bottom of the box onto the condenser stage). That should be fine though.

[Ash]

I have run into a problem with illumination. With the Opal diffuser at the top, there's too much shadow and vignetting by the time light hits the neg.

I removed the Opal square from the top, that gave me really nice bright light, but hot spots.

I took a moment to think about the original design (and thinking of my LPL 6700, and the DeVere 504 at college) and it's obvious that the diffuser needs to be directly above the negative, regardless of the height of the light box.

I placed a piece of plain copier paper over the neg, perfect diffusion but I lost about two stops of light.



So I've sent an email to a supplier of custom opal glass to try and get a piece cut, and that will be permanently placed in the enlarger.


Realising I had a spare Whole-Plate ground glass, I've placed that on top of the neg carrier and it seems to provide even illumination currently.

Might need to sort out these light leaks though

[ic-racer]

I didn't realize that Chromega is so big .

Your adapter is looking great so far! As you have discovered, the closer you can get that diffuser to the negative the less of a center hotspot.

[Ash]

Thanks ic-racer

I've attached a basic counterweight system (tying some extension cable to the front handles and hanging a 6kg metal weight over the back). It's reduced the strain on the front platforms but it's not uniform and it's very ugly!

When I get the time and materials, I'll have hooks off the shed ceiling to hang the cables through and uniformly keep the weight off the enlarger.

[Claude Sapp]

The neg carrier for my Beseler 8x10 enlarger is a 12"x12" clamshell of a piece of clear glass on the bottom, and a white plastic diffuser on the top. The two pieces sandwich the negative in the middle of the glass and diffuser, and this carrier slides into the enlarger head. Can't get the diffuser any closer to the negative than this setup.

[Ash]

Hi Claude - I remember that from the photo's you sent

With mine I have a negaflat (?) holder which tension-holds the negative, no glass required

[Ash]

I bought but have not figured out how to pick up yet an 8x10 Elwood Enlarger.

I then bought a 24-case (partly to resell) of 300W PS35 internal frost lamps after reading the Elwood patent (1927) that says they work great.

The 1940-ish manual says they DON'T, & to only use OPAL.

Maybe they didn't have OPAL in 1927, or Elwood liked hot spots back then & thought they looked normal!

So I will probably need to enhance the existing sandblasted glass diffuser that is heavily blasted at the hot spot.

I considered flashed opal glass, but
1) only have an 8x10 piece, and the existing diffuser is 11x11
2) should wait until I actually have the enlarger (!)

So, I'm wondering what kind of light source is in your Beseler?

Hey Murray, hope you don't mind me replying publicly

The original Beseler lamphouse was a column with a light fixture at the top (incandescent) with two HUGE condenser lenses below.

This Chromega head uses three halogen bulbs (facing sideways), with styrofoam reflectors (at 30-40 degrees) to reflect the light downwards. That light then 'evenly' illuminates an opal sheet, that from what I can see is a sandwich of glass and plastic.


If I were you, get the enlarger home, then open up the lamphouse on top and see how it's wired. You could do as the Chromega does and have the lights on the side (indirect, bouncing the light) or have them from the top (but high enough not to get hotspots). Either way, placing a diffuser directly above or on top of the negative should even out the light.

I don't know anything about the Elwood, or I'd try and be more help....I'm sure if I can't be more help then some of the other members can!

[Murray]

That IS big.

Diffuser A.C.A.P. to the neg is the key it looks like.

I get 2 stops loss with 92 brightness printer paper as a flash diffuser too.

Thanks