Omega B-22 XL questions

[Adrian Bacon]

A couple weeks ago I picked up an Omega B-22 from a local fellow via eBay for $37. It’s complete except for negative carriers and timer. I’ve taken it apart, given it a thorough cleaning, gotten a timer for it and carriers, ordered some bulbs (the one it has works, but has a discolored/burned spot on one side, so I’ll just replace it when the new one arrives), and set it up on a little rolling cart that I can roll into the laundry room at my house, which makes for a near perfect home darkroom. Even though I have a dedicated darkroom at my lab, printing late into the night at the lab can often interfere with domestic expectations because you’re not home. Cue portable darkroom at home via the B-22. It has a 50mm lens and the supplementary condenser element for 35mm.

OK, the questions: man that’s a lot of light. I generally prefer my exposure times with a grade 3 filter to be in the 10-20 second range to get an acceptable black with film base plus fog. Stopped all the way down is still too much light. Is there an easy way to cut the light down that won’t introduce textures or patterns into the prints? Most of what I’m planning to print is 3.5x5 and 5x7 from 35mm negs (again family snaps to go into albums).

Question 2: the contrast I’m getting on a print is a lot higher than with my dichroic diffusion enlargers at the lab. Is there a way to make the light more diffuse without introducing patterns and textures into the print?

I’ve tried a sheet of semi transparent duralar under the bottom condenser and it cuts the light, but introduces patterns. I’ve put a piece of that material in the filter drawer, and it also cuts the light, but doesn’t really seem to tame the contrast in any meaningful way. I still have to print with a grade 0 or 1 as opposed to a 2-3 with the other enlargers. I also prefer the diffusion light source look over how the condenser looks, print-wise. There’s nothing wrong with the look of the print with the B-22, it’s just a preference thing.

I’m not looking to spend a huge amount of cash, given that this is for personal family snaps and stuff, so will live with it if there’s no easy way around the light source, but thought I’d put it out here if anybody else has some experience/insights with this particular little guy.

All that being said, the B-22 is a great little enlarger, and overall, I’m pretty happy with it, and my spouse is also happy that I’m not out until the wee hours.

 

[MattKing]

IIRC, there were/are two bulb options for the B-22 - you should check whether you have the lower output option.
KHB has lots of info: http://www.khbphotografix.com/omega/Enlargers/B22.htm

 

[Pieter12]

An ND gel of your choice in the filter drawer.

 

[Paul Howell]

I switched to Standard LED, GE Classic 1200 and 1600, the 1200 gives me grade 2 with Ilford filter. In terms of converting your B22 to a diffusion enlarger you need a mixing box of some sort and replace the condenser. I have 2 diffusion enlargers, a LPL with color head and a Federal Stow Away Jr. The Federal was made in 40s and 50s, it was a bottom feeder, clear bulb, white opal glass, built in 2 element built lens with waterhouse stops. It takes negatives up to 6X9, produces a really soft image, not fuzzy, just softer. With the right negative it works oddly well. Omega made a cold light the D series, maybe they made a cold light for the Bs, but also need a corresponding electric shutter for it work well.

 

[Adrian Bacon]

IIRC, there were/are two bulb options for the B-22 - you should check whether you have the lower output option.
KHB has lots of info: http://www.khbphotografix.com/omega/Enlargers/B22.htm

There’s only one bulb for the condenser, though, (the second bulb is for the dichroic Lamphouse) looking at the list of parts at the link you provided gives me some ideas to look into.

 

[Adrian Bacon]

An ND gel of your choice in the filter drawer.

That could work, but I’d like to kill two birds with one stone, cut the light output, and get it a bit more diffuse. So far everything I’ve tried has only cut the light output.

 

[MattKing]

You could try it without the supplementary condenser for 35mm.
Light output would be reduced, and any added flare would probably help with contrast.

 

[Adrian Bacon]

You could try it without the supplementary condenser for 35mm.
Light output would be reduced, and any added flare would probably help with contrast.

I never even thought of that. You could technically use a wider angle lens for a smaller format with the condenser configured for a longer lens/larger format. I don’t have to have the supplementary adapter in there.

On the link you sent, I noticed that there’s a 3.5 inch opal glass accessory available. It makes me wonder if that could be of some use above the condenser assembly. I might take the 35mm condenser glass out and just put a piece of of the semi-transparent duralar on top of the top condenser lens to see what effect that may have.

 

[choiliefan]

Is it possible to use a dimmer switch with your machine?
Some of the Beselers used a variable rheostat for this purpose, no?
https://www.lowes.com/pd/Lutron-Rot...VBW6GCh338QFUEAYYBCABEgIcsPD_BwE&gclsrc=aw.ds

 

[Adrian Bacon]

Is it possible to use a dimmer switch with your machine?
Some of the Beselers used a variable rheostat for this purpose, no?
https://www.lowes.com/pd/Lutron-Rotary-600-Watt-Single-Pole-White-Ivory-Dimmer/1059607?cm_mmc=shp-_-c-_-prd-_-rpe-_-google-_-lia-_--_-dimmersandspecialtydevices-_-1059607-_-0&store_code=647&cm_mmc=src-_-c-_-prd-_-rpe-_-google-_-rough_plumbing_and_electrical-_-MHLIA_RPE_Rough Plumbing and Electrical_Low Priority-_--_-0-_-0&gclid=EAIaIQobChMIgvuysKPl5QIVBW6GCh338QFUEAYYBCABEgIcsPD_BwE&gclsrc=aw.ds

I don’t see why not. It could go between the timer and the light. There’s no voltage stabilizer or anything. It’s essentially not much different than a (very bright) desk lamp.

This is actually a good idea, and will give me pretty fine control to print at a constant light level.

 

[Pieter12]

Does a dimmer affect the color temperature? That might mess with your VC filters.

 

[MattKing]

Adjusting the rheostat may change the colour temperature of the lamp in a way that will affect contrast.

 

[Adrian Bacon]

Adjusting the rheostat may change the colour temperature of the lamp in a way that will affect contrast.

I’ll have to do some research into how much the color temperature changes when dimming a halogen/incandescent bulb.

 

[Adrian Bacon]

According to Wikipedia, the color temperature is proportionate to voltage: https://en.m.wikipedia.org/wiki/Incandescent_light_bulb

See light output and lifetime section in linked article.

 

[MattKing]

I’ll have to do some research into how much the color temperature changes when dimming a halogen/incandescent bulb.

It shouldn't be too much of a problem if you just pick one or two settings (high and low?), and then calibrate your results at each of those settings.
I wouldn't recommend many different settings, with accompanying different colour temperatures.

 

[Pieter12]

The original 111A bulb is only 75W, not sure why this is too bright for you. You may have to change the socket since the 111A is a bayonet base. For some diffusion, Omega did have a 3-1/2" opal glass--you might find it on *bay, or make something yourself.

 

[Adrian Bacon]

It shouldn't be too much of a problem if you just pick one or two settings (high and low?), and then calibrate your results at each of those settings.
I wouldn't recommend many different settings, with accompanying different colour temperatures.

True. If anything, since dimming warms the light as you dim it, it’ll help my contrast,

I tried no supplementary condenser last night and it knocked a fair amount of light off, but didn’t really change contrast. My test image still printed at 0.5, versus 1.5 using the same under the lens filters on a diffusion enlarger. I then added a disk of Duralar on top of the condenser, and it knocked more light out, but introduced a relatively heavy vignette, so I went with the Duralar in the filter drawer instead and got the vignette back to 4/10ths of a stop. With the supplementary 35mm condenser and no Duralar anywhere, the vignette is 3/10ths of a stop from the center to the edge of the frame along the long axis.

Vignette aside, the Duralar above the condenser does not seem to have an effect on contrast, as I’m still printing the same negative with 0.5 no matter what I do.

 

[Adrian Bacon]

The original 111A bulb is only 75W, not sure why this is too bright for you. You may have to change the socket since the 111A is a bayonet base. For some diffusion, Omega did have a 3-1/2" opal glass--you might find it on *bay, or make something yourself.

Only 75W is relative. I’m printing 35mm negs onto 3.5x5 and 5x7 paper. That little enlarger is throwing down nearly 200 lux into that little area with the lens stopped all the way down. Normal printing lux levels are in the 5-20 lux range.

 

[Pieter12]

From the Ilford Multigrade filter info sheet:
MULTIGRADE papers are designed for use with both diffuser and condenser enlargers. However, because of the different types of illumination there can be a contrast difference between the two types. In practical terms with most negatives, condenser enlargers give about an extra grade of contrast compared with a diffuser enlarger. This contrast difference, though, depends on the amount of silver left in the negative.

 

[Adrian Bacon]

From the Ilford Multigrade filter info sheet:
MULTIGRADE papers are designed for use with both diffuser and condenser enlargers. However, because of the different types of illumination there can be a contrast difference between the two types. In practical terms with most negatives, condenser enlargers give about an extra grade of contrast compared with a diffuser enlarger. This contrast difference, though, depends on the amount of silver left in the negative.

That’s about what I’m observing.

 

[ignatiu5]

An ND gel of your choice in the filter drawer.

I did what Pieter12 suggests, cutting, stacking and taping 1, 2, or 3 sheets of ND2 gel for my B22-XL. I can't recall how much change in contrast there was (if any), as I didn't print much without the gels. With them, I typically was using Ilford filters 2 or 3.

 

[Adrian Bacon]

I did what Pieter12 suggests, cutting, stacking and taping 1, 2, or 3 sheets of ND2 gel for my B22-XL. I can't recall how much change in contrast there was (if any), as I didn't print much without the gels. With them, I typically was using Ilford filters 2 or 3.

I doubt ND gels would have much effect on the contrast, as it’s not really diffusing the light.

This evening I experimented with a sheet of Duralar in the filter drawer and a circle of it sitting right on the top of the condenser, without the supplementary 35mm condenser. This made the vignette 2/10ths of a stop, so overall, very, very even, and with two sheets of diffusion with some air space between them, it’s about as diffuse as it’s going to get, so I’ll print the same test negative to see if there’s a contrast difference. The light level is also quite knocked down. I’m in the 15 lux range at f/2.8.

 

[Adrian Bacon]

Well, I will be a monkey's uncle....

I just did some test prints with a single sheet of 0.005 double sided matte Dura-Lar in the filter tray, and a single round 3.5 inch sheet of the same sitting directly on the condenser assembly without the optional 35mm lens assembly, and gained a full grade.

The image on the top left below is the print from the other night at grade 0.5 with only dura-lar in the filter tray. The image directly to the right of it is the same 0.5 grade (with exposure adjusted to produce the same black level as the first print). Clearly dark and low contrast. The right hand image below the top right image is the same print, but grade 1,0 (with the exposure adjusted to produce the same black level as the print on the left). The sky in the upper right part of the image is clearly darker than the sky in the top left image (meaning the total contrast is lower, because the black level is the same). The image on the bottom right is the same image, but grade 1.5 (with the exposure adjusted to produce the same black level as the top left image). The sky on the upper right is ever so slightly lighter than the sky on the image of the upper left, so it's just a smidge more global contrast, but close enough in practice it will make almost no difference.

I would say if you want to turn an Omega B-22 into a diffusion light source enlarger, remove the optional 35mm condenser lens, and put two sheets of matte-white duralar above the condenser unit, One in the filter tray, the other sitting on top of the condenser. It won't give a full grade, but it will be close enough. The paper used is Ilford MGiV Pearl. The black levels look a little different in the posted picture because I couldn't completely get rid of reflections from the room light and it's a crappy cell phone picture, however, the film base plus fog at each of those grades has an exposure that produces the same black level.

The bottom right picture also just looks better. It doesn't come out here, but sitting side by side, I very much prefer the way it looks over the image on the left.

Consider me happy.

 

[Paul Howell]

To convert to a true diffusion enlarger you need to get rid of the condenser altogether. Not sure about the B22, but with my D3 I can take out the bottom condensers leaving for lack a lack of better term the metal tube the condensers sit in and have sheet of opel glass cut to fit the tube. Again leave the adjustable top condenser out, but it will be slow. With only a small portion of the light actually hitting the negative, not too bad with 4X5, but once down to a 35mm need a stronger lamp. Color heads use halogen for a reason. I have a Omega cold light for the D5, I occasionally use it for 4X5, but really slow with 6X6 or 35mm. while myLPL with color head prints 35mm just as fast as the D5.

 

[Adrian Bacon]

To convert to a true diffusion enlarger you need to get rid of the condenser altogether. Not sure about the B22, but with my D3 I can take out the bottom condensers leaving for lack a lack of better term the metal tube the condensers sit in and have sheet of opel glass cut to fit the tube. Again leave the adjustable top condenser out, but it will be slow. With only a small portion of the light actually hitting the negative, not too bad with 4X5, but once down to a 35mm need a stronger lamp. Color heads use halogen for a reason. I have a Omega cold light for the D5, I occasionally use it for 4X5, but really slow with 6X6 or 35mm. while myLPL with color head prints 35mm just as fast as the D5.

I don’t doubt that no condenser glass at all is best, and I could do that, but would have have absolutely horrible fall off and vignetting without adding a lot more diffusion above the opal glass, or changing the light out to a significantly larger bulb, at which point, I might as well design or build a whole new lamphouse with maximum diffusion.

Having the two condenser lenses in the lamp house serves to magnify the light source, which smooths out the light spread, and while it is collimating the light that is reaching it from the focal point of the lenses (at the bulb location) there’s also effectively two other out of focus light sources in the optical path that are quite diffuse that aren’t really being collimated because they’re not in focus. Those other two light sources are bouncing around enough light to mostly negate the effects of the condenser in terms of contrast. Just having one diffuser doesn’t effect it much, but both together has quite an effect on the contrast.