Omega C700 vs. Beseler 23C II dichroic vs. Omega D2
I have an enlarger conundrum. I keep picking them up for free or nearly so.
First of all I am an apartment dweller and my darkroom is in a closet. It works, though, and I have my Omega Concept 6 enlarger (similar to C700) and 35mm and 6x6 negative carriers wedged in there. It works, and the paper safe is quite convenient.
Well now I got this 23C II with dichroic head and Omega D2 enlarger from a photo club that disbanded and left all their stuff in some guy's garage. No lenses or negative carriers, and I think the Omega is missing the bellows that goes between the giant condenser lens and the carrier stage. Are these enlargers any good? I don't understand what the upper bellows adjustment is for on the Beseler, and the lensboard is not threaded, making it really inconvenient to change lenses...do you really have to use a screwdriver to change lenses?
Well I don't know what to do with them. The Beseler looks cool because it does larger medium-formats (which I don't shoot right now). It also has a color head (although I don't have a real problem with using multigrade filters and don't currently print color, but might try it). But it won't do 4x5 (which I can see taking up in the future) without modding. I originally thought I would replace my concept-6 with it, since it does everything it does and more. I just don't think it will fit in my closet, and I don't have negative carriers for it, and I don't really have a need for it right now.
The Omega D2 does 4x5 but that's it. I can't see using it for anything else. But unless I mod the 23C, it would be my ticket to large format.
I guess I could move my darkroom out of the closet (feasable but encroches on the rest of my man-space), in which case I could bolt all 3 of them to my work bench. But it seems like I should just pick one.
Personally, I'd take the D2. I've used both the beseler 23c and the omega D2. As far as I know, there's no bellows between the condenser and the negative stage. If it looks like there's loose space there it's probably because you need to put a negative carrier in there. When I was looking for an enlarger I'd been searching for a D2, but in frustration I ended up getting an Omega B-8, which is more or less a slightly smaller version of the latter. It's probably easier to get a color head for the omega than to convert the beseler to 4x5. The D2 with a color head would be a wonderful enlarger, imo. I so very nearly obtained such a machine but the amount of magical green paper I had at the time held me back.
It's worth mentioning that I have found that I do have 35mm and 4x5 negative carriers for the D2, which is actually a D II. I guess there is a difference between a D2 and DII.
What's the upper bellows adjustment for on the 23C? I know the bottom bellows focuses, but does the top just adjust brightness? I found out that you can take the lens board out without using a screwdriver.
The D II can do everything between 16mm and 4x5 - as long as you have the right negative carriers, lensboards and condensors.
The Beseler will do everything between 16mm and 6x9cm - as long as you have the right negative carriers. In most cases, you won't need different lensboards, as long as your lenses have the same thread sizes. The condensors that come with a condensor head should handle all those sizes, as long as you adjust that upper bellows appropriately.
You cannot really modify a Beseler 23 series enlarger to use 4x5.
Accessories and parts for both the Beseler and the Omega DII should be relatively easy to find.
I just went from a Beseler 67 series enlarger (with both condensor and colour heads) to an Omega D5 (with both multigrade and condensor heads), but I'm keeping my Beseler enlarger in storage, because if I can ever move again to a dedicated darkroom, I'll use both.
In your case, I'd keep using the C700 for now, but keep and store one of the others, until you can either figure out how to use it in your smaller space, or get a bigger space.
The upper bellow allows you to change formats without changing condensers> There should be a guide that show the position for each negative size on the right hand side just behind the head.
Heavily sedated for your protection.
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The upper bellows in a condensor enlarger is used to focus the light source into the enlarging lens pupil. In a condensor enlarger, the light source is formed into an image by the condensors and this image should be located at the diaphragm in the enlarging lens. The upper bellows adjustment is used to move the light source image to the proper position in the enlarging lens, hence the markings that show various film (lens) sizes for its position. The light source isn't a true point source, so its image formed by the condensors isn't precise. The light cone produced by the condensors must be matched with the light cone of the enlarging lens to achieve uniform illumination.
If you replace the condensor with a diffusion box--one option for the 23C then the light source is not imaged and there is no longer any need to adujst the upper bellows. In this case you simply elevate the light source to fill the diffuser.
Condensor enlargers produce the maximum detail owing to their "high contrast" illumination. Diffusion enlargers are softer and more forgiving of film plane defects--scratches, dust, grain, etc. Many people don't like the rather extreme sharpness of the condensor illumination, while it is preferred by others, especially for black and white work.
You cannot modify a 23C for 4x5 because the condensors or the diffusion box diameter is too small to cover the film size. Also, the longer focal length of the 4x5 lenses (135 mm is typical) will not focus because the enlarging lens bellows has insufficient length. Note that when changing lenses, you normally replace the lensboard and lens as a unit. It's not necessary to remove the lens from the lensboard. Lenses either thread into the lensboard or are retained on the board by a "jam" nut.
I recently modified my 23C II for 3 1/4 x 4 1/4 as follows:
1. Buy a spare film holder from e-Bay. Drill out the rivets that hold the circular alignment ring and then mill out the film opening for 3 x 4" allowing for 1/8" all around to hold the film. When used in diffusion mode, the illumination circle will cover all but the corners of the 3x4 opening.
2. Obtain a 4x5 enlarging lens and a couple of 4" square lensboards (or make the boards from 1/8" plate). Obtain ~3-4" of 3" PVC pipe to make a lens mount extension.
3. In the lathe, square up the PVC pipe ends and cut it off to 2 1/2" length.
4. Configure one of the lensboards to accept the 135 mm enlarging lens either with a jam nut or by mounting an appropriate adapter to it.
5a. Mount one of the lensboards in the lathe and bore the center to accept the PVC o.d. (about 3.54") with a press-fit. Epoxy the PVC pipe into the bore opening.
5b. Mount the other lensboard in the lathe and turn off the square to the diameter of the PVC pipe i.d. (~3.040") for a press-fit into the PVC pipe.
6. Blacken the entire assembly with flat-black paint and/or black flocking on the inside of the PVC pipe extension. Install the enlarging lens into the lensboard.
7. The entire lens-extension assembly mounts as does any other lens into the square spring-loaded lens frame. The extra 2 1/2" length allows the 135 mm lens to focus and it covers all but
the corners of the 3x4" film.
That's about all you can do for a 23C enlarger. You cannot get any more coverage than the diameter of the illumination circle. If you want 4x5 then you have to move up to a much larger unit and that means a lot bigger space.
By denying the facts, any paradox can be sustained--Galileo
Keep the 23C, this is a solid enlarger. Sell the Omega and when you go to 4x5, get a Beseler 45. If you keep both Beselers, the lens boards are interchangeable.
The only Omega I have first hand experience with is the C67. Not very impressive.
I've seen in done online; using an Omega 4x5 negative carrier, the modder just enlarged the negative stage to cover the opening in the negative carrier, and then made a simple diffusion light source using LED. It's true that the stock light head would probably not cover 4x5.
You cannot modify a 23C for 4x5 because the condensors or the diffusion box diameter is too small to cover the film size. Also, the longer focal length of the 4x5 lenses (135 mm is typical) will not focus because the enlarging lens bellows has insufficient length.
Last edited by BetterSense; 06-20-2009 at 06:49 PM. Click to view previous post history.
f/22 and be there.
Well, here's the way I see it. The Omega D2 (or D II) is a fine enlarger. Heavy, and stable, but large; it will handle anything from a subminiature negative to a full 4x5. I use a D4 myself, which is at its core, a beefed up D II with autofocus and have no complaints with it. It is sturdy and does what I need it to do. If you plan to ever shoot 4x5, this is the machine you want to keep. Modifying a smaller enlarger to do the work will be problematic at best, and an unmitigated disaster at worst. The D II will do it all without raising a sweat. All you need are the correct, and reasonably easy to find, accessories and you're good to go.
I have a question about the dichro head on the Beseler.
It has two cords, a grey one and a black one. The instructions say that one of them gets plugged into the wall and another gets plugged into the timer. Does this mean that the bulb stays on all the time, and the timer just opens a shutter or something? Because it gets very very hot in my darkroom as it is. There's no way I would be able to use an enlarger that was on constantly.