Wonky Chromega B?

Kino · Feb 20, 2006

Well, I got the ventilation in today and installed the wall mounted shelving that the enlarger sits upon, hung three graylab timers, and a brace of safelights, cleaned up the Jobo and put the Print dryer up on it's stand... almost ready to start printing!

I have a few of enlargers I have been hauling around for years, just for this moment; an ancient Omega B2, a Omega C760 dichroic, a Chromega B dichroic, a simple Unicolor 35mm enlarger and a Federal 470 "watermelon on a stick".

After placing the Chromega B dichroic on the table, dusting it off and playing with the controls, I flipped on the light and racked it up to see how high the head had to go with a 35mm neg carrier and a 50mm lens to get an 8 x 10 image and was shocked to find it went off the baseboard BEFORE it made the 8 x 10 size! That doesn't seem right...

I checked and made sure it was the right baseboard and it was. I checked the mounting on the column and it was fine and did not appear to be warped.

Am I nuts in thinking that this particular enlarger should make 8 x 10 native on the baseboard BEFORE running off the end of the baseboard toward the operator?

glennfromwy · Feb 20, 2006

That sure doesn't sound right. It's hard for me to give an answer without seeing it. All I can say is mine can make 11X14 easily and maybe 16X20 with no problem. It's got to be something in the mounting. How big is your base board?

AZLF · Feb 20, 2006

I don't know about the series Omega that you have but a few things occur to me.

On the D series in order to print 4x5 you must have the correct condenser ,lens(150-160mm) AND lens cone in order to get the right size within the elevation capabilities of the enlarger rails. When printing 35 mm you must remove the cone and use a flat lens board and a 50 mm lens and use the correct condenser. Or in the case of the D2V have the condenser lens in the right slot for the format.

Is it possible that you have some sort of "cone"(I.E. a mechanism that extends the distance between the film plane and the lens) assembly installed for medium format with the 50mm lens? This would give you the results you mention.

John Koehrer · Feb 21, 2006

Correct FL lens? (50mm for 35mm)

Kino · Feb 21, 2006

AZLF said:
(snip) Is it possible that you have some sort of "cone"(I.E. a mechanism that extends the distance between the film plane and the lens) assembly installed for medium format with the 50mm lens? This would give you the results you mention.

Ah, I bet that is it. I will check it when I get home; didn't think of the backfocus issue; I'll bet that the 2 1/4 lensboard is still in the unit. It came with both diffusers (35mm and 2 1/4) but only the 50mm lens... Bet the lensboard is a cone and not flat like it should be.

Doh.

The Chromega D is a diffusion enlarger, so condensers cannot be the culprit.

Thanks!

Kino · Feb 21, 2006

glennfromwy said:
That sure doesn't sound right. It's hard for me to give an answer without seeing it. All I can say is mine can make 11X14 easily and maybe 16X20 with no problem. It's got to be something in the mounting. How big is your base board?

Glenfromwy,

I will measure that when I get home, but I am pretty sure AZLF got it...

Kino · Feb 21, 2006

Hmm, I was wrong; there WAS a flat lens board on the Chromega B with the 50mm, it was the D760 that had a recessed lensboard that I was thinking of...

Glenfromwy, the baseboard is 19.5 inches deep and 16 inches wide; what are the dimensions of your baseboard?.

I went over the enlarger again very carefully and darned if I can find anything that would suggest it has been modified or put together incorrectly, so maybe the guy I bought it from had a non-standard baseboard.

Guess I'll have to build a wall bracket and side-step the issue!

AZLF · Feb 21, 2006

Perhaps I'm missing something really simple here but I fail to see how the size of the base board can alter the image size in any way. The length (height) of the rail attached to the base board with a given lens yes. But not just the base board alone. Too small a board could make it difficult to get the image size you wanted on the board but that is not what I thought was the problem. I understood the problem to be an image size at the full height of the rails that was not large enough(8x10").

Can someone splain' this to me.

Kino · Feb 21, 2006

It is not altering the image size at all.

What I mean is that by the time I enlarge an image to the size of 8x10, 35mm carrier and 50mm lens on flat lensboard, the image is spilling over the front edge of the baseboard and I am unable to place the easel on the baseboard without it falling off.

I now think it *is* a case of being a non-standard baseboard...

AZLF · Feb 21, 2006

Ohhhhhhhhhhhhhh....

Okay.
never mind.

David Brown · Feb 21, 2006

OK. Is it a B or a D?They're very different.

Kino · Feb 21, 2006

The enlarger in question is the Chromega B.

David Brown · Feb 21, 2006

Kino said:
The enlarger in question is the Chromega B.

OK, good. I have both the Chromega B and a B22. (and a "D", but let's leave that out of this )

They are essentially the same machine - one with a condensor head and one with the dicroic. Now, the Chromega B's were sold with different columns and baseboards. The ones with shorter columns usually had the 19.5" baseboard, but the later ones and ones with a taller column have a 26" baseboard. I have both.

Since you said that your baseboard is 19.5, I just went and put the 35mm carrier in the B22 (with the 19 incher), mounted the 50mm lens, and got a sharp outline of the carrier at 8X11 inches with the head up so that the negative stage was about 20-21 inches above the baseboard.

The image was right up to the edge of the baseboard, however!!

If you have a very big easel, it may indeed hang over the edge.

I know this doesn't solve your problem, but it may take some of the mystery out. The 19 inch baseboard is too short, and they (Omega) changed that in later models. Make a new baseboard, or mount the thing directly to the counter top.

Good luck.

David

glennfromwy · Feb 21, 2006

I think the baseboard is the whole problem. Mine is homemade but about 26 inches or a little more deep.

Wonky Chromega B?

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