Omega D2 question

PhotoPete · Jul 31, 2006

I am going to post my question here, before I go over to classic enlargers and ask Harry.
I have an Omega D2 with the variable upper condenser, which I believe makes it a D2V. I recently fiddled with the bellows adjustment that controls the distance between the neg stage and the lensboard. This caused some vignetting when printing 4x5 with the 135 mm lens, which I have resolved by removing the upper condenser as you would with a 150 mm lens. My question is twofold:

1. What the heck is the name of that adjustment and control (it even has a scale)?

2. How do I dermine what value on the scale should be set to for any given situation? I suspect it is some combination of neg size, focal length and enlargement factor.

Thanks in advance.

Will S · Jul 31, 2006

You are using a cone with the 135mm lens right? I forget the size, but I think it is 3" or so. There are shorter and longer cones for different focal lengths.

Thanks,

Will

Bob Carnie · Jul 31, 2006

I call it the lens bellows adjuster.
It has a different setting for each lens. totally to the top for 35mm and down to the bottom for 150mm.
I am suprised that with a 135mm lens you need to remove the condensor from the upper position.
Are you sure the problem is not wrong positioning of the negative in the carrier?

question two

35mm neg- condensor bottom position -lens bellows all the way to the top.
6x6mm negative - condensor middle position - lens bellow mid point
4x5 inch negative - condensor top position or out - lens bellow bottom point.

PhotoPete said:
I am going to post my question here, before I go over to classic enlargers and ask Harry.
I have an Omega D2 with the variable upper condenser, which I believe makes it a D2V. I recently fiddled with the bellows adjustment that controls the distance between the neg stage and the lensboard. This caused some vignetting when printing 4x5 with the 135 mm lens, which I have resolved by removing the upper condenser as you would with a 150 mm lens. My question is twofold:

1. What the heck is the name of that adjustment and control (it even has a scale)?

2. How do I dermine what value on the scale should be set to for any given situation? I suspect it is some combination of neg size, focal length and enlargement factor.

Thanks in advance.

PhotoPete · Jul 31, 2006

Bob Carnie said:
I am suprised that with a 135mm lens you need to remove the condensor from the upper position.
Are you sure the problem is not wrong positioning of the negative in the carrier?

I never had a problem until I messed with the bellows position- previously, I could print just fine with the 135 and the condenser placed per the instructions. I moved the carrier and the neg all around, so I knew that it was not the source of the problem.

Bob Carnie · Jul 31, 2006

Here is what I would do

Go to your normal set up , if you are still getting vignetting , move the bellows up and down and watch what happens on the easel , also move the rough focus knob up and down. The bellows should be somewhere in the middle position. If the bulb, negative, lens and easal are all in synch you should not be having any problem whatsoever.
I move this bellows all the time and in fact it is in different positions all the time depending on how much I am focusing . there is a rough focus knob and a fine focus knob on most of my Omegas.
It may also be that you have racked out the focus too much and when you position the bellows you are not in a good focus to bellows position for a 135mm lens.

Wish I could help you more

dancqu · Jul 31, 2006

PhotoPete said:
I recently fiddled with the bellows adjustment that
controls the distance between the neg stage and the
lensboard. This caused some vignetting when printing
4x5 with the 135 mm lens, ...

Fiddled? A few years have passed since I last checked
for condenser focal length. Of course once it's set it stays.
IIRC, I removed the lens with board then measured the
distance from the bottom surface of the bottom
condenser to the focal point of the light bulb.
That's what the condensers do, focus the
light from the bulb.

As I recall the lens at it's likely greatest extension is to fall
within the focal length of the condensers. If you need
more light for small negatives the light from the bulb
is made more condensed; focused more near the
negative stage.

There's nothing to making the condenser measurements.
Check for other combinations while you're at it. Dan

PatTrent · Jul 31, 2006

Here's what my D2V instruction book says:

162mm-150mm lens: Remove the variable condenser (which they also refer to as the "auxiliary lens) entirely

135mm lens: The variable condenser goes in Position 1 (top position)

105mm-90mm lens: The variable condenser goes in Position 2 (middle position)

80mm-50mm lens: The variable condenser goes in Position 3 (bottom position)

Will S · Aug 1, 2006

I guess my D2V does not have one of these "lens bellow adjustment" thingies, which is why I need cones. Is it possible to buy these? Of course, I have all of the cones already...

Thanks,

Will

PhotoPete · Aug 1, 2006

After closer inspection of the Omega pictures on www.khbphotografix.com, I don't have a D-2 after all. It's a D-5, without the XL column.

Photo Engineer · Aug 1, 2006

The cone for the D2V / 135mm lens is 4.5 " measured from mount to mount.

PE

r-brian · Aug 1, 2006

KHB lists the 4 1/2" cone for 150mm - 162mm lenses, the 2 3/4" cone for 105mm - 135mm lenses. Does this change if you convert to a variable condenser head?

I converted my DII to a variable condenser head and I am getting the same vignetting problems discussed here when using my 135mm Rodagon on the 2 3/4" cone with the moveable condenser in the upper position, which is for 135mm lenses.

Brian

Photo Engineer · Aug 1, 2006

r-brian said:
KHB lists the 4 1/2" cone for 150mm - 162mm lenses, the 2 3/4" cone for 105mm - 135mm lenses. Does this change if you convert to a variable condenser head?

I converted my DII to a variable condenser head and I am getting the same vignetting problems discussed here when using my 135mm Rodagon on the 2 3/4" cone with the moveable condenser in the upper position, which is for 135mm lenses.

Brian

I've used the 4.5" cone with my D2V for nearly 20 years with a 135mm lens, and about 15 years ago converted to the Beseler Dichro 4x5 head eliminating the condenser. I still use the same cone with the same lack of vignetting.

I use a 2.75" cone with my 105 - 150 mm zoom lens with good results too.

PE

PatTrent · Aug 1, 2006

r-brian said:
KHB lists the 4 1/2" cone for 150mm - 162mm lenses, the 2 3/4" cone for 105mm - 135mm lenses. Does this change if you convert to a variable condenser head?

I converted my DII to a variable condenser head and I am getting the same vignetting problems discussed here when using my 135mm Rodagon on the 2 3/4" cone with the moveable condenser in the upper position, which is for 135mm lenses.

Brian

I use the 4-1/2" cone with the 150mm lens in a D2V (variable condenser) head. The adjustable/variable section of the condenser is completely removed in this case.

Omega D2 question

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