Omega-D6 can't focus using a 50mm lens

[markrewald]

I have a D6 with a Chromega head. I have 2 lenes in the turrent. A 80mm and a 50mm. The 80mm is just fine. The 50mm can't focus. I can get it close but no cigar. I have the head extended as far as I can get it as well. Any thoughts? Oh I tried a different 50mm and it had the same issue.

I am almost thinking of bringing my besseler 23cii back into the darkroom just for printing 35mm negatives.

 

[MattKing]

Mark:

Which lens, and which lens plate?

Also, are you using the Omega masking attachment when you try to print from 35mm? I recently acquired a new Nikon 50mm lens for my D6, and found that the masking attachment raised the negative carrier too high above that lens' nodal point. With the masking attachment removed, it works great.

 

[Rick A]

You may need a recessed lensboard. Do you have the pro lab with bellows that covers 35mm through 4x5. I have one 50mm lens that barely focuses on the turret.

 

[akaa]

I have the Nikon 50/2.8 on the 3 lens turret and works great. I do know there were 2 different turrets available - maybe thats the issue?

 

[MattKing]

Here is the KHB memo on the two different types of turrets:

http://www.khbphotografix.com/omega/Discontinued/D6Turretmemo.htm

In case you don't have it, here is the KHB resource on lens, lens mount and lens plate compatibility:

http://www.khbphotografix.com/omega/LensMountD5.htm

 

[Ian C]

The Omega D5/D6 has long tapered bellows to accommodate 150mm lenses. That coupled with the small receiver for the slide-in lens plates makes it impossible to bring a 50mm lens close enough to focus an image large enough to make a borderless print larger than about 8” x 10” (some lenses can just barley make 11” x 14” due to a slightly longer flange-to-film distance ). Because the bellows are fully compressed the lens is simply too far from the negative.

The D5/D6 doesn’t have room to accept a recessed board to place a 50mm or shorter lens close enough to the negative to focus prints larger than about 8” x 10” or slightly larger with a reasonable amount of cropping ability.

It doesn’t matter whether the lens is mounted on a turret or is mounted onto a lens plate secured to the slide-in plate. Most 50mm lenses can be used on a D5 or a D6 to make an 8” x 10” print. Some might just barely make 11” x 14”, but with no cropping ability.

Whether using the correct turret or not, the essential problem remains: a 50mm or shorter lens is always too far from the film to focus beyond 8” x 10” or, in some cases 11” x 14”.

The D5 and D6 need a longer lens than 50mm in order to focus an image at any magnification allowed by the available negative-to-print distance and the minimum bellows when fully compressed.

You can use a longer lens than 50mm for enlarging 35mm films on a D5 or D6 or you choose a different enlarger that doesn’t have this design constraint.

 

[markrewald]

Thanks guys! Looks like I need to either take the D6 apart (which with my mechanical skills I will be sorry putting it back together) or bring back my Besseler. Dang. the darkroom is already VERY cramped.

 

[MattKing]

The Omega D5/D6 has long tapered bellows to accommodate 150mm lenses. That coupled with the small receiver for the slide-in lens plates makes it impossible to bring a 50mm lens close enough to focus an image large enough to make a borderless print larger than about 8” x 10” (some lenses can just barley make 11” x 14” due to a slightly longer flange-to-film distance ). Because the bellows are fully compressed the lens is simply too far from the negative.

Sorry Ian, but this is wrong.

I have no trouble doing 16x20 prints from 35mm negative with my D6 and either my older 50mm f/5.6 Rodagon lens or my newer 50mm f/2.8 Nikon lens - provided I have the correct lens mount and correct lens plate for the lens, and I remove the masking accessory.

Please note that there are some 50mm lenses that don't work with the D6, but as I understand it, that is due to the configuration of the back of the lens (it interferes with the mount).

 

[Luseboy]

why not just use the 80mm lens for 35mm? a lot of people choose to do this anyways...

 

[Neal]

Dear markrewald,

If you are having trouble focusing you might have the wrong mounting plate. Further, you should not have any trouble focusing unless you are over 16x20. Mine will give me a slight crop on a 16x20 before the bellows collapse entirely. There are no issues as you go smaller other than getting the head low enough.

Neal Wydra

 

[MattKing]

For perspective, here is a slightly blurry photo of three different lenses (including a 50mm) on three different lens plates on a D6 turret:


[url=http://www.flickr.com/photos/25623776@N00/5788503931/] lenses on Omega D6 3 lens turret by mlking, on Flickr[/URL]

 

[markrewald]

why not just use the 80mm lens for 35mm? a lot of people choose to do this anyways...

I have been using the 80mm but it crops way to much.

 

[Luseboy]

I have been using the 80mm but it crops way to much.

ah ok that makes sense then... well sounds like you probably need a recessed board... or would it be the opposite?

 

[Rick A]

Have you checked here for the proper mounting plate>
http://www.khbphotografix.com/omega/LensMountD5.htm
It should help you find what you need to correct the problem. If you need a newer style turret, contact me, I have an extra I can let go for a fair price or maybe even swap for something.