Cannot focus Componon-S 50mm mounted on Opemus 5 !

[mr.datsun]

Here's the scene:

Meopta Opemus 5. 39mm mount board.

add Componon-S 80mm – can focus.

add Componon-S 50mm - cannot focus.

I can only get the 50mm to focus when the enlarger head is as near to the base board as possible and the enlargement factor is around 1:1.

At any other height the bellows needs to be wound tightly up to go any where near an image being apparent but completely out of focus.

Mystified by this. Same mount being used in both cases.

 

[Ken Nadvornick]

Seems that your bellows compression will not allow the lens to be physically close enough to the negative plane to achieve focus. Can you use a recessed lens board with that enlarger? Or if the lenboard you have at all pushes the lens away from the negative plane, even a little bit, can you use that lensboard reversed?

What you describe is not an uncommon problem with 50mm enlarging lenses, depending on your enlarger. Here's a photo.net thread describing the same problem with a Beseler 45MXT enlarger. The first reply sums it up...

Ken

 

[tony lockerbie]

Simply the lens is too far from the film plane. I had the opposite problem with a 63mm Nikkor on a Leica 1C, eventually found an extension tube that fixed the problem. You need to recess the lens somehow, don't know if that's possible with your enlarger. I think that the Opemus V was designed for 6x6 (75 - 80 mm lens) so there isn't enough compression for that short focal length.

Tony

 

[ath]

Reverse the lensboard.

 

[mr.datsun]

Thank-you for your replies! I looked at the manual and indeed I found that the lens-board needs to go the other way up. Stupid of me to assume it protruded downwards.

The only trouble now is that it is not designed for the Componon-S with it's side arm which stops it screwing in very tightly and stops the arm being used to stop down. Still it just works.

 

[Ken Nadvornick]

Not a stupid assumption at all. Sometimes the opposite of a recessed board is necessary. I have an Omega D5XL with the three lens turrent. One of my lenses is the older-style Schneider 100mm f/5.6 Componon-S. It has a rear element that protrudes sufficiently such that an extended lensboard is needed to allow the turret to rotate freely. Focus is achieved by simply racking the bellows a bit higher. It all depends on your particular enlarger hardware limitations.

If your 50mm won't fit into the recessed board, perhaps you could trade it for an earlier Componon-S without the arm? I prefer this type myself and use a matched set of 50, 100, and 150mm Componon-S samples from the mid-80s. None of them have arms. (Or those annoying lighted aperture scales.)

Or maybe you could even find a way to shift the bellows upward just enough to bring the lens closer to the negative? I'm not familiar with your enlarger, but perhaps it's worth a look?

Ken

 

[mr.datsun]

Not a stupid assumption at all. Sometimes the opposite of a recessed board is necessary. I have an Omega D5XL with the three lens turrent. One of my lenses is the older-style Schneider 100mm f/5.6 Componon-S. It has a rear element that protrudes sufficiently such that an extended lensboard is needed to allow the turret to rotate freely. Focus is achieved by simply racking the bellows a bit higher. It all depends on your particular enlarger hardware limitations.

If your 50mm won't fit into the recessed board, perhaps you could trade it for an earlier Componon-S without the arm? I prefer this type myself and use a matched set of 50, 100, and 150mm Componon-S samples from the mid-80s. None of them have arms. (Or those annoying lighted aperture scales.)

Or maybe you could even find a way to shift the bellows upward just enough to bring the lens closer to the negative? I'm not familiar with your enlarger, but perhaps it's worth a look?

Ken

Ken,
The difference between the two flipped orientations is around 1 & 1/4" as the height of the recessed lens-board is 5/8s". The focus is very far out and the bellows are jammed together with no sign of focus being achieved. I can't see a way around that one.

With regards the lenses. I just spent what seemed like ages getting these two lenses but it is an option. But I have now identified a new problem with the Opemus 5 – the head ratchet mechanism slides during exposure! I can see the head visibly creeping down as I watch, with no sign that tightening the screws fixes it. I'm beginning to think that the £20 I spent on the enlarger is worth writing off and looking for a better one.

Thanks

D

 

[mr.datsun]

If your 50mm won't fit into the recessed board, perhaps you could trade it for an earlier Componon-S without the arm? I prefer this type myself and use a matched set of 50, 100, and 150mm Componon-S samples from the mid-80s. None of them have arms. (Or those annoying lighted aperture scales.)

As an update for reference. I have removed the arms from both lenses. They unscrew and the small screw can be put back in for safe-keeping and also I think it will still operate as a quick stop-down mechanism but less obtrusive. I'm hoping that means the lens can now fit properly (when I try it later).