Durst Tripla

[scott palmer]

I have a Durst 138 that has a Tripla turret lens holder. It limits the lenses I can use. Is there a way to convert it to a single lens board system? Would I have to machine/fabricate a base plate the same diameter as the Tripla? Thanks ahead of time.

[Drew Wiley]

Yes, the Tripla can easily be removed via the screw in the front. You can replace it with a Unipla, which would have to be drilled for your specific lens barrel size.
These are quite difficult to find nowadays. Someone has been offering 3d printed plastic ones on EBay; I can't vouch for how flat or rigid they remain. Glenn Evans (Glennview.com) can make a real aluminum plate version, bored and threaded, and have it black anodized. I machined my own out of thick black Garolite phenolic board, which is quite strong but not entirely dimensionally stable (I normally use the standard Durst Tripla). I simply had a lot of scraps of Garolite lying around from a former project, and the correct pricey carbide.

The boards should be the same diameter, with the same compound edge bevel.

[ic-racer]

What lens do you want to use that won't fit the 138's Tripla? I even have lenses for 8x10 on mine.

251609

[Drew Wiley]

A 360/9 Apo Nikkor will fit in a Tripla ring; but a faster 360/5.6 El Nikkor is too big for even a Sinar board adapter without special adaptation (yeah, I do have one 8x10 enlarger which uses Sinar boards). 360's are not typically used on a 138 chassis; but the Tripla/Unipla system is also used on the bigger 184 chassis. 138's can also be modified to accept 8X10 carriers. The fact the Unipla board is still in demand tells you that some people are using big diameter lenses, often process lenses, or else they might have some other reason to want only a center hole.

[interneg]

Some generations of the 138s have built-in TRIPLA boards, the later ones don't (in those cases, as described above, the TRIPLA is essentially just a lensboard adapter in a UNIPLA fitting). If the lens is too big to go in a TRIPLA, it's excessive for 5x7.

[Drew Wiley]

The most coveted enlarging lens for 5x7, the 210/5.6 Apo El Nikkor, is too big a diameter for the Tripla. But most of us could never afford one of those, or else regarded it as overkill. I do just fine with either a 180/5.6 Rodagon for 5X7, or else the 240/9 Apo Nikkor. (The ordinary El Nikkor 240/5.6 won't fit; the 210/5.6 El Nikkor will). I personally prefer working with longer than "normal" enlarging lenses whenever logistically realistic.

[notorius]

I have 240/5.6 Componon(not S) and it fits the Tripla in the 138S. It should cover up to 8x10.

[Drew Wiley]

The 240/5.6 Rodagon also fits; it's often used for 8x10 enlargements. I can use the 240/9 Apo Nikkor for 8x10, although it doesn't attain fully even illumination with that format unless stopped down to f/16 in conjunction with my Durst 12X12 mirror box. Longer focal lengths will achieve it at f/11.