New lensboard for an old enlarger

[Joao]

Hello
I have an old Durst 606 and I was looking for a specific M39 lensboard for it. The original aluminium alloy models are scarce and very expensive, so I've ordered a brass disk with the exact diameter and a M39 thread. The M39 lenses (Rogonar Rodenstock) fit quite well. My questions are:
1 - Should I worry with the thermal dilatation of the board - brass and aluminiun have different dilatation coefficients...
2- The original boards are more or less recessed; in the photo there is a very recessed original board (top) for a M 25 lens and a slightly recessed board (M 39, but for a different Durst model) middle. The brass lensboard is the lower one and is completely flat. Will this flateness affect the printing ??
3-Any benefit to be expected if I paint the brass with a heat-proof paint ?
Thank you for your opinions.
Joao

 

[Roger Hicks]

Hello
I have an old Durst 606 and I was looking for a specific M39 lensboard for it. The original aluminium alloy models are scarce and very expensive, so I've ordered a brass disk with the exact diameter and a M39 thread. The M39 lenses (Rogonar Rodenstock) fit quite well. My questions are:
1 - Should I worry with the thermal dilatation of the board - brass and aluminiun have different dilatation coefficients...
2- The original boards are more or less recessed; in the photo there is a very recessed original board (top) for a M 25 lens and a slightly recessed board (M 39, but for a different Durst model) middle. The brass lensboard is the lower one and is completely flat. Will this flateness affect the printing ??
3-Any benefit to be expected if I paint the brass with a heat-proof paint ?
Thank you for your opinions.
Joao

1 No.

2 The recess may be necessary for big enlargements (lens closer to film)

3 Can't hurt. No disadvantages that I can think of and reduced risk of reflection if you paint the side facing the film, using matte paint. Painting the other side will improve heat dissipation. Needn't even be that heat-proof: how hot does it get, after all?

You do know, incidentally, that Leica screw thread is 39mm x 26 tpi, not 39x1mm?

Cheers,

R.

 

[Joao]

Roger
Thank you for your reassuring reply.
I am not intending to start with large prints so I will forget the recessed boards for a while.
Regards
Joao

 

[sevo]

Hello
I have an old Durst 606 and I was looking for a specific M39 lensboard for it. The original aluminium alloy models are scarce and very expensive

Durst had quite a huge variety of lens boards, for only three or four different diameters, and the 606 takes the smaller of the two most common sizes. There also were original plastics and stamped metal ones that fit - you do not need the machined ones. And even the latter frequently show up dirt cheap, if you just have some patience and stay away from professional "buy it now" fixed price dealers. I don't think I paid more than 10€ for any of the Laborator lens boards I bought on ebay in recent years.

 

[Joao]

Sevo
I have been looking for the appropriate Durst 606 lensboard (Sixpla, Ixopla or some other strange name ending in "pla" - the Durst glossary is really hermetic) for a long time, and did not found anything suitable & inexpensive.
The board you see in the middle is too small for the 606; the board I was looking for is larger (8.2 cm diameter). I had this one made in brass for less than 10 euros - I should have made this option earlier...
Regards
Joao

 

[sevo]

Very odd. Sure they are 82mm in size, not 78mm?

The mainstream Durst lens board size, used on most of their medium to large format enlargers would be round, 78mm in diameter. The Durst nomenclature is a mess, and generated names of several hundred lens boards, for what essentially were only a few dozen different boards (of whom the majority will only fit some very special accessories to very professional enlargers/printers). Apart from these exceptions that attach to their professional printers and a few plastics items for entry level 35mm only enlargers, they essentially had one size, three materials (plastics, cast/machined aluminium and stamped steel), in both flat and recessed (the latter in multiple sizes). But as they used a different letter code for each enlarger group even though the boards were the same, the list is about eight times as long as it would have needed to be.

Going by the manual, the 606 uses IXO... designated boards. As there are several people on the net that claim using IXO... boards on the M605 or M805 (whose native designation was SIRIO...), and I can use my Laborator 1200 (LA...) boards as well as the original SIRIO... series on the M805, I would have thought the IXO... series to be be 78mm as well. About the only explanation for that (short of one or other side being plain wrong) would be if some M605's were supplied with a 606 backward compatible front panel.

 

[Joao]

Very odd. Sure they are 82mm in size, not 78mm?

The mainstream Durst lens board size, used on most of their medium to large format enlargers would be round, 78mm in diameter. The Durst nomenclature is a mess, and generated names of several hundred lens boards, for what essentially were only a few dozen different boards (of whom the majority will only fit some very special accessories to very professional enlargers/printers). Apart from these exceptions that attach to their professional printers and a few plastics items for entry level 35mm only enlargers, they essentially had one size, three materials (plastics, cast/machined aluminium and stamped steel), in both flat and recessed (the latter in multiple sizes). But as they used a different letter code for each enlarger group even though the boards were the same, the list is about eight times as long as it would have needed to be.

Going by the manual, the 606 uses IXO... designated boards. As there are several people on the net that claim using IXO... boards on the M605 or M805 (whose native designation was SIRIO...), and I can use my Laborator 1200 (LA...) boards as well as the original SIRIO... series on the M805, I would have thought the IXO... series to be be 78mm as well. About the only explanation for that (short of one or other side being plain wrong) would be if some M605's were supplied with a 606 backward compatible front panel.

Sevo
I am not at home and I have no caliper to make an accurate measurement but with a plain ruler I can say that it measures more than 78 mm - it could be 81 mm if my measurement is not precise. It was made according to the diameter of the original more recessed board (top, in the photo of the OP)
Anyway, I tested this machined brass board in the enlarger and it fits quite well. Maybe a 78 mm board would probably also fit as the screw that holds the board is several mm long and thus could hold the board in place.
I will put the enlarger at work and see what happens
Regards
Joao

 

[Nokton48]

Durst Pecessed Lensboard on a Plaubel Makiflex.

Durst Pecessed Lensboard on a Plaubel Makiflex.

These boards are also useful too me. I use them to recess old Schneider barrel-mounted lenses, so I can put them on my three Plaubel Makiflexes.

Here is a 135mm f4.5 barrel-mounted Xenar, mounted on the Durst IXTUB.

 

[sevo]

Here is a 135mm f4.5 barrel-mounted Xenar, mounted on the Durst IXTUB.

Can you measure its diameter?

 

[Nokton48]

Can you measure its diameter?

Hi Sevo,

Sure, no problem. Inside diameter is 66mm across at the front of the IXTUB. Will also focus my 120mm barrel-mounted Rodenstock Imagon from infinity to closeups. And works with both models of the Makiflex. I have three or four of these boards, they are quite useful.

-Dan