Question for those who know the beseler 8x10 conversion and lenses for it.

[bobbysandstrom]

My conversion is on a mcrx and it will be here soon. I'm not sure about lens coverage and compatibility. As you might have seen on another thread the issue of falloff/sharpness came into being when talking about a 240. My question is:

Can I put a 300mm lens on that conversion/enlarger combo? And, what is the BEST lens re sharpness and eveness for that combo.

Thanks for your help.

b0b

 

[df cardwell]

bob

why not just get hold of alan ross ?

 

[bobbysandstrom]

df

I did and he said the 240 would work! I hadn't asked him about a 300. I think he has a different (bigger) enlarger than the mcrx which gives him different choices.

Thanks

 

[df cardwell]

cool: you'll have a great time with the Beseler.

If you outgrow it, there will interesting choices. In the meantime, you'll make a lot of cool pictures.

You might use some N.D. filtration for those itty bitty 11x14s...

d

 

[Donald Miller]

Howard Bond also used a Bessler 8X10 conversion the last that I knew. I don't recall what lens he uses.

 

[AllenR]

Bob,

Since you are stuck with a 4" lens board on the MCRX, something like a 240 f/5.6 El Nikkor or 300 f/5.6 Rodagon cannot be mounted without machining some sort of adapter. There are two issue here. First, the mounting flanges on some of these faster lenses are greater than 4" in diameter. Second, the rear element can be larger in diameter than the opening in the lens stage on the MCRX and may protrude too far. Either way, some sort of custom mount would need to be built and even at that it would be a compromise. Weight is also a consideration. As I've said before, the MCRX chassis was never really designed to hang that much weight that far out from the upright. Adding a fast, heavy, long focal length lens on some sort of adapter is only going to add to the problem.

Longer focal length F/9 optics are easily mounted on the 4" boards, but you have to deal with a dim image for focusing. As for sharpness, any of the modern optics will provide similar performance as long as they provide sufficient negative coverage.

Allen

 

[bobbysandstrom]

Allen, thanks for your earlier pm regarding this. I can tell you that the transformer has been removed from the head thereby making it lighter (so I'm told) and less prone to vibration etc. I don't mind focusing at f/9 so as long as I get proper coverage from a 240 I'm good to go!

bob

 

[AllenR]

Bob,

The transformer is separate from my head too, but it is still plenty heavy. The 240mm F/9 Beslar HD is a decent lens if you can find a good used one. I believe that it is really a Rodenstock.

Allen

 

[bobbysandstrom]

Allen: what about a 210 el nikkor. Any comments? I only want to go up to 16x20 max.

Thanks again

 

[AllenR]

Bob,

I was under the impression that the 210 El Nikkor only covers 5x7. I've never used one, so I can't say for sure. Maybe someone else has experience with that lens.

Allen

 

[Loose Gravel]

The 210 El Nikkor works with 8x10. Covers fine on small prints (810 and 1114). The ring that holds it to the lensboard must be filed on 2 sides so that it can be fitted into the lens stage. Not a big deal.

I didn't like the way the enlarger bobbed around with the 810 conversion, so I've added some wall support. Seems fine now. Some people add counter-balance to help the motor and existing counter-balance a bit.