Leitz V35 Autofocus?

[Alan9940]

About 20 or so years ago, I bought a used very complete V35 enlarger outfit; it came with the Focotar 2.8/40mm enlarging lens. However, if memory serves (dangerous territory there!) I replaced that lens with a Schneider APO-Componon HM 2.8/40mm because I determined that the Schneider lens was sharper than the Leitz optic. I probably didn't have the autofocus calibrated properly, but that was a long time ago. Anyway, a couple of questions:

1. If anybody has any opinion regarding the Schneider vs the Leitz lens (I still have it) with regard to sharpness, character, etc, I'd very much like to hear your thoughts. What say ye?

2. Is the autofocus on this enlarger based solely on the focal length of the enlarging lens? Being that the Schneider lens is the same focal length as the original lens, would the autofocus calibrate properly to this lens?

Thank you all for any insight provided.

 

[chip j]

One thing for sure--all the reviews I've read say that the Schneider APO is far superior to the Focotar.

 

[Alan9940]

One thing for sure--all the reviews I've read say that the Schneider APO is far superior to the Focotar.

Yeah, though my memory is vague I'm pretty sure my testing revealed that fact. Why else would I have stuck with the Schneider?

 

[AgX]

Enlarger manufacturers typically state that an Autofocus mechanism must be adjusted per sample of lens. In the case of the Focotar versus Componon even the nominal focal lengths may be different (40mm vs. 50mm) which means exchanging a cam anyway.

 

[Hilo]

(Also on dangerous territory): I would say the autofocus is based on the focal length and the physical measurements of the lens.

I use the Ic and when I exchange the Focotar for another 50mm lens, the auto focus is generally off. But never by much unless the construction of the lens is very different. In the end I don't care as long as I can get in focus. I always check focus with each negative, despite the autofocus. Standard procedure . . . .

 

[Rob Skeoch]

I own a V35 but have not tried the Schneider lens. I recently had my enlarger serviced because if was blowing fuses and the service person mentioned that the cams for AF were done on each enlarger/lens combo. So each enlarger was tweaked for the lens it was matched with. If I'm making a 8x10 size print and adjust the enlarger height to make a different crop, then I let the AF look after things. If I go from an 8x10 print and start to print 16x20 or larger, I refocus because the cost of the sheet of paper is worth more than the 10 seconds it takes to check focus.
The V35 is a great enlarger and a joy to work with. Sorry I have no knowledge of the Schneider lens you mentioned.

 

[AgX]

Even if two enlarging lenses of different manufacturers have the same focal length we do not know if the flange/focal-plane distance is the same for both models.

 

[Alan9940]

Thank you, all for your replies.

As AgX has intimated, I was pretty sure that factors other than the focal length of the lens would come into play when swapping out lenses. Really, all I'm looking for is for the autofocus system to maintain reasonable focus as I increase/decrease enlargement size (same as what Rob said.) I would always check critical focus with a grain magnifier before making any print. I think I'll just do the calibration routine and see how it goes. I've only owned 3 enlargers in my life--Durst F60, Beseler 4x5 MX and the Focomat V35--and, IMO, the V35 is absolutely superior for 35mm enlarging.

Thank you, again, for all your help!

 

[Randy Stewart]

The auto-focus 35mm enlargers, with one exception to my knowledge, come from the factory with a selected lens. The focusing cam is milled at the factory to exactly match the lens. All lenses of a stated focal length, Schneider, Nikon, Leitz, etc.,vary in focal length by very small amounts. This lens/cam matching was done so the user could have full confidence in the auto focus accuracy. The lens is usually locked into its mount with some sort of sealer so any later owner can tell if the lens or its adjustment has been upset. In the case of Durst (my preference) A300, each units has a plate on the column recording the serial numbers of the enlarger, the lens, and the negative carrier to insure that its integrity has not been compromised. The exception I first mentioned is the Durst AC800, which uses a mini-computer which allows the user to mount any lens of choice, then go through a process of exactly focusing the lens at a number of positions along the vertical column. This data is recorded and integrated to form a focus program for that lens, which is then used to position the lens focus at all points along the length of the column. More to the point, once you pull off the factory lens, your auto-focus accuracy is gone. Two lenses of same stated focal length will differ enough in actual focal length to make the autofocus system nonfunctional. Of course, it will still autofocus to an approximate focus which can then be tweeked manually into final focus. However, most autofocus enlargers are not set up to routinely focus manually, so overall, it would be more convenient to just skip a de-lensed AF enlarger in favor of a good manual unit, which should also cost much less. So, use your V35 as it came from the factory, or if you want to use a Componon, sell the V35 and buy something else. Putting the Componon on the V35 will significantly devalue the V35 and be a pain in the ass to use.

 

[Alan9940]

So, use your V35 as it came from the factory, or if you want to use a Componon, sell the V35 and buy something else. Putting the Componon on the V35 will significantly devalue the V35 and be a pain in the ass to use.

Actually, with some fiddling and multiple adjustments of the column I was able to get the autofocus to be darn close to perfect! Yes, I might have to tweak the focus ever so slightly, but I find that very easy to do at the typical enlargement sizes that I print to. I use the V35 because I think it's a precision instrument for the enlarging of 35mm negatives. My testing years ago, convinced me that the Schneider HM lens is visibly superior to the Leitz 40mm Focotar so I don't mind a little extra effort.

 

[emeraldcity_grain]

I own and use both lenses with my V35(s) for quite a while. Recalibrated the HM40 auto focuses perfectly fine. Albeit I tend to print only 2 sizes so one set up for a smaller print (Focotar 40) and the other set up for larger (HM40).
I find the optimum aperture for the Focotar to be at 5.6, while the HM at 8. Quite noticeable through my focuser.