Enlarger Lens Size For 8x10 ?
I just received a shipment of items that I purchased from Francesco.
(Thanks Francesco, the items are just as described)
Included in the lot was a Mint Componon-S 240mm Lens.
I know that the Componon-S lenses are excellent quality (that's what I use) but I'm not sure what size is "normal" for 8x10.
Is the 240mm good for 8x10, or would it be like using a 135mm for 4x5 (I use a 150mm for 4x5)?
I'm using a 210mm El Nikor for my 810 enlarger. Usually use 150mm for 45, but if I need bigger enlargement, I use the 135mm. Works fine and I think a 240mm will work for you.
I haven't used a Componon-S 240mm lens, but I have used both 240mm and 300mm El Nikkor lenses with 8x10 and a 300mm Rodenstock Rodagon (I have also tried a 240mm Rodenstock Apo-Geronar, this is a process lens that Besler sold with their own label as an 8x10 enlarging lens--it's very nice for 5x7, but doesn't really cover 8x10). The two 300mm lenses seem pretty equivalent to me in sharpness. The Nikkor is nicer to use, but is too big for my current 8x10 enlarger, it easily fit on an old Elwood I used to own.
When I got the 240mm El Nikkor lens, I did some comparison prints between the two El Nikkor. I did one comparison at a 30x40 print size (actually just some 8x10 paper in the center and corner of the image) and one smaller size (either 11x14 or 16x20, can't remember). All the differences were pretty minor and only really visible when comparing the prints side by side. In the center, the 240mm lens was slightly sharper at both maginifications. In the corner, the 240mm lens was sharper in the smaller print and the 300mm lens was sharper in the larger print. I took this to mean that the 240mm lens was a slightly sharper lens overall but had a smaller image circle. For smaller prints you have more bellows extension so you need less coverage. For big prints, you need more coverage. Since getting the 240mm, I haven't used the 300mm, but rarely print larger than 16x20. If I were doing a 30x40 print, I'd still probably use the 240mm since the working distance is much more convient and the sharpness difference is very small.
In theory, the 300mm should have less light fall-off, but I have found that this is more of a function of the size of the light source. I can't tell the difference with my two lenses with either 8x10 enlarger I've used (a De Vere with a color head or an Elwood with a 12x12 cold light). If the light source is barely large enough, using a longer lens will help with corner illumination. If the light source is oversized, a shorter lens works fine. For example, I've had some light falloff when using a 135mm lens for 4x5 with some 4x5 enlargers I've used, but using the same 135mm lens in an 8x10 enlarger when printing 4x5 works just fine, no noticable falloff. I wouldn't want to use a 240mm lens with an 8"x10" coldlight head, but with a 12"x12" head it works just fine.
Bottom line, I would imagine that the 240mmm Componon-S would work just fine for 8x10. It is certanly worth trying. If it proves inadaquate, I could probably be convinced to sell my 300mm Rodagon (I no longer own the 300mm El Nikkor).
Jim, I know that my cared for babies have found their new and rightful home. I have used the Componon-S to enlarge up to 20x24 and have noticed no loss of sharpness at the corners versus the center. Seems pretty even to me. Enjoy!
Michael Mutmansky has indicated that the 240 Componon S would cover 8X10 according to his calculations on the Durst 138S that he converted to 8X10. However, I don't believe that he has used this focal length after the conversion. He did mention the possibility of light fall off with the 240. He uses a 300 mm lens, to the best of my knowledge. I believe that Michael's concern about coverage was when enlargements approach or exceed 20X24 print size.
I have intended to use the 240 Componon S with one of my Durst enlargers if I decide to convert this to an 8X10 Azo enlarger with a UV light source. Thus far that is another project awaiting my time to devote to it.
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As always quick responses with great information.
I don't have an 8x10 enlarger (yet) and was not planning on keeping this lens when I purchased the lot of items from Francesco.
But, this lens is so beautiful I think I'll hang on to it.
Schneider has info on the web about the 240 mm Componon-S at http://www.schneideroptics.com/photo...ng/componon-s/
For what its worth, Schneider recommends the max format for this lens as 180 x 240 mm. For the metrically challenged, this is 7 x 9.5 inches -- almost 8x10. So maybe it will work for 8x10, but it doesn't meet Schneider's quality criteria.
The MTF curves are plotted for a slightly larger format, but they look pretty poor in the outer 10% or so.
Since you already have the lens, it is worth keeping to try out.
Using a 240 for 8x10 is like using a 120 for 4x5, except that you will probably use smaller magnifications (print size / negative size), which will help with coverage.