I'm finally ready to treat myself to a new lens (no more eBay ones for me, thank you!) and was leaning toward the 80mm Super Symmar XL. Then I noticed that for the price of this one lens, I could buy two Digitar series lenses -- the 80mm/f4.5 and 120mm/f5.6 -- instead.

Since I shoot 6x6s almost exclusively these days, I don't need a large image circle but I'm concerned that the 80mm Digitar's 90mm at f/11 is not quite enough, especially as I frequently focus much closer than at infinity.

On the positive side, it's fairly small and light, has a wide aperture for focusing and is presumably optimized for shooting at f/8 and f/11, which will work out well for my shooting style. I'm guessing it might be slightly sharper than the 80mm SSXL, too, given the design tradeoff dictated by its intended usage and presumably, it should provide color and character continuity with the 120mm Digitar as well.

Does anybody have any experience with these two lenses or do I need to be the guinea pig? My primary concern is how conservative (or not, as the case may be) Schneider's published image circle specs are...

Thanks!

-- Jeffrey Goggin (audidudi@mindspring.com), March 10, 2002

Answers

Schneider says in their Digitar brochure that the image circle they state is a function of the given sensor format and thus resolution (since a smaller sensor with the same number of pixels needs higher resolution). The 90mm diameter for the 80mm Digitar is probably quite "conservative" for use with film, since you often need higher resolution for digital sensors - this is also evident by the higher spatial frequencies in the MTF charts of the Digitar series (20, 40, and 60 lp/mm vs. 5, 10, and 20 lp/mm for traditional lenses). A different issue is where they put the field stop, i.e. the cutoff of the field of illumination by the mount. Using a lens at larger magnifications actually _increases_ the image circle for purely geometric reasons: since the lens is farther away from the film than at infinity it projects a larger circle. Arne Croell

-- Arne Croell (arne.croell@inemet.tu-freiberg.de), March 10, 2002.

Jeff, a while back, there was seperate posts on the both the digitar 80 and the SS XL 80. The Digitar got rave revues, awesome resolution, and the SSXL turned out to be the weak link in the SSXL line of lenses. I would go research this in the archives and you will be enlightened. . You wrote.... Digitar's 90mm at f/11 is not quite enough, especially as I frequently focus much closer than at infinity.

Keep in mind these image circles are usually conservative. If you shoot closer than infinity, this will increase the image circle as the lens is further from the film, or maybe I am not sure what you are getting at here? or maybe just a typo?

-- Bill Glickman (bglick@cascadeaccess.com), March 11, 2002.

Yes, I wasn't clear enough. What I meant to say is that I often focus closer than infinity but when I do, I frequently have to stop down further than f/11 in order to get the necessary DOF. Thus my question should read, How large is the image circle at f/16 or f/22? Since 90mm appears to be cutting it close and this gets worse as you stop down further, this is very much a concern for me...

-- Jeffrey Goggin (audidudi@mindspring.com), March 11, 2002.

Jeff: I agree with Bill that the SSXL80 is the weak link in the line. In introducing it, Schneider did not break new technical ground, it only filled a market niche. The Digitar was made for MF and sharp as it is it is not a LF lens because of the narrow IC. No, I do not think that the ICs given by manufacturers are conservative at all, as can be readily seen from their graphs. I have the Super Angulon f/5.6 90mm which I find truly outstanding but it is larger, heavier though better than the 80XL as can be seen from the MTFs. The SA90 was discontinued because of the toxicity of some of the glasses it used, not that this is a concern for users as much as for factory workers. Same with the Biogon for ther Hass. The 75mm SA f/5.6 is still an excellent lens the other choice being the Rodenstock f/4.5 75mm. Yes, at some point you want to go for something exotic but IMO neither the 80XL nor the Digitar deserve are places I would look for that extra umph. There is the 72mmXL but the ergonomics of that lens are worth thinking (or worrying) about before purchasing if you do field work. Some people look at wide angles in the 75mm range as veeeery wide, yet, look at David Muench's work a great deal of which is shot with a 75mm. He uses the Nikkor because of the extra brightness for focusing being an f/4.5 like the Rodenstock.

-- Julio Fernandez (gluemax@sympatico.ca), March 11, 2002.

Julio, that's interesting! I was thinking of trading my 5,6/90 SA for a 80XL sometimes, but after reading your comment I wonder if it's excessive weight is not a small issue in regard of it's excellent quality. I pick this opportunity to let you know that my mails to you have been forwarded back to me for a week. Error message 550 5.1.2 ... Host unknown (Name server: sympatio.ca: host not found). Strange?

Jeffrey I agree with those who think this Digitar has a small image circle for medium format photography. The lens is probably thought for a 4,5 x 4,5 cm chip and would probably allow two cm of rise on 6x6 (5,5 x 5,5), which is little.

-- Paul Schilliger (pschilliger@smile.ch), March 11, 2002.

Julio, I just notice there is a "c" missing in your web address typo. Your delayed mail is on it's way!

-- Paul Schilliger (pschilliger@smile.ch), March 11, 2002.

I appreciate all the input (as well as the lesson in optics, which is something that I don't know much about) but must confess I am tempted to give at least the 80mm Digitar a shot regardless. The price is as low as its resolution appears to be high and because I only intend to shoot 6x6 with it, the small image circle won't be as problematic for me as it would be for others.

BTW, as an aside, the work visible on Paul's site is breathtaking and if you haven't seen it already, do check it out at www.paulschilliger.com

-- Jeffrey Goggin (audidudi@mindspring.com), March 11, 2002.