Archived posting to the Leica Users Group, 2002/03/12
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Here is my much delayed write-up of some comparative testing of the above enlarger lenses which I did over a period of several weeks.Please note: I am a hobbyist and not a lens testing guru like Erwin Puts so take this for what it worth. It has been a long time since I attended a University Lab and my testing is of course quite subjective. Hopefully I have included in this process the most necessary/significant scientific controls. Regards, Greg Equipment Used Leica R7, R8 camera. Leica Apo-Macro-Elmarit 100mm f2.8 lens, Leica Apo-Elmarit-R 180mm f2.8 lens, Leica Apo-Telyt 280mm f2.8 lens, Leica Vario-Apo-Elmarit 70-180mm f2.8 lens, Leica Vario-Elmar 80-200 f4 lens, and Leica Vario-Elmar-R 35-70 f4 lens. All of these lenses are the latest version ROM lenses (except for the 280mm lens). Leica M6 (.72) and M6TTL (.85) camera. Latest version Leica APO-Summicron-M Asph 90mm f2 and Leica Summicron-M 50mm f2 lenses. Leica SF-20 flash and Metz 40MZ3 flash on occasion, mostly used in conjunction with the R8 and M6TTL. Leica V35 Enlarger (2), one equipped with the Leica Vario-Contrast Module. The second V35 equipped with Heiland's Splitgrade Controller in place of the Leica Module. Two Leica 40mm f2.8 Focotar lenses. One Schneider 40mm f2.8 APO lens. Peak Critical Grain Focuser. 6X Rodenstock Loupe. Agfa Multicontrast Premium RC Paper No. 312. Kodak Polycontrast II RC Papers (E, F, N). Ilford Multigrade RC - Cooltone, Warmtone. Kodak Dektol Developer, Water Stop Bath, Kodak Fixer. Films used, primarily Fuji Acros 100, Kodak Tmax 100 Ilford Delta 100 and Delta 400. All films were developed in the same small commercial Professional Lab by the same individual using D76. Leica sourced B&W test negatives. After exposure, all papers were subjected to two minutes in the developer (mixed 1 part Developer, 2 parts Water), 30 seconds in the stop bath, Fixed for 1.5 minutes, 10 minutes of rinsing then air-dried. All enlargements were tray developed with liquid temperatures ranging from 73 degrees to 76 degrees F. Testing Conditions All negatives were enlarged at least four times in the middle apertures and twice in other apertures for each lens tested to fit paper sizes from 5X7" to 16X20". Due to size constraints of my easel (maximum setting 11X14"). 16X20 enlargements were mostly limited to print sizes of 8X10 and some 11X14. This was accomplished by setting up the enlarger for 16X20 enlargements and placing one or more smaller papers in the center and/or the corners. Although all f-stops on all three lenses were tested the majority of the testing was done within the range of f 4.0 to f 11. Autofocus Accuracy The first question I wanted answered was regarding the accuracy of autofocus of the V35 with the Schneider lens. This was of course was quite easy: I adjusted the focus at the 8X10 enlargement size using the Peak Critical Grain focuser, printed 8X10, 5X7, 11X14 and 16X20 developed and confirmed with both a visual inspection and a 6X loupe. The result: Autofocus is not held perfectly using the Schneider lens. Very slight focus adjustments are required especially if you are shooting for a fine art print result. However, to qualify this further, I always confirm the focus setting when using a Focotar lens as well. The difference, Focotar 40mm f2.8 lenses used with the V35 required less fine focusing. 5X7 Prints Test results: I could not detect any noticeable qualitative difference at any full stop from f2.8 to f16 between any of the three lenses. Enlargements done at 5X7 are quite quick no matter the f-stop setting. All prints from the same negative appeared exactly alike and could not be differentiated by myself and others (mostly my two sharp eyed girls) without making reference to the indicator markings I placed on the back. One notable performance difference, the Schneider lens is at least one-half to a full f-stop faster than the Focotar's and this was consistently reflected in the exposure times. 8X10 Prints Test results: No detectable difference from f4 to f16 in any of the prints. At f2.8, two of us, on real high contrast prints could see a very slight contrast difference in the very corners of the prints. No visible apparent difference with low contrast negatives. The Schneider lens is superior for this type of print at f2.8 at this enlargement ratio. Both the Focotars and the Schneider lenses performed best at f11 and f8 at this enlargement ratio. 11X14 Prints Test results: No significant detectable difference from f5.6 to f16 in any of the prints. At f2.8 and f4, all three of us, could perceive a very slight contrast difference in the very corners of the prints at f4 and a slight but more notable difference at f2.8. Again, no real apparent visible difference with low contrast negatives. The Schneider lens is superior for these low contrast negatives at the widest apertures at this enlargement ratio. In my opinion, the Focotars produced their best prints at f5.6, the Schneider at f8. 16X20 Prints (and Partial 16X20 Prints) Test results: This is the enlargement ratio where some slight but real differences become more apparent especially again with high contrast negatives such as the Leica Test Negatives. The differences in both contrast and resolution were quite apparent in the corners at the extreme end of the f-stop scale. At f2.8, these differences extent from the corners and along the four outer edges of the prints. At f4, and in some prints at f5.6, the contrast differences are still apparent, resolution less so. These differences diminish at f8 and more so at f11, however, enlargements made with the Schneider lens can be picked out as more contrasty and have better resolution. They appear snappier and not as flat when compared side to side with Focotar prints of this size. Once again, the Focotars produced their best print results at f5.6, the Schneider at f8. The Heiland Splitgrade Controller vs. the Leica Variable-Contrast Module I have been using the Heiland Splitgrade Controller with my V35 since July 2001 and a very significant majority of the prints made during this test process were made using this unit. Why? Primarily for absolute consistency it can't be beat, by using this unit I can very quickly analyze a negative, dial in the paper and not have to manually reset my times when I changed papers. Times recorded here could be used as a starting point for test papers when I switched over to the V35 using the VC module. In my opinion, the V35 is the best enlarger available for printing from 35mm negatives; the addition of the Splitgrade unit simply brings this technology a little more into the 21st century. My Conclusions If you already own, or are planning to purchase a V35, and need or want to buy the best lens for it buy the Schneider. If your enlargements frequently exceed 8X10 and you want the best fine art quality prints buy the Schneider. If you more often print at 8X10 or less, either lens will give you great results. You should purchase whichever lens fits your budget or is available to you (used Focotars do come up at auction from time to time). The Focotar lenses hold the autofocus setting better and this should also be considered when choosing between these two lenses. - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html