Archived posting to the Leica Users Group, 2001/07/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Erwin, I read your email regarding the RF and it seems you got a littlie bit of work ahead of you? Is it possible to align the Konica RF? if so? would the results be different? Would u be kind do go the extra mile to close this matter. Also the calibration method(?) or amount would be interesting to know. How do I get a hold of your konica 35/2 test report _____________________________________ Thanks, Mehrdad [-----Original Message----- [From: owner-leica-users@mejac.palo-alto.ca.us [[mailto:owner-leica-users@mejac.palo-alto.ca.us]On Behalf Of Erwin Puts [Sent: Friday, July 20, 2001 10:28 AM [To: leica-users@mejac.palo-alto.ca.us [Subject: [Leica] New Newsletter [ [ [In the past two months, while silent on the Lug (for obvious reasons), I [have produced a newsletter for a small group of people, who have a keen [interest in the optics, mechanics, engineering, secrets and use of [mechanical precision engineered 35mm camera systems. With these [afficionados I discussed topics like: a indepth test of the new Hexanon [2/35 lens, the philosophical and ergonomical differences between the M6 [and the Hexar RF, the essence of the SLR and RF viewing systems, the [engineering arguments behind the Hexar/Leica incompatibility, the [artistic differences between Provia100, Kchrome 64, the issue of film [flatness, the concept of depth of focus, and so on. Find below an [excerpt from the latest newsletter. [If you are interested in receiving the newsletter, send me an email with [your address and topics you may wish to have discussed in the future. It [is free, no $18 fee for this service. [ [ [### [Having established in previous newsletters that there is more to [Konica/Leica lens compatibility than the simple measurement of the [distance from flange to pressure plate, I did some further research, now [testing in real life with 100 ISO slide film all leica lenses from 24 to [135mm on a calibrated M6 and a factory provided Hexar, which had the [distance from pressure plate to flange of 27.95mm, thus identical to [Leica but differing from the Konica specs. [As you recall, the Lug was very quick to some simple checks, which in my [view were done not to find the truth, but to 'prove' that nothing is [wrong. This view has been canonized in Nemeng's FAQ. [My results are different. I used a tripod, a high resolution test chart [and a measured distance of 4 meters. All Leica lenses on Leica body were [focused manually several times and the average setting on the distance [ring calculated. All lenses were within 3% of the factual distance and [the slides showed accurate focus under the microscope at the 40X [enlargement. The Leica lenses on the Konica body showed on average a [misalignent of close to 10% and that consistently over all lenses. [I did a special study of the 75mm lens, but not at the allegedly [critical setting of 1 meter (which is not that critical if you study the [shape of the curve). The 3 meter setting is more critical. I first set [the Leica body and the 75mm on the tripod etc. Made a series of pictures [and then I kept this distance setting carefully when using the lens on [the Hexar. Results (microscope) showed a loss of micro contrast, a drop [in edge sharpness and a loss of the very fine detail, including closely [spaced lines. Then I refocused the 75mm using the Hear RF system. [Results were truly bad: slides were unsharp and only the gross outlines [of the test patterns could be detected. I also used the 75mm/hexar at 1 [meter distance. Results were much more acceptable, but not really good, [but not knowing the other results could mislead you in assuming that [the focus was within range. [ [I did this test three times on several days, using several films and [creating every time a new setting and so tried to eliminate any specific [bias. Of course this test is not conclusive, but it does indicate that [the Lug has been too quick to bury the subject. But as Bob Dylan used to [sing: sleep well, Mr President. [ [The monster test of the BW films is underway. [I had some old rolls of Panatomic-X (20 years old), the film that [introduced high resolution acutance photography to 35mm users. I also [used the Maco UP25, 64 and 100, which are all versions of the classical [Adox high actance series of KB films. And an ortho 25, APX25, APX100 and [previous tests included PanF, TM100 and D100. [To keep it manageable I used one developer (the famous CG512) and tried [to develop to the same CI value. You need to do this as otherwise the [steeper curve of the APX25 may lead you think this film is sharper than [as example a D100, while in fact both are as sharp (seen as recording [the same information from the object) but the 25 has higher contrast so [the pictures have more punch, which could be sen as more sharpness. [All pictures were enlarged 14x. which in my view is the minimum to [differentiate meaningfully between films. [The shots were of a model in an old desolated factory, giving ample fine [details, tonal scale and resolution possibilities. [The Pan-X showed outstanding sharpness and acutance, but its grain [pattern was a bit rough but very tight. It resembled the grain pattern [of the APX100, which is a bit finer, and indeed the two films are close. [Finest details however were suppressed by the grain pattern. The tonal [scale showed quite subtle grey values, again till the threshold of the [granularity noise. The whole atmosphere is an image of very pleasing [tonality, gritty sharpness and details painted with broad strokes. [The UP100 (Adox KB21) has surprisingly fine grain, but on inspection the [grain is clumpier but the edge sharpness is low so the fineness is [bought at the expense of definition. Overall quality is still [commendable and while not up to todays standards, in its day it [certainly was a winner. The Pan-X and KB21 images indicate the [progress realized in 20 years of emulsion technology. In itself of [amazing quality, these films lag in all significant areas when compared [to todays super stars. But the differences are on the other hand more [evolutionary that revolution. [The APX100 gives images that suit the reportage style of location [photography very well. These images have a fine realistic imprint: some [what gritty, but with a smooth tonality and sufficient fine detail to [make the scene interesting. [The APX25 has a higher inherent contrast and so small details are [recorded somewhat more forcefully. Grain is absent, which adds a creamy [tonality to the scene, but on close inspection the recording [capabilities are just a small edge compared to the APX100 or PanX. The [finer grain does record the faintest shades of grey values, which adds [to the 3D impression of the scene. [The UP25 (KB14) is very close to the APX25. Grain is slightly more [pronounced, but much less so than PAnX or APX100. The tonal scale is [identical to the APX25. The intriguing characteristic of this older thin [layered, thick silvered emulsion is the edgy grain clumps, which, being [very fine, also roughen up the image structure. It makes the picture [very lively and especially for model photography and architectural [photography adds an effect that can be described as underscoring the [main story. [Compared to the PanF as example the KB14 is definitely less smooth and [its finer details lack the stark micro contrast of the PanF, but all [said, this film is a worthy emulsion, that deserves a try. On a normal [viewing distance, the main subjects literally jump from the picture. [The Ortho25 is a trouvaille: I had some films and asked myself: why not? [In the same setting, the prints proved excellent. The skin of the model [came out very realistic and I did not notice any strange grey values. f [course there was no red in he scene, so all other gray values are more [or less 'natural". Sharpness is excellent and grain very fine. The film [has a clear base and so looks very contrasty, even if the values are [close to normal. Not a film for every topic, but I am inclined to use it [more often and when using some filters can even add some additional [tonal scale. [Definitely a film to try and use for portraits, glamour etc. Take care [of red of course. But more versatile than mostly thought of. [ [As a preliminary conclusion I have to say that the UP25 and Ortho 25 are [very potent films with a potential for intriguing results that need to [be explored. They are not as good as current top performers, but the [distance from a TP as example is less than often imagined. So it is as [easy to note that there is hardly any progress in BW emulsions in the [last decades or to state that we have advanced a big stride to deliver [superior results. [ [If you habitually use enlargements below 10X, the difference are even [smaller. [ [The lesson: try more film than you use now: it will add to your toolkit [and visual awareness. [ [Next: [the PanF, D100, TM100, D400 (new). [ [ [Erwin [ [ [ [ [