Haze in lens

[Paul Schilliger]

Wow, isen't this Forum a fantastic knoledgebase? Reading all your contributions helped me to determine that what I saw into the lens whas "bloom". It is not visible when looking thro ugh the lens, but it appears as tiny spots or dust (crystals?) when lookink to a dark surface with a bright s ource of incident light (bulb) nearby. Should I not worry about it? Anyway, I took it for a serie of sho ts, outside, and the chromes are contrasty and very sharp. Thank you! By the way, the G-Claron I ha ve is coated, but are the current G-Claron multicoated?

[M.]

Don' woory n bee hapi.

[TAN K H]

Paul

If you're happy with the results, leave it alone?

To the best of my knowledge, the G Clarons have only been single coated, even those you find new in shutters today.

I haven't exactly been the most careful with blocking stray light with a hood, but the results from my lens (1969-70 vintage 240mm version) have been excellent to date. Good contrast, supersharp corner to corner results at f22 @ infinity. Color balance is fairly neutral and matches my later Schneiders very well.

I have managed to locate two in barrel mounts (a 150mm and a 210mm) recently and when I get them, I will screw them into the shutters which my late Fujinons of the same focal lengths are occupying. I have been looking forward to owning a 150mm G Claron for 1:1 still life work for the longest time.

There are sometimes excellent deals on the barrel mounted versions of these lenses and they are worth picking up since all the G Clarons to date (bar the Wide Angle version) can be used in standard size 0 (150mm),1 (210mm - 305mm) or 3 (355mm) shutters with no expensive modifications. Just use a vernier caliper to ascertain that the length of the lens is about the same in barrel and in shutter, and transfer all shims that came with them.

These are really excellent lightweight lenses to carry round.

BTW Paul, there is a lot of discussion about the G Claron lenses at Ron Wisners Q&A Archives - http://www.wisner.com/archive.htm He seems to recommend these lenses highly even though they fall into the budget Schneider line (after the excellent Xenars). Mr Wisner suggests that Schneider specs are a little too conservative and that the lenses do cover a LOT more than is officially stated (e.g., the 210mm and the 240mm cover 8x10 at f45). He also considers them the modern version of the Dagor.

[Paul Schilliger]

Thanks! I thought you would be interested by some tests I have made recently. So me Times ago, I switched from my flatbed Technika to a VX 125 Monorail. Subsequently, I started to notice soft images resulting from the use of my Fujinon C 300. When an inexpensive barrel Claron pr esented, I thought this was the opportunity to have a close-up lens to fit my Fujinon shutter, and in th e same time, to have a comparison lens for the Fujinon performances. So I made comparison shots, using the more stable Tech, with four of my lenses, shooting a lens testing chart on 6x9 rollfilm, with a di stance of 3 to 5m to keep the same image size, all takings at 1sec. f16. This was a "real situation" test , not a "scientific" lens test. It took into account the camera stability as well as the lens qualities at an average lens stop. The Xenar 210 probably made the sharpest shot (with some color warming up though) fo llowed with almost unnoticeable sharpness difference by the Fujinon C300 (both lenses are from the last decade). Then comes a forty years old Apo-Ronar 360 on Compur 3, still very sharp, and last, w ith noticeable difference, the 25 years old G-Claron. This test reassured me on the Fujinon qu ality, and showed again the importance of camera stability with long lenses. The Fujinon is better than the G-Claron? I'm not sure. Maybe at working apertures of f22-32, things could have changed and showed the Claron more favorably. Also, a different shutter speed could have modified the scores: the G -Claron weighs much more than the Fujinon and therefore can perhaps induce a sway. And my test took into account the center performances only: What about the corners of an 8x10" image? Working dist ance is another factor: I secondly shoot a piece of canvas at 1:5 and the G-Claron image is tack sharp. An objective testing would have supposed several shots at different openings, lens mounted on a very stable optic bench. The purpose of this one was to reassure me on the quality of the recently acquired Fujinon and this was attained! I will now have to work on camera stability to ensure consist ent sharpness in the field! The Toyo VX125 is at it's weakest point with a 300 mm and the slightest breeze w ill ruin the picture sharpness. The Technika in this, is superior and shows much more stability in th e field. ...Perfection still isn't from this world!

[Paul Schilliger]

Well, after reviewing on the comparisons tests, I had an other look at the slide s and, to both my good surprise and greatest embarrassment, I discovered a very sharp corner on the tes t slide made with the G-Claron! So, unless there is a misalignment of the elements in this lens, there has been a film flatness problem in this test. Since there is no trash possibility for my previous post, I apologize and correct this in here.

[Sal Santamaura]

Paul, use of a roll film holder was the most likely source of problems with your test. Such holders all put a reverse curl on the film, which manifests itself as a bulge towards the lens after it's advanced to the image area. Frame 1 is capable of great sharpness, but subsequent exposures can suffer from film plane mispositioning of up to 0.03" over a significant region. My solution when performing critical work like your comparison is to use only the odd frames on a roll. I expose #1, then advance quickly past #2 and stop at #3, etc. That way segments of film which took a set on the reverse curl roller are never within an image.

[Paul Schilliger]

Thanks Sal, good tip on rollfilm use! I would normally use 220 type film and ha ve good results with it, but I made the test with a 120, and I had noticed previously that it sometimes pop's u p, perhaps due to the paper pressure. I will test it anew.

[Sal Santamaura]

Paul, there should be no difference between 120 and 220 regarding the reverse curl/bulge problem. They both suffer from it; paper pressure doesn't seem to make matters any worse compared to the longer paperless variety. Unless, of course, your 220 back is a vacuum type!