Adox CHS 100 roll films corrugated

GilbertMayer · 2010-02-16T19:45:09+00:00

Hallo, Ich bin neu hier und wollte mich zunächst bedanken für den Fotoimpex Katalog und Online-Shop und auch das Forum, dem ich nun beigetreten bin. Ich le...

GilbertMayer

Hello, I’m new here and would first like to say thank you for the FOTOIMPEX catalogue and online shop, as well as the forum, which I’ve now joined. I live in Basel, Switzerland, on the border with Germany and France. I come from a family of photographers and artists. But my path has led me towards film and audiovisual media. It’s only recently, thanks to a bit of a crazy idea (I took my old Contax and Contessa, as well as a Zeiss Ikon Nettar, to Venice to get some rather unusual black-and-white photos in January), that I’ve rediscovered classic photography, and I’ve been obsessed with it ever since (for the past six weeks). That’s why sources for fantastic films, chemicals and papers at reasonable prices are very important to me. And hence my thanks to FOTOIMPEX. Now to my problem with the Nettar. It’s an old folding camera that produces absolutely stunning images when handled with care. I’ve started taking a series of museums as my photographic subject (there are about 30 of them in Basel, and many are housed in interesting buildings, old or new). On a cold winter’s day, I shot a roll film from Adox CHS 100 and developed it as usual in APH 09 according to the formula. The black film edge showed a pronounced waviness, which led to some areas of out-of-focusness; however, this was less dramatic upon enlargement than initially feared. Today I loaded another roll of CHS 100 and made use of the brief spell of sunshine for a second session. This time, however, I always advanced the film to the frame to be exposed just before taking the shot. I noticed that the frame number in the red window had always shifted slightly to the left. But the development then showed that the undulations had largely disappeared. So here’s my tip for folding cameras and Adox CHS 100: always advance the film just before pressing the shutter. This phenomenon has so far only occurred with Adox. Fomapan 400 was absolutely fine. In contrast, the Acros 100 I had with me in Venice hadn’t been wound up tightly at all, resulting in a severe light leak. The camera is fine, though. It winds all films tightly. Perhaps my post can spare other folding camera enthusiasts a disappointment. You should definitely not avoid using the CHS 100, as the problem is really easy to solve. Here is another example of the so-called ‘problem film’. You can clearly see the wavy edge.

Wolfgg

Hello, that looks more like a problem with the pressure plate – either it doesn’t have enough spring tension, it’s jammed, or the spring behind the pressure plate is bent, meaning the pressure plate isn’t pressing the film against the film window at all. Every film has a certain amount of curl; when the camera is carried and subjected to the resulting vibrations, the tension on the film at the film window eases and the curl presses the film ever more firmly against the pressure plate. Regards, Wolfgang

GilbertMayer

Hello, that looks more like a problem with the pressure plate – either it doesn’t have enough spring tension, it’s jammed, or the spring behind the pressure plate is bent, meaning the pressure plate isn’t pressing the film against the film window at all. Every film has a certain amount of curl; when the camera is carried and subjected to the resulting vibrations, the tension on the film at the film window eases and the curl presses the film ever more firmly against the pressure plate. Regards, Wolfgang

Many thanks, Wolfgang Without any knowledge of precision mechanics, the pressure plate seems fine and springs at all four corners. But I don’t know if the force is sufficient. It’s quite possible that the different film stocks and their tension are, in some cases, too much for the old part. With Fuji Acros it was a disaster, but with CHS it can be corrected by taking appropriate measures. HP5, FP4, TriX and Fomapan 400 ran through perfectly. I didn’t test so many types of film out of enthusiasm, but rather bought up everything available in 120 format in the local shops before my trip to Venice. Mostly single rolls. Regards, Gilbert

Wolfgg

Hello Gilbert, The fact that the exposed film is wound too loosely also suggests a lack of spring tension behind the pressure plate, which is supposed to act as a brake during film transport, together with the feed reel. Just for comparison: with a modern camera like the M645, I have to place 320g on the pressure plate for it to start lowering. So if the pressure plate is already touching the back with a significantly lower weight, the springs are worn out; perhaps you could try adding a little foam behind the pressure plate to help out. Regards, Wolfgang

GilbertMayer

Hello Gilbert, The loose winding of the exposed film also suggests a lack of spring tension behind the pressure plate, which is supposed to act as a brake during film transport, together with the feed reel. Just for comparison: with a modern camera like the M645, I have to place 320g on the pressure plate for it to start lowering. So if the pressure plate is already touching the back with a significantly lower weight, the springs are worn out; perhaps you could try adding a bit of foam behind the pressure plate to help. Regards, Wolfgang

Hello Wolfgang Yes, you’re right. I measured the counterpressure of the pressure plate using a letter scale, which was a bit wobbly. At around 180g, it definitely gave way. I’ve now placed small foam pads under all four corners. Unfortunately, the weather is so poor at the moment that I can’t perform any exposure on 100 ASA film with the Nettar, which needs an aperture of f/8–11 anyway to produce a decent image. As soon as I’ve performed an exposure on a roll of film, I’ll get back to you with the results. I’m curious to see how it turns out. Many thanks for now. Regards, Gilbert Right. As promised, here’s the result after I’ve completed the exposure and development of my next roll of film. I took some night shots with Adox CHS 100 roll film in my Nettar, which I had padded with small pieces of foam under the pressure plate, just as Wolfgang had advised. The exposure times were between 20 and 40 seconds and I developed the film at 200 ASA (20 mins in APH09). The problem with the wavy edge has completely disappeared. The edge is sharp and perfectly straight. The image sharpness also seems to have improved at first glance. I’m delighted and would like to thank you very much for the excellent advice. Best regards Gilbert