Schwarzschild with EFKE / ADOX 50

Gast · 2006-01-03T16:07:04+00:00

Hallo, habe den EFKE (ADOX) 50 als KB und Rollfilm mit einem ND3 Filter (ca. -10 Blenden) benutzt und entsprechende lange Belichtungszeiten zwischen 4 und 3...

Gast

Hello, I used the EFKE (ADOX) 50 as 35mm and roll film with an ND3 filter (approx. -10 stops) and calculated the corresponding long exposure times of between 4 and 30 seconds. Unfortunately, the Schwarzschild factor has kicked in here and there is nothing (absolutely nothing) on the negatives. As there are also perfect negatives on the same roll of film that were taken without a filter, I assume there is no fault in the production chain. Does anyone have a tip for me as a starting point for corrected exposure times for the EFKE 50? Thanks and best regards Marc

Christoph

That’s very strange. As this is a single-layer film, the Schwarzschild effect shouldn’t be so pronounced.

MirkoBoeddecker

http://www.adoxfilm.de/ADOX_Filme/ADOX_CHS...DOX_CHS_50.html

MirkoBoeddecker

I think it’s more likely to do with the filter factor and your light meter. Have you tried doing a control test without the filter? Best regards, Mirko

MirkoBoeddecker

It certainly wasn’t an infrared filter for

piu58

Hello, I used EFKE (ADOX) 50 as 35mm and roll film with an ND3 filter (approx. -10 stops) and calculated the corresponding long exposure times of between 4 and 30 seconds. Unfortunately, the Schwarzschild factor has kicked in here and there is nothing (absolutely nothing) on the negatives. As there are also perfectly fine negatives on the same roll of film that were taken without a filter, I assume there is no fault in the production chain. Does anyone have a tip for me as a starting point for corrected exposure times for the EFKE 50? Thanks and best regards Marc [right][post="5698"]<{POST_SNAPBACK}>[/post][/right]

A standard black-and-white film has an exposure latitude of around 12 stops. If your calculation is correct, there should be a further 6 stops above neutral density. That means if you experience even *slight* overexposure, you should be able to see something. Are you sure it wasn’t an ND5 filter (also very common)?

Renate

Hello, I’m currently using Adox 50 a lot for still lifes that I light using artificial light. At f/22 or f/32, I often end up with exposure times ranging from 4 to 16 seconds, and sometimes even longer. I take a light reading using a Minolta light meter. I use the readings as they are, without making any further adjustments. The speed is set to 50 ASA. In A49, I get negatives that enlarge well. I cannot detect any influence from the Schwarzschild effect in this range. Best regards, Renate

Gast

Thanks for the feedback and the link. I took the reading using a Variosix F2 with light metering, and the filter is definitely an ND3, so it’s either a conversion error or I’ll have to measure the filter factor using the Beli. Best regards, Marc