Unexplicable exposure problem with paper negatives
Over the last few months I've been getting unexplained results for paper negatives [pure white after development] except for very long [2 minutes or greater] exposures
My two Weston V meters checked against Nikon digital camera [100ISO digital camera setting versus 6ISO paper negative]. Gave same ‘reflected’ result after correction for change in ISO rating.
Used four 4x5 paper negatives cut from single 8x10 multigrade paper. Prior paper from same box gave four obviously exposed images
Last tests done with incident readings with sun diagonally behind subject. Camera 3m in front of subject. Same subject and camera-subject distance for all four exposures. All images taken in about 30 minutes.
Four images using 4 different lenses
135mm xenar in copal #0 shutter
4 ¼ inch Wray no shutter, but hat used to control length of exposure
180/315mm Symmar convertible with Ilex shutter – used in both configurations
Both shutters checked for operation and speed accuracy by 'Romanian' tester, and also checked that shutter worked by eye.
Copal as per setting on ‘speed ring’.
Ilex - Actual speeds determined at speed selector dial position.
Way out of speeds on dial, but reasonably consistent
Weston Reading 12 - 12.5 giving exposures of:- 1/8s@f11; 2s@f25; 1/10S@f8 and 1/2s@f22.
The four exposed sheets developed at same time in Jobo 2500 tank with 2504 sheet film holder.
Developed with ‘’Ilford PQ universal” using both old [2 ½ years old} and fresh concentrate [delivered yesterday opened today]
Dark slide removed before exposure.
Camera:- Calumet CC400
Any and all help welcome
regards
Tony
Re: Unexplicable exposure problem with paper negatives
Re: Unexplicable exposure problem with paper negatives
Did you load all the sheets emulsion side out? A sheet loaded backwards will not be exposed. Not to be insulting... we've all done something similar.
Re: Unexplicable exposure problem with paper negatives
Re: Unexplicable exposure problem with paper negatives
Quote:
Originally Posted by
koraks
What kind of light?
“Last tests done with incident readings with sun diagonally behind subject. Camera 3m in front of subject. Same subject and camera-subject distance for all four exposures. All images taken in about 30 minutes.”
Re: Unexplicable exposure problem with paper negatives
Quote:
Originally Posted by
Mark Sampson
Did you load all the sheets emulsion side out? A sheet loaded backwards will not be exposed. Not to be insulting... we've all done something similar.
no insult taken - have done so on occasion but not this time
Quote:
Originally Posted by
Pere Casals
What paper did you use ?
multigrade MGIV RC de luxe Pearl
QUOTE=koraks;1503106]What kind of light?[/QUOTE]
Quote:
Originally Posted by
Bob Salomon
“Last tests done with incident readings with sun diagonally behind subject. Camera 3m in front of subject. Same subject and camera-subject distance for all four exposures. All images taken in about 30 minutes.”
Daylight early afternoon bright for UK
regards
Tony
ps the paper has an unknown history. I'm another unknown history box [5x7] which I might try out to see if I've some 'bad paper' in the midst of the 8x10 box
Re: Unexplicable exposure problem with paper negatives
I'd say exposure is a tad on the short side (at least to my taste) but not to the extent that no image would be visible. I'd advise on doing some further testing with tray development so that you can see what you're doing. That way you can at least check of something comes up if you extend development. But it's a mister for sure! Does the paper print OK under normal (enlarger/contact) conditions?
Re: Unexplicable exposure problem with paper negatives
Dead or contaminated developer?
Re: Unexplicable exposure problem with paper negatives
Quote:
Originally Posted by
koraks
! Does the paper print OK under normal (enlarger/contact) conditions?
Don't know, but paper from the 100 box 'worked' without [processing] problems up until [say] 6 sheets ago.
Quote:
Originally Posted by
Andy Eads
Dead or contaminated developer?
I tested today with an unopened developer concentrate [delivered yesterday from supplier]. All containers washed between times.
regards
Tony
Re: Unexplicable exposure problem with paper negatives
No disrespect intended. As I told my students, and as I was taught, first remove all questionable variables. That means one batch lot of non-expired media (paper in this case), certifiably fresh chemistry, one light meter, one lens in same shutter, same time/temp processing.
Experiment with the above until you find your desired outcome. Record the details (above), and then REPEAT the whole regime exactly and if you do not get acceptable results, something in the chain of requisites wrong. Operator error, whacked shutter speed, aperture is where I would look first.
Best of luck and please stay in touch. I am sure a lot of us are looking forward to your success.