As an inexperienced newcomer to darkroom B&W printing I have purchased second hand darkroom equipment including the above and have dipped my toes into printing with varying degrees of success. I have been using single filtration i.e. Y or M according to the Ilford Multigrade instruction sheet to get the grades my analyser(Philips PDT2020) determined to be correct. Obviously the more of either the Y or M dialled-in, the greater the exposure needed. As an exercise I thought I'd try using the dual filtration using a known negative and unfiltered exposure( 5 secs) which had produced an acceptable print. The Ilford sheet says that this needs less adjustment when changing grade which it does.
My above exercise has led to the following results which I'd appreciate comments on.
1. Between grade 1 and grade 3 the increase in exposure using the analyser's probe is very small (about 1.5 secsfrom 6.5 to 8 secs). After this i.e. from grade 3.5 it increases appreciably more.
2.Between grade 1 and 4.5 the above increase as calculated by a Durst Color Calculator disc agrees with the probe to within 0.1 to 0.3 secs.
3. From grade 4.5 onwards the probe gives lower readings than the calculator and indeed shows little difference between grade 4.5 and 5(0.1 secs) although the calculator shows a difference of 1.5 secs
4. The probe exposure readings are consistently but only marginally less with the safelight on than off. ( I use a DUKA 50 safelight designed primarily for color work but seems to work well with B&W). The basic instructions with the analyser says nothing about whether the safelight should be on or off but this seems to demonstrate that it makes little difference. My obvious preference is to leave it on. As you will know a DUKA 50 safelight is a problem if switched on and off due to its warm-up time.
My tentative conclusions/ questions are as follows:
Dual Filtration may or may not avoid the need for any change in exposure between grades 1 and 3 in terms of exposure for print acceptability but this would not be the case if say 1.5 secs( from 6.5 to 8 secs) makes a difference. If so what is the benefit of dual filtration over single?
Why is there no difference in the probe readings for grades 4.5 and 5? Should there be a difference and therefore should I rely on the Durst Calculator instead?
Once I have done an acceptable test print, the probe can then be calibrated to give the same reading on that part of the neg( darkest with recognisable features) and in theory I should then be able produce acceptable prints providing the test neg and the restof the film negs are similar. However therein lies the problem. I find it very difficult to determine what the darkest part with recognisable features is on each neg.
Is there an easy method of doing this as choosing the wrong part of the neg can give quite a large increase or decrease in exposure. I usually end up with several prints out of a 36 roll of film being sufficiently over or under exposed to require re-prints. I know a test print in each case may be an answer but I was hoping to avoid a test print per neg. I like printing but want to be able to keep up a reasonable print throughput.
I then wondered if there was a method of integrating the light from the negative to get an average exposure reading. In that context could I use the diffuser filter which I use for color analysing. I tried this using the same neg I had used in the first exercise. The diffuser withn the spot probe gave consistent but lower readings than the spot probe without the diffuser but once I had re-calibrated it to compensate for the diffuser would this solve the issue of my failing to be able to consistenly recognise the darkest part of the neg with recognisable features.
Printig life is difficult without help but when I discovered this site it became clear to me that there are many users of this site who have experience which in the time left to me as a late beginner I could never hope to accumulate by trial and error. Hopefully some of you can give me the benefits of your experience.
Many thanks
Pentaxuser
My above exercise has led to the following results which I'd appreciate comments on.
1. Between grade 1 and grade 3 the increase in exposure using the analyser's probe is very small (about 1.5 secsfrom 6.5 to 8 secs). After this i.e. from grade 3.5 it increases appreciably more.
2.Between grade 1 and 4.5 the above increase as calculated by a Durst Color Calculator disc agrees with the probe to within 0.1 to 0.3 secs.
3. From grade 4.5 onwards the probe gives lower readings than the calculator and indeed shows little difference between grade 4.5 and 5(0.1 secs) although the calculator shows a difference of 1.5 secs
4. The probe exposure readings are consistently but only marginally less with the safelight on than off. ( I use a DUKA 50 safelight designed primarily for color work but seems to work well with B&W). The basic instructions with the analyser says nothing about whether the safelight should be on or off but this seems to demonstrate that it makes little difference. My obvious preference is to leave it on. As you will know a DUKA 50 safelight is a problem if switched on and off due to its warm-up time.
My tentative conclusions/ questions are as follows:
Dual Filtration may or may not avoid the need for any change in exposure between grades 1 and 3 in terms of exposure for print acceptability but this would not be the case if say 1.5 secs( from 6.5 to 8 secs) makes a difference. If so what is the benefit of dual filtration over single?
Why is there no difference in the probe readings for grades 4.5 and 5? Should there be a difference and therefore should I rely on the Durst Calculator instead?
Once I have done an acceptable test print, the probe can then be calibrated to give the same reading on that part of the neg( darkest with recognisable features) and in theory I should then be able produce acceptable prints providing the test neg and the restof the film negs are similar. However therein lies the problem. I find it very difficult to determine what the darkest part with recognisable features is on each neg.
Is there an easy method of doing this as choosing the wrong part of the neg can give quite a large increase or decrease in exposure. I usually end up with several prints out of a 36 roll of film being sufficiently over or under exposed to require re-prints. I know a test print in each case may be an answer but I was hoping to avoid a test print per neg. I like printing but want to be able to keep up a reasonable print throughput.
I then wondered if there was a method of integrating the light from the negative to get an average exposure reading. In that context could I use the diffuser filter which I use for color analysing. I tried this using the same neg I had used in the first exercise. The diffuser withn the spot probe gave consistent but lower readings than the spot probe without the diffuser but once I had re-calibrated it to compensate for the diffuser would this solve the issue of my failing to be able to consistenly recognise the darkest part of the neg with recognisable features.
Printig life is difficult without help but when I discovered this site it became clear to me that there are many users of this site who have experience which in the time left to me as a late beginner I could never hope to accumulate by trial and error. Hopefully some of you can give me the benefits of your experience.
Many thanks
Pentaxuser