Ilford Multigrade IV RC Deluxe Paper and Durst 605 Color Enlarger
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.
This was my first thread ever in APUG and the only one where I haven't had anyone replying. I am looking for comments and help. If anyone can spare the time to re-look at the thread I'd be very grateful.
Originally Posted by pentaxuser
I have an M605 and print on MG IV using dual filtration, so I should be able to help.
I think you're confusing yourself by using the analyzer. Leave it be. Most printers do without them. I have tried them - they slow me down and confuse me.
Dual filtration using Ilford's recommended filter settings works reasonably well. Do some test strips and you'll see. Using that system, I find I can keep the exposure about the same if I change filtration, but that all depends on which areas of the picture are most important.
I usually expose a test strip, then adjust both contrast and exposure, then make a proof print so I can see the whole image, then make final adjustments and work out burning and dodging for the final print.
I do not use any of those analyzers and stuff so I can't really help with that part of your post but a general tip is that if two different methods give you two different answers, then stop using one of them...
If you are getting significant differences in negative density on a roll then you are not getting your exposures consistent enough or you have very different lighting conditions on the same roll.
One tip courtesy of the late, lamented, Barry Thornton. Make all your contact prints at the paper's minimum time for maximum black. This will tell you within a few rolls if you are getting the exposure correct (shadow detail should be good) and if you need to adjust development time (highlight values should be good).
I would not confuse myself unduly with the analyzer at this time. If you use the analyzer, it will require that you have the same conditions for every subsequent print that you program it for. That really isn't realistic unless you have extremely tight controls on your film developing.
The reason that you notice an appreciable difference with the higher contrast grade filtration is two fold. First the higher grade filtration does have a higher density effect to the passage of light and second you are exposing only one of the two emulsions that VC paper incorporates.
I do not print using the maximum black method...never have and don't believe in it. Most photographers that I have encountered do not use it either.
The way that we print is to use the exposure time to achieve proper highlight values and then adjust contrast to achieve the shadow values that we want.
You can use both filtrations to arrive at a filtration between the extremes of using only one or the other if you want. In lieu of that you can use subsequent exposures through each the low contrast and high contrast filtrations. The later method is called split filter printing and does possess some advantages when burning in certain areas of a print.
Good luck to you.
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Just to clarify, I would not suggest using max-black time for printing. I use split-grade 95% of the time myself. It is useful for contacts however to fine tune EI and dev time in the absence of more technical methods.
Pentaxuser, I don't know if it is of any use for you.
I print, regularly, with a Durst 1200 color enlarger on Ilford MGIV FB paper. I use a dual filtration, starting a test strip setting the enlarger head at 45 yellow and 24 magenta, what is a grade 2 filtering according with the Ilford charts. When I set the overall time to get the values I'm looking for, I print a whole sheet of paper to decide the contrast and if there is need for more or less contrast, I change the filter settings according to the chart I attached here, that I made with the Ilford info included in the paper boxes. Usually there is no need to adjust the exposure time.
Thanks to all replies so far. While my probe readings between about grade 1 and grade 3.5 agree with those replies that say there is not much difference in exposure, there is a difference. It might just be my probe but if there is a difference and clearly this is bound to be the case at grades 4&5 as filtration is all magenta and in fact from grade 4 onwards Ilford says that double exposure is needed, then it begs the question of why bother to use dual filtration.
Originally Posted by Jose A Martinez
I read the Paul Butzi dichroic head calibration for dual filtration article and got the impression that he was saying that exposure could be kept constant. If he is saying this then I haven't grasped the theory behind this. If he is not saying this and there is differences in exposure between grades using dual filtration then we are back to "why use dual filtration?"
I realise this sounds like the prosecution lawyer attempting to discredit the defence's logic but this is not my aim. It may well be that my logic is faulty and there could therefore be a good reason to use dual filtration but if there is then I have so far failed to understand it.
I am still not clear why the analyser probe registers almost the same exposure for grade 4.5 and 5. Does the extra magenta filtration beyond grade 4.5 make very little difference to exposure. To some extent there would appear to be a flattening of the exposure curve in that the Durst hand exposure calculator for the magenta required for grade 5 only gives a slight increase over grade 4.5 but it's more than the probe gives although up to that point the calculator and probe are very close.
I think I may need to just waste a lot more paper than I have been prepared to until now and experiment. As I write this a thought has just struck me. If I have difficulty in finding zone VII highlights each time on the neg( I am sure I tend to stray into zone VIII or use a part of the neg that is closer to zone VIII than zone VII) but zone VI highlights are much easier to distinguish,
should I calibrate the probe for zone VII against a good print but use zone VI areas of the negs which I think I can more accurately find.
I feel the analyser should be a useful tool and as I said, most of the time it is but I need to find a way of increasing consistency.
I'd appreciate any help from anyone out there using a B&W analyser like mine. It's uses a spot probe to determine highlight exposure which is then stored and then a shadow exposure which is then stored. An internal electronic calculation then produces a suggested grade.
I'd suggest that if the analyser is telling you different exposure times when you vary the filtration, then the analyser is probably more sensitive to specific wavelengths of light and is getting itself confused. When I used an Analyser, I would calibrate it using Grade 2 filtration, let it calculate the exposure time, and then adjust the filtration without adjusting the time.
These days I've tossed the analyser and just do a test strip for each print. I end up with much better prints this way, and I believe the whole concept of analysing for shadow detail is flawed.
If you are getting negatives that print consistently well at around grade 2 or 3, it may be worth considering using Ilfospeed paper and keeping a packet of Multigrade as a stop gap.
Originally Posted by pentaxuser