Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,914   Posts: 1,584,699   Online: 691
      
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 21
  1. #11

    Join Date
    May 2005
    Location
    Daventry, Northamptonshire, England
    Shooter
    35mm
    Posts
    7,156
    Quote Originally Posted by SoulSurround
    I am using the correct (100W, 12V) bulb. I can't check the filters anymore as they will be 'ripped out of the head' soon (see post above this one). Thanks for your contribution though!
    Jeroen
    I too own a Durst M605 and found that for colour printing from negs I was getting very short exposure times. I have a Paterson colour analyser and even at f16 which was the smallest f stop on my 50mm lens I was getting exposure times which were less than the analyser exposure dial was calibrated for. The exposure dial stops at about 4 seconds. So at F11 which is one stop bigger then 2 seconds is completely consistent with my experience.

    My solution was to purchase a 75 watt bulb which increases most exposures to between 5 and 8 seconds at f11 and gives room for dodging and burning if required by moving to f16.

    The alternative which was suggested to me on APUG and which I also know will work because I have tried it, is to dial in cyan and increase yellow and magenta by the same amounts thus giving a neutral density effect to increase exposure. So if the correct balance is 45Y and 50M and dialling in 10 C gives a reasonable exposure then increase Y and M by 10.

    I know Durst specify a 100W bulb which raises the question of why it specified this size and not 75W. I have no answer for this except to say that I have never experienced very short exposures with B&W negs so maybe Durst thought that most of the time a 100W bulb would be OK. It is OK for 6x6 negs and a 80mm lens which anyway goes to f22 and also Ok for B&W negs.

    Hope this helps

    Pentaxuser

  2. #12

    Join Date
    Jan 2005
    Shooter
    Plastic Cameras
    Posts
    888
    Images
    5
    Quote Originally Posted by pentaxuser
    - I have never experienced very short exposures with B&W negs so maybe Durst thought that most of the time a 100W bulb would be OK.
    That is odd, because I get those time with 6x6 B&W negatives! I did also get another very helpful tip: screw a ND filter in the enlarger's lens. I don't really like using very small apertures (16 - 22) by the way as the lens performance drops then... don't you have that experience?

    Thanks pentaxuser!
    Jeroen

  3. #13

    Join Date
    May 2005
    Location
    Daventry, Northamptonshire, England
    Shooter
    35mm
    Posts
    7,156
    Quote Originally Posted by SoulSurround
    That is odd, because I get those time with 6x6 B&W negatives! I did also get another very helpful tip: screw a ND filter in the enlarger's lens. I don't really like using very small apertures (16 - 22) by the way as the lens performance drops then... don't you have that experience?

    Thanks pentaxuser!
    Jeroen
    Interesting points you make about lens performance at small apertures. I too have heard that the middle range is better. The usual procedure in the photographic manuals seems to be focus at the biggest aperture and then expose at two or three stops down. Well on my 50mm lens this would be f5.6 or f8 and I would have ridiculously short exposures at f5.6. Most of my prints are at f11 and some at f16.

    I must try to do a print at f16 then the same print at say f11 then f8 then f5.6 to see what difference I can see. Hopefully provided I dial in enough cyan I should be able to get reasonable exposures. Even 10C made quite a difference.

    I suspect that at my usual print size of 5x8 and 8x10 I probably couldn't see any difference but it's worth a try.

    My feeling is that unless there is a real difference in quality then it's not worth the effort to dial in ND unless I need to increase exposure even at f16.

    I'd be very happy to hear from our members about the scientific truth of enlarger lens performance at small f stops and more importantly its practical effect on print quality. The great thing about APUG is that we have members with more experience than I could now gain even if I am still alive and in the darkroom until I am about 80.

  4. #14

    Join Date
    Jan 2005
    Shooter
    Plastic Cameras
    Posts
    888
    Images
    5

    Boohoo

    Quote Originally Posted by SoulSurround
    However, I found another way to 'solve' the problem. I sent the head to 'Heiland':

    http://www.heilandelectronic.de/html...grade_main.htm

    to have a splitgrade module installed (I already own a controller for another enlarger, hence this step was cost-efficient).
    Mmm, just got back the head from Heiland, and although it works like a charm... my printing times are still way too short.

    Details:
    * 6.7x6.7 inch print
    * 100W 12V lamp (Osram HLX XENOPHOT)
    * Schneider Componon-S 80mm f/4 lens (stopped down to F/8)
    * Kentmere VC Fineprint (Finegrain) paper

    Time is just above 1 (!!!) second and the heiland splitgrade selects grade 3.6 (the contrast it measured was 0.8).

    Just to be clear, we are talking about a black and white 6x6cm negative (Kodak TRI-X 400).

    I am clueless :-(
    Jeroen

  5. #15
    resummerfield's Avatar
    Join Date
    Jan 2005
    Location
    Alaska
    Shooter
    Large Format
    Posts
    1,301
    I’m just guessing here…… Your M605 must have a transformer to set the bulb voltage to 12v. Is it set-up for the correct mains input voltage?
    —Eric

  6. #16

    Join Date
    Jan 2005
    Shooter
    Plastic Cameras
    Posts
    888
    Images
    5
    Quote Originally Posted by resummerfield
    I’m just guessing here…… Your M605 must have a transformer to set the bulb voltage to 12v. Is it set-up for the correct mains input voltage?
    I just measured the voltage over the lamp, it varies between 11.6 and 11.7 Volts which seems reasonable... unfortunately :-(.

  7. #17

    Join Date
    May 2005
    Location
    Daventry, Northamptonshire, England
    Shooter
    35mm
    Posts
    7,156
    Quote Originally Posted by SoulSurround
    I just measured the voltage over the lamp, it varies between 11.6 and 11.7 Volts which seems reasonable... unfortunately :-(.
    There seems to be no obvious reasons for these very short exposures. So now is the time for possibly ridiculous suggestions. Here's one. Most of my shots are outside in good light but I sometimes take shots inside churches where the light is poor. In order to be able to handhold the camera I tend to underexpose which results in thinner negatives. These require me to dial in neutral density with the cyan dial even at f16 and a 75watt lamp. They print OK so if anyone looked at the print it would not be obvious that the negative is thin but when compared to the other negs there is a difference.

    Could it be that your negs are either underexposed or underdeveloped?

    Are you processing your own negs? If not try and compare your short exposure negs with others you know to be fully exposed and developed to see if there is a difference.

    Just a longshot. I hope there are others whose diagnostic skills and knowledge are better than mine and who can get to the bottom of your problem.

    Pentaxuser

    Pentaxuser

  8. #18

    Join Date
    Jan 2005
    Shooter
    Plastic Cameras
    Posts
    888
    Images
    5
    Quote Originally Posted by pentaxuser
    Could it be that your negs are either underexposed or underdeveloped?
    The negative I used was a tad underdeveloped. But I did determine the time I would need to get 'maximum black' in the print and that comes down to about 2.5 seconds at f/8.

    I think I have no other option than to buy a greyfilter that filters out two stops. Now the best way would be to place a filter in the head itself. But then I can only place it directly after the lamp, which gets very hot:

    Are there people that can advise me whether there are greyfilters that can cope with heat? Maybe ones that are used with (non-flash) studio-lighting?

    The other option is to screw a filter on my Componon-S... which will hopefully not degrade the quality visibly.

    Thanks in advance for any suggestions!
    Jeroen

  9. #19

    Join Date
    May 2005
    Location
    Daventry, Northamptonshire, England
    Shooter
    35mm
    Posts
    7,156
    Quote Originally Posted by SoulSurround
    The negative I used was a tad underdeveloped. But I did determine the time I would need to get 'maximum black' in the print and that comes down to about 2.5 seconds at f/8.

    I think I have no other option than to buy a greyfilter that filters out two stops. Now the best way would be to place a filter in the head itself. But then I can only place it directly after the lamp, which gets very hot:

    Are there people that can advise me whether there are greyfilters that can cope with heat? Maybe ones that are used with (non-flash) studio-lighting?

    The other option is to screw a filter on my Componon-S... which will hopefully not degrade the quality visibly.

    Thanks in advance for any suggestions!
    Jeroen
    At the risk of sounding like someone who has recently appeared again on APUG and seems to think there is only one correct way which is his way of doing things, there is an alternative to a filter which requires no additional cost.It is to use the cyan dial as if it were a ND.

    I say this because you may not have seen my earlier reply. If you haven't then please have a look. If you have seen it and decided not to try it but to use a ND filter instead then OK.

    You could close the lens by two stops from f8 to f16. This would increase the exposure from 2.5 seconds to 10 seconds. I cannot say that it wouldn't affect your print quality by using f16 but I think you'd find the quality OK. Occasionally I am able to do prints at f11 and very occasionally at f8 and when I do there seems to be no difference in quality, at least for prints which are 20cms x 25cms.

    Best of luck whichever way you go.

    Pentaxuser

  10. #20

    Join Date
    Sep 2004
    Location
    Netherlands
    Shooter
    Medium Format
    Posts
    1,336
    We have search things out for Jeroen. These kind of things are mostly a combination of factors. The Heiland split grade is OK. This HLX100 Watt bulb seems to be on the ++ side, but can be easily changed for a same type 75 Watt bulb. Further his negative seems to be on the thin side but I will measure it later on our TRD-Z Densitometer (Heiland). The used Kentmere VC paper is very sensitive, easy for larger prints, not so easy now for this smaller prints.
    Times around 20 Seconds you will only reach on aperture 8 in combination of a high quality 0,6 ND filter (e.g. Heliopan) to prevent quality loss of the enlarger lens. Differences between F=8-11 are very small, mostly almost undetectable. Only on full aperture and the other end, 16 or 22 you can see the differences.

    We are working with Dunco II 67 enlargers. Very bright and on smaller format RA-4 prints we also have to use the 0,6 ND filter. M605/M670 and Dunco II 67 can share the same type of Osram bulbs (HLX100 or HLX75) so it must be not a big deal to solve most of Jeroens problems in combination with a ND 0,6 for his small prints.

    Best regards,

    Robert

    (Also from the Netherlands)

Page 2 of 3 FirstFirst 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin