Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: sanvandur on August 27, 2007, 07:38:41 pm
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The primary reason I chose Phase One over other digital backs is because of their unique long exposure capabilities. I mainly shoot at night and my exposures can range anywhere between 15 minutes to an hour. P1's new "Xpose Technology" claims to be able to do this. I bought a P21+ for my H1 and under "normal" circumstances it has performed remarkably. However, long exposures are pretty bad when I go over 30 minutes.
Has anybody done and long exposure tests on the new + backs? P1 claims they can go up to one hour. I've done extensive testing on my P21+. The longest I can do is 30 minutes. Longer than that will produce HORRIBLE files (terrible magenta cast and really bad noise). Longer than 30 minutes will also produce some errors on my H1 LCD display:
-At 54 min black calibration shot is only 19 min (not another 54 minutes)
H1 LCD display shows error "Digital Back problem 61:1"
-At 43 min black calibration shot is only 6min (not another 43 minutes)
H1 LCD display shows error "Digital Back problem 61:1"
I've done these tests indoors at 68 degrees F and outdoors at 53 degrees F. Both temperatures produced the same results.
I've conducted these same tests on other H1 and H2 cameras and a view camera and got the same results.
Currently, my P21+ has been in Denmark for over a month. P1 hasn't given me or my dealer any detailed info about what the problem might be. They're "working on it"...
Has anybody had any similar problems, or any difficulty (or success) with exposures between 30 and 60 minutes?
The silver lining to this whole thing is that the loaner back that P1 sent me is a P45!
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...and I forgot to add.
In the past 2 months, Phase One has sent me three new P21+ backs to try to solve this issue. Every single one of them has malfunctioned in the *exact* same way. This can only mean one thing. It's a production issue from Phase One, and not an isolated case. So since their release, I can only assume that not a sigle P21+ back can do a one hour exposure at 57 degrees F, as advertised.
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We just did a 30 minute exposure using a p45+ on Hasselblad V system, the black substitution file was also 30 minutes (exact time of exposure). No errors to report. We will test with a Hasselblad H system tomorrow. The shot was nothing special, just stuck the camera into a dark drawer and shot an image, but it worked very well.
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30 minutes on the P21+ worked perfectly as well. All goes haywire when it goes 40+ minutes.
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...plus, I did all the same testing on a view camera as well and got all the identical bad results.
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Phase One sent me a new P30+ to test while they fix the bug on the P21+. I've been testing the P30+, and it has the same problems as the P21+.
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I don't want to sidetrack this thread but can the older phase backs do any long exposure shots? Just curious. Thx
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I had good success with 20-30 minute exposures at night with my p-45, but have not tried any long exposures with the plus back I have now. 30 minutes was the max exposure time on the regular backs, despite what someone posted here a while ago from Phase One - the back won't do the 2nd exposure if you make it longer than 30 minutes, and it ruins the file.
Tim Ernst in Arkasnas
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I mainly shoot at night and my exposures can range anywhere between 15 minutes to an hour.
Santiago,
Looked at your portfolio. Beautiful imagery.
I am curious to learn, in which circumstances would you use such long exposures. Could you post (or point to) an example of a picture of yours that required 30 to 60 minute exposure?
Many thanks.
Edward
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Thanks E Eduards!
On my website, there's plenty of really long exposures. The longest ones are the moon/star trail shots. Those range between 2-10 hours.