In astrophotography, where LE noise reduction is usually off for efficiency reasons, the standard procedure is: It could also be that in aerial mode, a "standard" dark is still subtracted, but it is not good enough ? Or it is noise from the on-chip dark current suppression. If you can do only a few (because it takes a while.) it should still improve the situation. You need many darks to reduce photon noise on the darks. IF temperature has changed, you probably need new darks. IF temperature is about the same, that should solve the problem. Average those, and subtract from your image. If the effect happens only with LE noise reduction OFF (but not with noise reduction ON), you could record 10-20 (!) dark frames (images with lens cap on, same length as your image). If it's confirmed that this red shadow is a problem without LENR, and that Phase One isn't going to fix it, then it would become extremely difficult for me to justify this upgrade. Maybe currently you are the best person to test this, if you still have a technical camera to use Aerial Mode to disable LENR? I can certainly ask my friend to disable Aerial Mode to enable LENR and try again but I have no idea when I can get the feedback. I don't use Lightroom either.Ĭurrently I have no access to the IQ3 100MP so I am unable to do further tests regarding LENR. My Photoshop is still CS6 with ACR 9.1.1 so I am unable to try these problematic raw files. RawDigger reported very low numbers for standard deviation (on the contrary to the histograms I didn't pay attention to) which gave me very high expectation of the digital back. Hopefully this issue can be fixed in the next version of Capture One.Ĭlick to expand.Hi Paul, when I tested the IQ3 100MP I did not specifically test exposures longer than 5 minutes and the only test I made longer than 5 minutes was that 20-minute darkframe alone without LENR. To me it looks like a bug in Capture One. It appears that there is no red color cast of shadow in RawDigger, and there are no higher values of the red channel reported. Then I looked into the darkframe files with RawDigger: There is no red color cast in the shadow at all. Here is a real world picture I made with the IQ250: Note that this is not a lens color cast issue, because LCC has been applied and the 2 minute exposure does not suffer from this red shadow problem.Īfter I looked into these examples, I recalled that when I first tested the IQ3 100MP about 6 months ago I did notice that the darkframe of the 20 minute long exposure looked red.įor comparison, the IQ250 does not have this issue at all. IQ3 100MP + Rodenstock 23mm HR-S, 2 minutes vs 7 minutes: Adjusting white balance does not fix the red color cast in shadow. Note that it's not a white balance problem. IQ3 100MP + Rodenstock 50mm HR-W, 32 minutes: If darkframe noise reduction is disabled with "Aerial Mode", the IQ3 100MP gradually fills up shadow with red color cast if the exposure time is over 2 minutes. I haven't received my IQ3 100MP yet due to the earthquake, but a friend of mine found a problem with it:
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