H3DII 39 - Long Exposures

[emmanuelcoupe]

I was wondering if any owners of the h3d II 39 could help me out.
Does the H3DII 39 have a bulb custom option?

Have you tried long exposures in the range of 4 to 15 minutes?

How noisy are the files and would a black frame subtraction method work well here?

Thx

 

[dougpeterson]

Hopefully someone with Hasselblad experience/expertise can answer your question regarding the H3DII-39 and it's limits. However, it is quite safe to say that 15 minutes is very far past it's capabilities.

The only digital backs spec's to exceed 4 minutes are:
Phase One P45+
Phase One P30+
Phase One P25+
Phase One P21+
Phase One P20+

Of these the P45+ is generally accepted as the king of long exposures and the P30+ a close second. All five backs are rated to go to 60 minutes of exposure at base ISO in average temperatures (less when it's hot out, more when it's cold out). I've not personally done any long exposures with the P20+ or P21+ but I can say from personal experience the quality of exposure of a P45+ or P30+ at 15 minutes is still very very good. All five take automatic black frame subtractions and apply those black frames automatically in Capture One.

With digital backs, exceeding the rated maximum long exposure of any given back (any brand) drops quality very quickly. For instance a P65+ is rated at 60 seconds and is quite good at 45 seconds, usable at 60 seconds, poor at 75 seconds and very bad at 90 seconds.

 

[emmanuelcoupe]

Thank you Doug.

I was told that the Hasselblad H4D-40 cam handle exposures longer than suggested (4 minutes)with good results and without black frame subtraction. I however don't know anything else nor have I seen samples nor have I had the chance to try one myself. The only additional information I found was a custom menu option for bulb mode on the official Hasselblad site for the H4D.
This begs some questions, if indeed the H4D-40 performs well (not excellent but well) between say 4-10 minute exposures, with black frame substation would it be even better? up to par with the P45+?

And then the question would be how does the H3D II- 39 compare to the H4D-40 in that regard?

I'm aware that the P45+ has been crowned king but never even saw attempts to compare it to the h4d or h3d system.

So anyone that could help in this regards would be greatly appreciated.
Thx

 

[Jeffg53]

From memory, the H3D could go to 64 seconds. The H4D 40 goes to 256. No dark frame is required and the images at that exposure are noise free. If you do a search, you should find a few old posts about the H4D and long exposures.

Here's the one I meant: http://forum.getdpi.com/forum/mediu...cks/[email protected]

 

[ondebanks]

All five take automatic black frame subtractions and apply those black frames automatically in Capture One.

Doug, does that mean that the black frame is stored separately to the "light" frame? Does the file format out of the camera actually bundle the frames together as two separate arrays, for Capture One to then subtract from each other?

This would be very interesting, as when you enable dark frame subtraction (long exposure processing) on other cameras, they only output the post-subtraction result, not the two inputs.

Ray

 

[ashdown]

Looking at my H3DII-39 (with the latest firmware) the shutter speeds go up to 64 seconds and there is also a Bulb Mode.

I haven't used it for long exposures but would be interested to see how it performs. It has (I'm pretty sure) the same sensor as the P45+ which is famed for its long exposure quality. The H3DII also has better sensor cooling than the H3D using a heatsink instead of a fan. When I have time I will do some experimenting.