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Author Topic: cmos sensors for Digital Medium Format  (Read 10129 times)

BernardLanguillier

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cmos sensors for Digital Medium Format
« Reply #20 on: October 24, 2007, 06:30:26 am »

Quote
With a canon and 24mm L lens I get the best results at f5.6 and f8 @100iso at a maximum shutterspeed of 30 seconds.

Anyone ever do the same or longer exposures with a DB?
[a href=\"index.php?act=findpost&pid=148090\"][{POST_SNAPBACK}][/a]

Phaseone recent backs seem to perform well with long exposures.

Regards,
Bernard

Mike W

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cmos sensors for Digital Medium Format
« Reply #21 on: October 24, 2007, 07:38:54 am »

Indeed, but the +line is made for long exposures. I'm looking to find out how other digital backs without this function are holding up.

I think most DB makers list 30 seconds as the longest possible exposure (without using bulb of course)

Quote
Phaseone recent backs seem to perform well with long exposures.

Regards,
Bernard
[a href=\"index.php?act=findpost&pid=148322\"][{POST_SNAPBACK}][/a]
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Dustbak

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cmos sensors for Digital Medium Format
« Reply #22 on: October 24, 2007, 10:23:40 am »

Huh????

Even with bulb none of my backs got further than around 30 seconds. My Leafs only came to about 25 seconds before I got an error (without image).

The noise was really ugly. The best results were with exposures not longer than about 20 seconds.

I have not yet tested my Hasselblad backs (yet).

Why don't people just use something like a Canon or Nikon for long exposures? Much better equipped to do so.
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Mike W

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cmos sensors for Digital Medium Format
« Reply #23 on: October 25, 2007, 07:25:41 am »

Hmm too bad. I was looking into medium format to be able to make larger prints.

As the saying goes; horses for courses....untill digital back makers get it together, I'll be shooting digital 35mm then.

Or film  
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mtomalty

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cmos sensors for Digital Medium Format
« Reply #24 on: October 25, 2007, 10:38:20 am »

Mike

PhaseOne + backs are the clear leader as far as long exposures go.
I have gone 4 minutes with very acceptable results.

As mentioned above Dalsa chipped backs seem to run into trouble once exposures
pass 15-20 seconds.

Leaf has made very visible improvements with regards to long exposure processing with
the introduction of v11 and previously unuseable 30 second exposures reprocessed in
v11 were significantly improved.

Mamiya seems to hit the wall around 10-15 seconds based on secondhand reporting by
users on this site.

With the release of their new processing software,Phocus,later this year Hasselblad
is saying that exposures will increase to 60 seconds
Currently 30 second exposures using an H3D39 are very clean.

You referenced 30 seconds @ f8 as being a requirement for you.
From what I have seen,firsthand, that need is currently met by at least 3 systems
and I would suspect a fourth,Sinar,would not disappoint.

Mark
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