Some samples for HD3D and 28mm - Landscape Imaging

[filippo]

Hi to all,

I'm quite new to the forum, 80% of my photographic work is dedicated to astroimaging, for which I use specific ccd, the remaining 20% is for Landscape Imaging. For the last activity, my setup is built around Canon bodies and some Canon wide angles. After reading a little bit about the Hasselblad HD3, especially the 31 and the 28mm lenses I was very curious to understand if I can afford the step to add a Medium format camera. I have still some concerns, since I could not find any raw (just 1 that could be downloaded from Hasselblad site) that contains 28mm image taken with the 31 or the 39 Mp. My doubts are about the CA and the real MTF at the borders.
I'm thinking even to make an astroimaging use of the H3D and 28, in this case I should test if the optics are well corrected for inifinity focus.

I would be very grateful if someone could share some raw taken with the 28mm and the H3D or give me some more information about this combo.

Thanks

Filippo Ciferri.

http://www.flickr.com/photos/filippoastro/

[filippo]

Hi Derek,

yes thanks a lot. Just let me know how can we exchange them (network disk or shared directory).

Regarding the exposure, as far as I know, the H3D should have a bulb exposure, is this right ?

Kindly

Filippo.

[alexkent]

Regarding the exposure, as far as I know, the H3D should have a bulb exposure, is this right ?

all the hasselblad digital backs are limited to a maximum 32seconds exposure.
there is no way around this.
if you shoot with a body with a manual shutter, the digital back will stop exposing at the 32sec mark.

hasselblad have been promising us longer exposures for some time, but it's yet to materialise.
PhaseOne digital backs are able to make much longer exposures, but these have their own problems.

[NickT]

all the hasselblad digital backs are limited to a maximum 32seconds exposure.
there is no way around this.

I think you'll find that the 32 second limitation will go away in the near future
Nick-T

[NickT]

Damn did I say that out loud?
Nick-T

[alexkent]

i'm not listening.
not until there is a new firmware download link at the bottom of your message.

[jeff.grant@pobox.com]

Me either, I thought soon was two years ago. Where's the link?

[NickT]

I've heard that the long exposure firmware is in beta now.. I know it's been a long time coming but hey at least it will be free (like the ISO bump), if you were a Phase user you would have had to have paid for a + series..

Nick-T

[filippo]

Hi to all,

nice infos, I hope the 32 sec limit could be removed to open the camera to different uses. Maybe only the ccd temperature noise could be an issue.

Thanks Derek, I'll wait the images.

The astronomical images tipically requires from 10 hours to 30 hours of integration time for good results with an f/8 optic. Only monochrome sensor is used and colors are obtained using different filters. For sampling 30 hours, 7 to 10 different nights are normally required. Sometimes, especially in very dark skies conditions, color sensors could be used (they are less efficient that the monochrome equivalent becauese of the bayer matrix used for obtaining colors).

The Telescope is guided using a mount that precisily counterbalance the earth rotation.

Filippo.

[jeff.grant@pobox.com]

Nick, without wishing to sound like a complaining Aussie, I think that Phase backs have been able to do long exposures for years. If I remember rightly, it was a serious consideration for me when I bought my H3D.

Having said that, I'm eternally happy that I bought the H3D. I can't see Phase or whoever giving me better service than I have received from Hasselblad over the years.

[NickT]

I hear you Jeff. I guess like anything it's a question of priorities as to what gets done and when. IMO the Phase long exposure method is a bit of a pain in that you have to create a black reference at the same exposure setting each time..
Nick-T

[jeff.grant@pobox.com]

Thanks Nick. I'm looking forward to it still, and not needing the dark frame will be a real winner. My Sony does the same thing. It leaves one plenty of time to contemplate the next shot.

[filippo]

Derek,

thanks a lot for the samples.

I have got some problems using phocus, it crashes everytime I try to open an image. I have to study a little bit about it.

Filippo.

http://www.flickr.com/photos/filippoastro/

[alexkent]

Fillippo,

what computer are you running phocus on ? Mac/PC, Which OS and version, ram, graphics card ?
if you give us some details i'm sure we can help you out.

as it happens i've never seen phocus crash when trying to open an image...
if you're on Mac and running OSX 10.4, it will crash when you try to launch the Phocus application (as phocus require 10.5 to function).

regards, alex.

[filippo]

Hi to all,

the computer is a Mac Pro/6GB RAM/2.66 GHz Quad Xeon/Nvidia 120 (512MB)/Mac OS X 10.5.7, Phocus 1.1.3.

Seems that the preview of the Raw is available but as soon as I try some operation inside Phocus, i.e. double click on the image to view it or even export as tiff, Phocus crashes.

Thanks for the help.

Filippo.