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/

[Derek Jecxz]

I can provide your with 3FR raw files using the 28mm lens if you'd like. I can do so this evening. Let me know.

But keep in mind, the max H3D exposure is limited to 32 seconds, this may be a problem for you. Otherwise I think you would be very happy with the system.

Kind regards,
Derek Jecxz
www.jecxz.com

[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.

[Derek Jecxz]

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.

Filippo,

Not a problem, the 3FR images are around 50MB each and I can post them on my FTP tonight, I'll set a reminder. I'm in NYC today.

You'll need Phocus to view them, so install that first.

Alex is correct, no bulb exposure - must use PhaseOne backs for long exposure. He is also correct, Hasselblad has promised long expsoure since Noah built the ark.

Questions: I looked at some of your astro photographs (very nice by the way) - how long of an exposure are you using for them? I'm assuming you're using the guided axis movement on the telescope - so how will you couple the H camera to the telescope?

Kind regards,
Derek

[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

[Derek Jecxz]

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

Shhhhhsh!

David said not to tell anyone!

Kind regards,
Derek

[NickT]

Damn did I say that out loud?
Nick-T

[Derek Jecxz]

Damn did I say that out loud?
Nick-T

No, it was with your inside voice.

Kind regards,
Derek

[alexkent]

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

[Jeff]

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.

[Derek Jecxz]

Filippo, Just got home! Will send you a link to some images off forum. Need to eat dinner first.

To the rest of you, trust me, you'll be very happy with the long exposure quality, but I'm not allowed to say how I know. David will never trust me again and he made me promise, back in March!

Kind regards,
Derek

[Jeff]

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.