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Thread: Astronomical photography with H2 & P20 - help needed.

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    Member Analog6's Avatar
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    Astronomical photography with H2 & P20 - help needed.

    I have been out most mornings photographing the planetary conjunctions. As the H2 is not very wonderful at higher ISOs, I have restricted my shooting to ISO 100 & 200.

    So I really have 2 questions:
    1. Is there any way to process higher ISO shots (400-800) so they are not noisy? I have Capture One5 and CS4 and use an iMac.
    2. Does anyone have tips for processing the shots I have already taken to improve them?

    Shots are here (the first 8 are the ones in question)
    Odille

    H2 | P20 | HC 50-110 | HC 150 f3.2 | HC 210 f4 ~ My Website

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    Member Analog6's Avatar
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    Re: Astronomical photography with H2 & P20 - help needed.

    Darn, I had high hopes of you lot, 60 odd views and no suggestions!
    Odille

    H2 | P20 | HC 50-110 | HC 150 f3.2 | HC 210 f4 ~ My Website

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    Re: Astronomical photography with H2 & P20 - help needed.

    Hi Odille.

    My experience with phase one backs is that you will not have much luck with astro photography. I'm sure there are some out there who could help minimize the noise to an extent though.

    The best way I know of is to reduce the resolution, similar idea to pixel binning. The problem is, you run out of usable resolution quick.

    Good luck, I hope you find a happy place with it.


    Mason.

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    Googaliser
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    Re: Astronomical photography with H2 & P20 - help needed.

    Hi - I would recommend shorter exposures at the lowest ISO possible and stacking them in order to reduce the noise, plus dark frames. CCDStack is very good for this - although I have never used my MFD (as much as I would like to) and use a dedicated set-up. Short, stacked exposures also help deal with star drift and thus allowing higher focal length exposures assuming you are not piggy-backing on a German Equatorial Mount.
    Putting the Camera back in the fridge before use may also help - although you need to be careful not to reach dew-point and get condensation issues - not recommended, and harcs back to the old days of astrophotographers using dry ice to keep film cold and reduce reciprocity failure.

    M

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    Re: Astronomical photography with H2 & P20 - help needed.

    Quote Originally Posted by Googaliser View Post
    Hi - I would recommend shorter exposures at the lowest ISO possible and stacking them in order to reduce the noise, plus dark frames. CCDStack is very good for this - although I have never used my MFD (as much as I would like to) and use a dedicated set-up. Short, stacked exposures also help deal with star drift and thus allowing higher focal length exposures assuming you are not piggy-backing on a German Equatorial Mount.
    Putting the Camera back in the fridge before use may also help - although you need to be careful not to reach dew-point and get condensation issues - not recommended, and harcs back to the old days of astrophotographers using dry ice to keep film cold and reduce reciprocity failure.

    M
    +1
    To cool the DB, drape a waterproof canvas bag around the DB, and fill it with dry ice. If you can get an intervalometer, use it to trigger multiple shots automatically. Ideal if you should use an equatorial mount to compensate for the star drift.

    For stacking photos look up the net, there are a lot of articles.
    http://webpages.charter.net/darksky2.../stacking.html
    http://www.fvastro.org/articles/digital/

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    Member Analog6's Avatar
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    Re: Astronomical photography with H2 & P20 - help needed.

    Thanks Googaliser and ajoyroy for taking the time to advise.

    Don't have the dry ice facilities and don't want to risk condensation in the freezer so will it help if I just leave the camera on the cold verandah for the night? bear in mind we are subtropical here so 'sold' is 14-15 Celsius. (Yes, it's hardly what you'd really call cold!)

    I don't have an equatorial mount - so should I do 1/2 to 1 sec shots and stack them? Do they have to align perfectly - or will a stacking program let me do that manually?

    I can set the H2 to just lock up the mirror and keep on shooting, so I could set it to do 10 or 20 half sec shots but they would not line up exactly.

    And I can go down to 50 ISO - so I will try all this tomorrow. It's a small window of time between when they are all visible and sun up but I will report back.

    Off to look at those articles.
    Odille

    H2 | P20 | HC 50-110 | HC 150 f3.2 | HC 210 f4 ~ My Website

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    Senior Member Graham Mitchell's Avatar
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    Re: Astronomical photography with H2 & P20 - help needed.

    Quote Originally Posted by Googaliser View Post
    Hi - I would recommend shorter exposures at the lowest ISO possible and stacking them in order to reduce the noise, plus dark frames. CCDStack is very good for this - although I have never used my MFD (as much as I would like to) and use a dedicated set-up. Short, stacked exposures also help deal with star drift and thus allowing higher focal length exposures assuming you are not piggy-backing on a German Equatorial Mount.

    M
    I might try this next time I have a spare evening. Sounds interesting! I was playing with a friend's 11" Celestron last night but he didn't know how to use it at all and it needs collimation so I might try using my 180mm lens just to see what I can do with it.

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    Re: Astronomical photography with H2 & P20 - help needed.

    I would get a tracking mount for longer exposures, that will allow you to get fainter objects. And stacking longer exposures is really good. I would go to a forum like Cloudy Nights and speak to a community of astrophotographers, although you will be in a rare group, if an individual can be a group, that uses MFD. This image was taken on an Astrotrac which is a tracking mount that can be mounted on a tripod--single exposure, Pentax 645D, ISO 1600

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    Member Analog6's Avatar
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    Re: Astronomical photography with H2 & P20 - help needed.

    Yes, I'd love a tracking mount, not in the budgetary considerations at the moment, though. But definitely on the 5 yr wishlist!

    Lovely astro images
    Odille

    H2 | P20 | HC 50-110 | HC 150 f3.2 | HC 210 f4 ~ My Website

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