HDR in Astrophotography

Discussion in 'The Gallery' started by avandonk, Mar 18, 2008.

  1. avandonk

    avandonk Member

    Joined:
    Jul 19, 2003
    Messages:
    393
    Location:
    Melbourne the local universe
    Where HDR really comes into its own is rendering the huge dynamic range of potential intensities in astrophotographs. The image below was produced from six sets of exposures. I can also cool my Canon 5DH with a Peltier fridge to 25C below ambient. These images were taken with the 5DH in the fridge at -10C.

    Canon5DH, Canon 300mm F2.8L at F2.8. Six sets of exposure from15s at an ISO of 200 sequentially doubled to 4min at an ISO of 400 ICNR on. Converted from raw to tiff and corrected for flats with ImagesPlus. Stacked and aligned with Registar. EasyHDR used to generate and LDR image from this data.

    The image is an area with a field of view 6.8 x 4.6 degrees. The bright orange star is Antares.

    The dynamic range is potentially 18 bits or 18 stops.

    Large Image 1.6MB
    http://members.optusnet.com.au/~avandonk1/rho.jpg

    Bert

    [​IMG]
    Click to view full-sized image!

    [​IMG]
    Click to view full-sized image!
    Hosted by UGBox Image Store



    Hosted by UGBox Image Store
     
  2. brasher

    brasher Member

    Joined:
    Jul 2, 2006
    Messages:
    849
    Very cool, no pun intended :thumbup:
     
  3. afro

    afro Member

    Joined:
    Jul 23, 2001
    Messages:
    1,099
    Location:
    Adelaide
    wow that is pretty amazing!
     
  4. Irrational

    Irrational Member

    Joined:
    Oct 19, 2004
    Messages:
    721
    Location:
    Adelaide, SA
    Very nice.

    How much did the cooling rig set you back - or was it a DIY?
     
  5. Lukey

    Lukey Member

    Joined:
    Mar 5, 2005
    Messages:
    1,886
    Location:
    Newcastle, NSW
    This is such a seriously sweet setup... Would love to be able to do space shots :D
     
  6. azz

    azz Member

    Joined:
    Nov 23, 2002
    Messages:
    3,863
    Location:
    Heidelberg, Melbourne
    Very nice....

    What is the longest exposure length that you need the extra cooling for?

    Also, do you know someone by the name of Robert Lee?
     
  7. aokman

    aokman Member

    Joined:
    Jul 12, 2001
    Messages:
    13,866
    Location:
    Mexico
    Is that NGC5139 on the right, if it is im missing a whole lot of action in that field as ive only been going up to 30sec exposures with my 200 F2.8 :eek:

    very nice rig! :D
     
    Last edited: Mar 18, 2008
  8. Iscran

    Iscran Member

    Joined:
    Nov 17, 2006
    Messages:
    635
    Location:
    World Traveller
    That's brilliant, I'm very envious of your setup.
     
  9. Zee

    Zee Member

    Joined:
    Oct 27, 2002
    Messages:
    11,535
    Location:
    SYD/MNL/SIN/SFO
    Very nice!
     
  10. s-a-m

    s-a-m Member

    Joined:
    Jan 31, 2007
    Messages:
    20
    Location:
    Brisbane
    Awesome dude! love your work
     
  11. sgtraven

    sgtraven Member

    Joined:
    Sep 10, 2004
    Messages:
    3,043
    Location:
    Vic, Glenroy
    From what i can see

    Timer Remote
    What lens is that 600mm or 400mm?
    are you using a tele converter on it? 1.4 or 2x?
    Cooling for the sensor so that theres no hot spots yea?
    Tracking Tripod (prob attached to normal telescope one.


    we would love to get some details on your setup chief :)!!!!!!!!!!!!!
     
  12. sgtraven

    sgtraven Member

    Joined:
    Sep 10, 2004
    Messages:
    3,043
    Location:
    Vic, Glenroy
    300 then :)
     
  13. peewee82

    peewee82 Member

    Joined:
    Jul 12, 2005
    Messages:
    900
    Location:
    Brisbane
    Pretty colours! You rarely see such a range in astrophotography.

    Cooling the sensor reduces noise over long exposures.
     
  14. OP
    OP
    avandonk

    avandonk Member

    Joined:
    Jul 19, 2003
    Messages:
    393
    Location:
    Melbourne the local universe
    The fridge youcan get from dsmith for $30. I bought two and moved one Peltier assembly onto the other fridge so it now has two. I replaced the Al vanilla heatsinks with CPU heat pipe ones. Better fans with a lot more grunt and speed controlled. I also replaced the Peltiers with higher spec ones (jcar).
    The fridge can pump 80W of heat with two Peltiers running at 6A and 13.8V.
    It can attain 25C below ambient. The sensor noise at -12c is very low so then very faint objects can be captured.

    I can do exposures up to 20 minutes if needed.

    aokman the globular cluster is NGC 6121 or M4 in Scorpio. The region is known as the Rho Ophiucus Complex and is notoriously difficult to capture. The faint coloured nebula are at about noise level at 20C hence the cooling.

    More images

    [​IMG]
    Click to view full-sized image!
    Hosted by UGBox Image Store

    [​IMG]
    Click to view full-sized image!
    Hosted by UGBox Image Store

    [​IMG]
    Click to view full-sized image!
    Hosted by UGBox Image Store
     
  15. OP
    OP
    avandonk

    avandonk Member

    Joined:
    Jul 19, 2003
    Messages:
    393
    Location:
    Melbourne the local universe
    This is a single frame taken with the Canon 5DH in the fridge at -10C degrees and the 300mm F2.8L. The exposure was one minute at an ISO of 1600, ICNR on. I have made the background fully visible by increasing the brightness.

    The frame was corrected for flats and digitally developed in ImagesPlus. Final levels in PS no curves.

    As you can see there is almost no obvious noise. ICNR leaves many small dark 'holes' at 20C.

    Large full image 2.1MB
    http://members.optusnet.com.au/~avandonk1/1600frame.jpg

    Bert

    [​IMG]
    Click to view full-sized image!
    Hosted by UGBox Image Store

    [​IMG]
    Click to view full-sized image!
    Hosted by UGBox Image Store
     
    Last edited: Mar 19, 2008
  16. OP
    OP
    avandonk

    avandonk Member

    Joined:
    Jul 19, 2003
    Messages:
    393
    Location:
    Melbourne the local universe
    Here is what the same system can do with the area around Orion.

    large image 1.4MB
    http://members.optusnet.com.au/~trlee8/ORbs_hdr.jpg

    This with a telescope 670mm FL at f/6.7.
    Large image 1.7MB
    http://members.optusnet.com.au/~trlee8/ngc3293.jpg

    and another same telescope
    Details
    Canon 5DH. 100ED with AP FR/FF f/6.7, Hutech LPR filter.
    250ISO 5x(7s, 15s, 30s), 500 ISO 5x( 30s, 1m, 2m, 4m), 1000ISO 5x(4m, 8m) with fridge at 4C. Converted from RAW to TIFF and corrected for flats with images plus. Aligned with Registar and generated an LDR from this data with EasyHDR. This image has more than 20 bits or 20 stops in dynamic range. Notice how the stars have colour and yet the very faint red nebulae are visible. The fact that the stars have colour means that they are not saturated by the sensor so they end up white.

    Large image 2.0MB. NGC 3532 in Carina
    http://members.optusnet.com.au/~fmlee/NGC3532haf.jpg

    Bert
     
    Last edited: Mar 19, 2008
  17. Lukey

    Lukey Member

    Joined:
    Mar 5, 2005
    Messages:
    1,886
    Location:
    Newcastle, NSW
    Wow they are just amazing. Really brings it back into perspective about our little lives doesn't it? :p
     

Share This Page

Advertisement: