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Orion's Belt

Discussion in 'Astrophotography' started by tbyork2012, Mar 2, 2014.

  1. tbyork2012

    tbyork2012 Mu-43 Veteran

    213
    Nov 14, 2012
    Oxford, UK
    Hi,
    I used modded E-PL5, Olympus 75/1.8 and Astronomik CLS-CCD filter to take multiple 2 sec exposures to stack. I chose 2 secs as this is the limit at which I can still get round stars with this setup. I chose the 75/1.8 as it gives a reasonable flat field for imaging, is sharp wide open and has a large aperture to grab as much light as possible. I shot mainly at ISO 6400, although there were some subs at lower exposures through lowering the ISO, all shot at max aperture and stacked in Deep Sky Stacker.

    This is not as nice as the images in other threads, but shows what is achievable with Micro 4/3rds and excellent native lens, without any tracking/guiding equipment. Although I imagine the Panasonic 42.5mm f1.2 Nocticron would be fantastic for astrophotography simply because it is sharp wide open and has a very large aperture with greater light-capturing ability.

    12876918675_17cac03f97_b_d.

    Boon
     
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  2. euler_spiz

    euler_spiz Mu-43 Regular

    42
    Feb 8, 2013
    Cantabria, Spain
    LP Hoyos
    Awesome! :bravo-009:
    So Oly 75 is not only for shooting beautiful people but it works perfect with stars too! :thumbup:
     
  3. rpringle

    rpringle Mu-43 Regular

    102
    Jan 9, 2014
    Very nice considering no tracker was used. I have my own attempt at Orion a couple nights ago without tracker but it turned out pretty awful. I need to make longer and more exposures which I might be able to try tonight if seeing is good. Personally I would love to have the Voigtlander 42.5mm f/0.95, in terms of raw numbers the light gathering would be great for night shooting. If I get out tonight I'll post my non tracked attempt as well.
     
  4. tbyork2012

    tbyork2012 Mu-43 Veteran

    213
    Nov 14, 2012
    Oxford, UK
    I'm sure the benefits of being on a dark site, i.e. no need for a light pollution filter, will allow more light to reach the sensor. Stacking will help to give better images. Hopefully I will be borrowing my friend's Astrotrac, which should allow for use of 300mm or longer focal length to image Orion again.
     
  5. rpringle

    rpringle Mu-43 Regular

    102
    Jan 9, 2014
    Here's my attempt from last night of Orion in my back yard, seeing was good and I increased my shutter from 1/3s to 1s and took 500 exposures at ISO 6400. Not too bad for no tracking, the color I thought might be a bit off but I've been getting more greens and blues from my E-P5. My D7000 used to give me alot more reds and purples. I used auto WB so maybe that has something to do with it.

    Orion2-Edit.
     
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  6. wjiang

    wjiang Mu-43 Hall of Famer

    What lens and how did you stack it?
     
  7. tbyork2012

    tbyork2012 Mu-43 Veteran

    213
    Nov 14, 2012
    Oxford, UK
    Was that with the Olympus 75/1.8? If so, why did you not take longer exposures i.e. 2 secs? BTW, I did some more of Orion but this time with 50/1.4 lens. I used exposures up to 6 seconds, which gives slightly ovalish stars but at least grabs more light. Used different exposures to try and increase the dynamic range and recover some of the highlight of the Orion Nebula.

    12923994014_7fe25a7238_b_d.

    BTW, if I push the exposure up a little, then some of the hidden H-alpha detail appears at the top of the image.
    12923719153_9b4550daa8_b_d.

    I am thinking the next time I shoot with the 75/1.8, I will try and use 4 sec subs instead.
    Boon
     
  8. rpringle

    rpringle Mu-43 Regular

    102
    Jan 9, 2014
    I was using my 135mm Minolta Celtic lens as I don't own the 75mm 1.8. Thanks for the tips I was trying to use a shorter shutter speed to avoid blowing out the center and also to keep the stars round as I'm using a 270mm equivalent. I'll experiment more with increasing the shutter speed.

    Sent from my Nexus 7 using Mu-43 mobile app
     
  9. Djarum

    Djarum Super Moderator

    Dec 15, 2009
    Huntsville, AL, USA
    Jason
    That H-alpha is the Bernards Loop. I saw hints of this once in my telescope when the city's lights were out from tornadoes. Its a cool feature of Orion that is really hard to see visually.
     
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  10. DoofClenas

    DoofClenas Who needs a Mirror!

    941
    Nov 9, 2012
    Traverse City, MI
    Clint
    Alright, you've inspired me...the next clear night, I'm going out to shoot it with my new 75mm 1.8 and my 200mm f4...I just checked some of my older wide angle shots of the belt, and it's clear as to where I need to focus in the sky.
     
  11. DoofClenas

    DoofClenas Who needs a Mirror!

    941
    Nov 9, 2012
    Traverse City, MI
    Clint
    Well, here's my attempt.

    Shot first with the 75, then decided that wasn't going to be enough focal length, so I put on my 200 f/4 and stopped it down to f5.6 and cranked the iso to 6400 and took ten 1 second shots and stacked them manually...I still can't get photoshop to auto align to save my life.

    EM141717-Edit-20140304-X2.
     
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  12. DoofClenas

    DoofClenas Who needs a Mirror!

    941
    Nov 9, 2012
    Traverse City, MI
    Clint
    Anyone have some suggestions for stacking programs that work on the mac?
     
  13. rpringle

    rpringle Mu-43 Regular

    102
    Jan 9, 2014
    http://lynkeos.sourceforge.net

    I dug this program up from Google it seems to be popular with Mac users and its free. I've never used it as dont own a Mac. Also check out this site, it explains the so called "500 rule". Basically you divide your focal length by 500 to get the max shutter speed possibly for getting round stars. It seems to be logical as it reflects the general shutter speeds I've been using for my wide angle shots in the past and now my tele shots. Maybe this is a bit obvious for more experienced astrophotographers but I found it interesting.

    http://www.davidkinghamphotography.com/blog/2012/11/how-to-avoid-star-trails

    Btw great first shot of orion I find it more challenging than Andromeda because it seems to be dimmer.

    Sent from my Nexus 7 using Mu-43 mobile app
     
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  14. tbyork2012

    tbyork2012 Mu-43 Veteran

    213
    Nov 14, 2012
    Oxford, UK
    This is a proper attempt at imaging the Orion's Belt with the Orion Nebula using the Olympus 75/1.8. I took over 40 subs at ISO 800, 1600, 3200 and 6400 and stacked them together in Deep Sky Stacker. I used 4 sec exposures, so the stars are slightly elongated.
    12954238033_07619369bd_b_d.

    BTW, at f5.6, there is much less light getting to the sensor (3 1/3 stops less light than the 75/1.8) and 1 sec subs is another 2 stops less light gathering power than the settings I used. Also, the E-PL5 I used has been modded to full-spectrum, which allows more sensitivity to the H-alpha band of light. Hence more red in the images.

    Boon
     
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  15. rpringle

    rpringle Mu-43 Regular

    102
    Jan 9, 2014
    Just out of curiosity are you using any filters such as IR 650nm or are you using the EPL5 in full spectrum mod capturing UV/IR/Visible? Thinking about having one of my secondary cameras converted to Full Spectrum. Thanks - Ray
     
  16. tbyork2012

    tbyork2012 Mu-43 Veteran

    213
    Nov 14, 2012
    Oxford, UK
    I was using the Astronomik CLS-CCD filter to block light pollution from the street lamps. This allows the H-alpha, O-III and I think H-beta to get to the sensor. Otherwise the light pollution will affect the image captured.
     
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  17. aloysius

    aloysius Mu-43 Regular

    57
    Dec 18, 2012
    Nevada City, California
    My real name is unreal
    A UV-IR filter is placed in front of image sensors in most cameras because refractive optics are designed to bring visible wavelengths to the same focus, but sensors also record UV and IR wavelengths, which focus to different distances. The extreme wavelengths must be filtered so the digital images are not blurred.

    The usual UV-IR filter rolls off at the red end too soon to record much hydrogen-alpha, which is the deep red, main wavelength put out by emission nebulae. Camera mods are available with a wider bandpass filter so emission nebs can be imaged, while still filtering out the wavelengths that don't come to the same focus. A full-spectrum modified camera, with no filter at all in front of the sensor, will give blurry images if some kind of filter is not used, somewhere in the optical path.

    Mirror optics focus all wavelengths at the same distance, so unfiltered, full-spectrum images remain sharp.

    I'm having an E-PL5 full-spectrum modded because I will use the camera with an ONAG (on-axis guider) from Innovations Foresight, which reflects visible wavelengths to the camera while transmitting IR wavelengths to a second camera used for autoguiding. The full-spectrum camera also leaves me with the option of using an IR-pass filter that is opaque to visible wavelengths, for pure IR photography. Infrared may focus to a different plane than visible light, but filtering out visible light and focusing the IR only, allows sharp IR images.
     
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  18. rpringle

    rpringle Mu-43 Regular

    102
    Jan 9, 2014
    Thanks aloysius I was thinking of getting my gx1 modded for fullspectrum for normal lens imaging. Wondered if I'd need an ir 650nm or 750nm filter for the front or if imaging just full spectrum would work.

    Sent from my Nexus 7 using Mu-43 mobile app
     
  19. tbyork2012

    tbyork2012 Mu-43 Veteran

    213
    Nov 14, 2012
    Oxford, UK
    If you intend to image full spectrum, then you will require a lens which is corrected through the range you are imaging i.e. the lens should be apochromatic for at least 400 to 1000 nm. Otherwise you will end up with an unsharp image as the visible and infrared may not be focused exactly at the same point on the sensor, due to the focus shift. The only lens which is apochromatic for UV, visible and IR (300-1000nm) that is currently available is the Coastal Optics 60mm f4. But the only way you will know if your lens will work in full-spectrum imaging is to test it. You may uncover a native M43 lens which has minimal focus shift between visible light and IR.

    Unfortunately my Astronomik CLS filter blocks IR, so I won't be able to test full-spectrum astrophotography (even though I have the Coastal Optics) unless I shoot without a filter, which is not a good idea under the light-polluted skies here. But modding will help capture more of the H-alpha light from the nebulae. BTW, I wish Olympus would come up with a similar GPS module as the Pentax astrotracer, which will allow for the IBIS to correct for the earth rotation when shooting astrophotography. That would take the E-M5, E-P5 and E-M1 (and perhaps the E-PL5 and E-PM2) to a whole new level in terms of astrophotography.
     
  20. wjiang

    wjiang Mu-43 Hall of Famer

    Well, you guys inspired me to try this:
    orions_belt.

    It's a bit more than the belt, but the 45mm f/1.8 is the longest fast lens I've got. 12x 1.6s exposures at f/1.8, ISO 1600, stacked in DSS. The improvement in SNR from stacking is amazing!