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Orion with Sigma 60mm f/2.8

Discussion in 'Astrophotography' started by georgian82, Feb 10, 2016.

  1. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    I recently purchased a used Sigma 60mm f/2.8 lens for astrophotography and I could not be happier with this purchase. This shot is composed of 44 light frames of 3 minutes at f/2.8 and ISO 800 along with darks and bias frames. I also used an Orion Skyglow light pollution filter and it was guided with an Ioptron Skytracker.

    This lens is pretty amazing...no coma at all wide open. There is just a touch of CA and a bit of vignetting which can be corrected with flat frames although I just cropped it out. For $150 (used), this lens is way worth it. Orion 5.

    Cheers!
     
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  2. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Oregon
    Impressively nice image!

    Yes, its a surprisingly good lens even when used on an APSC camera. From reviews such as those at LensTips, the 60mm is the best of the 3 Sigs.

    BTW, which camera body & stacker did you use? It would be really helpful if you could post a single capture so we could see how much stacking helps.



     
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  3. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    Hi there!

    I used a modified Olympus EPM2 and I used PixInsight for image calibration, stacking and post processing. Attached is a single exposure with no post processing of any kind expect that I stretched the image to show what kind of data it contains. As you can see, there is a lot of noise in that image that got cancelled out with stacking. Not only that, but stacking really helped with bringing out more of the nebulosity detail. Orion single exposure 1.

    Cheers!
     
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  4. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Oregon
    Thanks so much Georgian for the added items. Actually, I'm amazed at how little noise I seen in the single frame. You may have seen the series of tests I've been doing on long exposure noise. For a 3 min. shot, this looks really good.

    May have to give PixInsight a demo. I've tried Nebulosity & Starry Landscape Stacker. Find the latter better than the former. But due to distortion w/ the M.Z12mm, they both run into trouble w/ stacks larger than 5 frames w/ no tracker.

    Is removal of the hot mirror the only mod to your EPM2? My EM5 is out for a full spectrum + "heat reduction system" mod.
     
  5. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    Not a problem! Here is a cropped section of that image to show the noise better. Having said that, you have to remember that stacking is not the only tool we use to remove noise and increase the signal to noise ratio. Doing dark frame and bias frame subtraction is a must in order to get clean images.

    I actually did two modifications to my camera...first, I changed the stock filter with a Baader UV/IR cut filter that lets h-alpha waves through and I also sent it to Spencer's in Utah for their "noise reduction" modification which consisted of opening up the camera and filling all the gaps with a piece of metal that acts as a heat sink.

    I highly recommend PixInsight...It is expensive but way worth it. The quality of my images has increased dramatically ever since I started using it. It is a complex program at the beginning but once you learn it you will no look back. I have found tons of very useful information and step by step tutorials that make it all very simple. I have had PixInsight for about six months now and I am finally at a point where I feel more comfortable with it but I am definitely still learning different techniques for post processing.

    If you do give PixInsight a shot, let me know and I will send you the link I use for image calibration which is amazing. Orion single exposure cropped.

    Cheers!
     
  6. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Oregon
    Thanks, very helpful - especially the cropped frame. Still not bad for a 3-min. shot. Did you find the "noise reduction" mod helped?

    During my testing, long exposures at ISO 3200 on the EM5 have so much noise that single DFS in post is of little help.

    As you know, sensor heating from long exposures produces both consistently stuck hot pixels & increased random noise. From conducting many long exposure tests w/ these cameras, I'm certain that in camera LENR is doing something else besides/ in addition to DFS. So pixel mapping is supposed to find bad/stuck pixels but the exposure used is only a couple seconds. The camera firmware is supposed to use the map of bad pixels & impute a signal for the bad pixels from adjacent good pixels or so I've read. At least in the Olympus cameras I've tested, I'm pretty sure something similar is being done when LENR is turned on. The results are so vastly better than anything I've gotten from doing single frame DFS in post, there is no other explanation. And, I'm sure that when LENR is turned off, the bad pixel map is also unused & no imputing of a value for bad pixels is done. That's because the same hot pixels constantly show up in captures when LENR is off but some of those pixels have to have been mapped already.

     
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  7. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Oregon
    Hey, now that I mention it, would you be willing to do a couple dark captures using my standard test settings & put them in DropBox for me? If so, I'd complete a comparison w/ the EM5 & post it on the thread I started about LEN.

    Settings:
    • Body cap on, camera at room temp in low light location.
    • ISO 3200, LENR Off
    • Exposures: 2 & 4 min.
    • RAW capture
    I'm going to do these again after I get my moded EM5 back.

    BTW, can the EP2 be used w/ the newer VF4? Found the answer, yes. Need the hi-res. EVF4 to accurately focus at night.
     
  8. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    I am not sure the "noise reduction" modification helped or not because I never did tests at a particular setting and temperature before I sent it out for the modification.

    I think the reason you are getting so much noise on your tests is because you are using a very high ISO setting. At that ISO setting, you are probably amplifying the noise instead of getting more signal. Read this very good article and you will understand what I mean:
    What is the best ISO for your DSLR for astrophotography?

    Use Sensorgen.info to figure out what is the best ISO for the EM5 for astrophotography. For example, for the EPM2, ISO 800 is the best setting before it starts amplifying the noise. Basically, I wouldn't gain much from upping the ISO after 800...on the contrary, it would be detrimental.

    Hope this helps!
    Sebastian
     
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  9. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    What is LENR and DSF? I am not familiar with those terms.

    Thanks
     
  10. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Oregon
    Yup, thanks, I do understand how ISO, sensor noise & DR works. My standard test uses 3200 because that will reveal LEN w/ shorter exposures. The high ISO I tested at is the result of subject - night landscapes - where stacking & other techniques are less helpful. Basic exposure for a star light only, clear sky landscape is 3 min. f2, ISO 3200. I frequently do night panos as well. So there becomes a practical limit to exposure duration & ISO given you have to turn on LENR. You saw in my post that i did tests of a full range of ISO, up to ISO 400 @ 30 min. Generally, I'd opt to use ISO 1600, LENR on if I can shot at f2. This will produce good results though ISO 800 would be better still but would mean 12 min (24 min total) exposures. If I have any moon light, ISO 800 or even 400 is my norm. But if I'm using my Kowa 8.5mm f2,8, everything doubles. So ISO 3200 is useful sometimes.

    If you send me the tests we'll be able to compare the modified EP2 to the unmodified EM5.

     
  11. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Oregon
    Oops, sorry. LENR=long exposure noise reduction & DFS = dark frame subtraction.

     
  12. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    Got it..thanks.

    I will send you the dark frames you requested next Monday if I can. Sounds good?
     
  13. 50orsohours

    50orsohours Mu-43 All-Pro

    Oct 13, 2013
    Portland Oregon
    I can not believe my eyes how good your first shot is (with an M4/3 camera), and only 1 person had interest to reply. There is a member on FM who's shots you'd love.

    Please post more or post your work here or on FM (FredMiranda.com) - they will be appreciated.

    Check out "starnut's pictures. Search his username in the landscape forum for more amazing captures.

    Ten-Frame Mosaic of Central Orion Region
     
  14. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Oregon
    Yes, that'd be great. I also just realized, a friend has a stock EP2. So I'll probably be able to compare your moded results w/ the stock EP2 +the EM5 before & after mod.

    BTW just saw an ad for new NR software that looks uniquely complete- DeNoise Projects Pro. Does regular NR & so much more including stacking of all kinds. Even supports Fuji RAW. So far, DXO Prime has been the champ in my tests. But this new software claims it can handle the kind of noise produced by long exposures - hot pixels, salt & pepper, gaps (WOW!), banding. Its on special for $35 & has a demo version.
    Denoise projects professional special offer | PROJECTS SOFTWARE

    As you can see from all this, I'm going down all available paths to find good long exposure noise performance in the m43 ecosystem. It I fail, I'm seriously considering a switch to Fuji.
     
  15. Levster

    Levster Mu-43 Top Veteran

    Where did you pick up a modded EPM2? I'd like to get am astromodded camera but I'm leaning towards something like an EOS600D because of their relatively low price.
     
  16. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    Not a problem.

    By the way, please note that I have an EPM2 and not a EP2...the EP2 is an older generation if I am not mistaking so it probably has a different sensor than the EPM2.

    The DeNoise Projects Pro sounds like a pretty good deal for $35 if it can do all of that!!! I paid a lot more for PixInsights LOL!

    I hope that your quest to find a good long exposure noise performance in the m43 ecosystem goes well...Unfortunately you will never be able to beat a cooled CCD sensor for long exposure astrophotography and if maybe that's something you should consider if you really want to push the camera beyond 3 to 5 minute exposures. But then you would be tied to a laptop and to me it throws the whole simplicity of what I am doing away.

    Cheers
     
  17. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    I actually bought it new from Amazon (body only) and I sent it to this guy who lives in the state of Florida to get it modded. His name is Brent Oliver and his business is HyperCams and Mods. He charges something like $230 USD to perform the modification and I definitely had a very good experience with him.

    You can certainly find used modded dslr cameras for sale for a very good price but to me they are just too bulky. If I were starting my search for a camera dedicated for astrophotography, I would be inclined to get a Sony Nex body. They have excellent sensors and can be found on Amazon for less than $200 these days...but then I would have to pay another $230 for the modification.

    Cheers
     
  18. georgian82

    georgian82 Mu-43 Regular

    118
    Jan 17, 2014
    Hi there! Thank you so much for the kind words!!! I have been working very hard at getting the most out of this camera for astrophotography and I feel is working out very well for me so far. I think it's all about expectations...I do realize that a full frame sensor would perform significantly better for astrophotography but that is not to say that good pictures cannot be achieved with m43 system when properly used (taking lots of light frames, dark frames, bias frames and also using a good processing platform).

    I will definitely check out Fred Miranda's website...I have visited a few times but didn't realized that there are other guys out there using m43 for astrophotography.

    Thanks again!
    Sebastian
     
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  19. Levster

    Levster Mu-43 Top Veteran

    There doesn't seem to be a market for them in the UK unfortunately. I can pick up an Astro modded 600D for around $400, but for what I want to use it for I don't think I'd mind the bulk too much. It's probably a bit of an extravagance for me living in the city, I'm not sure how much of a difference having a modded camera would make to me.
     
  20. 50orsohours

    50orsohours Mu-43 All-Pro

    Oct 13, 2013
    Portland Oregon
    Sorry I didn't mean to imply that "starnut" was using m4/3. Wait till you see his rig. He posted it in one of his threads. But I was very impressed with your shot with m4/3. The ones I have seen in the past were all too noisy.