1. Reminder: Please use our affiliate links for holiday shopping!

Weird artifacts with Sony A7 and long exposure photo

Discussion in 'Image Processing' started by NickCyprus, Nov 1, 2015.

  1. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    A bit disappointed and confused today with some strange artifacts (see the area of the clouds) shown on a long exposure photo I took yesterday evening with my new to me Sony A7 :(

    High ISO NR was set to "low" and Long Exposure NR to off (but I think those apply on to Jpegs only anyway - I shoot Raw+Jpeg).

    I only noticed the issue (maybe color banding?) after I uploaded the photo to Flickr. I was advised it might be an issue with my monitor and let me know if you see the issue with the photo or if its just me. Both camera, monitor and LR are set to sRGB.

    After noticing the issue, I thought it might be the post processing (I added contrast +0,25, highlights -100 k shadows +50, clarity +25, noise reduction +25) so I reset the photo to its original import settings and exported it and still got the issue (to a lesser extend maybe but still visible) so that leads me to believe its not the post processing

    The other weird thing is that the photo looks fine and without those artifacts when viewing in Lightroom...

    The shoot was shoot underexposed on purpose.

    Hope its not an issue with the the A7...

    Any ideas?


    22671541585_b787b6cb0a_b. DSC07832-4 by Nick Corrado, on Flickr


    edit: after uploading the photo here, I see that the issue is more visible on Flickr than here...
     

    Attached Files:

  2. fractal

    fractal TalkEmount All-Pro

    Jun 17, 2014
    Southeastern PA
    Chris
    Nick,

    I see them - like you said, more so in Flickr. I'm not sure what caused it but if you crank up the color noise reduction in LR it might clear it up.
     
    • Appreciate Appreciate x 1
  3. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    Thanks Chris!
    Unfortunately adjusting the color NR in LR does not improve it :(
     
  4. fractal

    fractal TalkEmount All-Pro

    Jun 17, 2014
    Southeastern PA
    Chris
    That is disappointing. There is some serious banding and other issues in that sky. Nice shot by the way! I guess you can always convert to B&W.
     
    • Agree Agree x 1
  5. MAubrey

    MAubrey TalkEmount Top Veteran

    Nick, what were your LR export settings?
     
  6. michelb

    michelb TalkEmount Regular

    196
    Oct 27, 2013
    Greater Montreal area in Quebec, Canada
    Michel Brien
    From the EXIF info: 175 seconds ?

    Which lens and adapter were you using ?
    It seems from lack of EXIF info that you were using an adapted lens but the issue of light leaks with some adapters may have contributed to this.
     
    • Informative Informative x 1
  7. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    Yeah, I changed to 100% quality and 350 pixel and that improved a little :)
     
  8. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    That's correct-175 sec.
    Yes, minolta md 24-35 with a cheap chinese no brand adapter (what i've been using for years). I dont think its a light leak issue here though
     
  9. WestOkid

    WestOkid TalkEmount All-Pro

    Jan 25, 2014
    New Jersey, USA
    Gary
    Nick - If you are saying you don't see the artifacts when viewing in LR then it has nothing to do with the camera or the photo. It must be Flickr or your export settings. I am a little confused on your "350" pixel setting. Where are you seeing that in the Flickr export? Are you re-sizing the photo on export? If so, that may be your problem.
     
    • Informative Informative x 1
  10. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    Yeah, not visible in LR even in 1:1
    Gary, its "Image Sizing", "Resolution" at 350 pixels per inch in the LR export not the Flickr ;)

    From what I've been reading such color banding is more intense on under-exposed long exposure photos as this. I like the under-exposed mood, usually process my LE photos in a similar way and I don't remember having the same issue with the previous Nex-6
    Clarity and contrast must have caused some of the issue here since I've noticed that setting the clarity and contrast to +0,00 makes things a little better...
     
  11. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    After some reading on the color banding issue, I've read that Flickr does a lousy job at that - that's why the issue is more visible if you click the flickr link rather than viewing the photo here.
    I also think I should start applying ETTR method more (and decrease exposure in post) than intentionally taking under-exposed shots...

    I'm still confused what's better: to have LENR on or off?
     
    • Informative Informative x 1
  12. WestOkid

    WestOkid TalkEmount All-Pro

    Jan 25, 2014
    New Jersey, USA
    Gary
    I still don't get how something that is not visible in LR is showing up in exported photos and not related to your export process. Are you using the flickr plugin to export or are you exporting to your HD then importing into flickr.
    I agree you shouldn't be underexposing unless there are some highlights in a night/dark scene you are concerned about. Just expose correctly.
    As for ETTR, The risk reward isn't worth it on long exposures. Your A7 has enough dynamic range and shadow latitude. Why risk blowing out a highlight on what might be your only chance to nail the long exposure?
    Regarding LENR - It is generally a good thing but each photo takes twice as long. 3 minute exposure = 6 minutes before the next shot. That's because the camera needs to take an equally long dark frame shot. I used to use it all the time on my NEX 5t because it produced a lot of LE noise(hot pixels) which cannot be removed easily in post. I don't use it on my A7 as it doesn't produce a lot of LE noise. If I were you, I would go out and take a few long exposures with it on and off and see if you can live with it off.
     
    • Informative Informative x 1
  13. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    Thank you so much Gary! ;)

    After I process the photo in LR, I export it to the hard drive and from there I import (upload) it to Flickr.
     
  14. izTheViz

    izTheViz TalkEmount Top Veteran

    537
    May 10, 2013
    Paris
    Yannis Marigo
    Nick,

    Your issue is a classic I experiment sometimes. This also drives me crazy but as Gary said your A7 is not faulty. No worry. You probably see this banding only in jpeg (try prophoto instead of sRGB maybe) and display (due to compression). True that banding looks worst on Flickr...
    Here the long exposure has flattened out the sky to the point where there’s no tonal variety in some areas, causing this banding. This happens more often in underexposed skies.
    I tried many techniques (adding grain, adding noise...) but what works best when you have clouds already is to stretch out the existing cloud/add even more clouds in PS in those "banded areas" using the clone stamp tool or any other technique. I don't care about cheating a bit.

    FYI I switched off the LENR. It does not make any difference in this case.
     
    • Like Like x 1
    • Informative Informative x 1
  15. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    @izTheViz@izTheViz Thank you Yannis ;)

    I plan to visit the same spot this weekend and take the same shot but without under-exposing this time (cause I understood that's the real reason of the banding issue - so I'm the one to blame) and see the results ;)
     
  16. izTheViz

    izTheViz TalkEmount Top Veteran

    537
    May 10, 2013
    Paris
    Yannis Marigo
    No, you're not to blame. You'll never really know when this is going to actually happen. I don't get that each time on all underexposed skies...so...

    BTW, if you want just send me the raw and I'll try to fix that (not committed) or at least "mask" the banding.
     
    • Appreciate Appreciate x 1
  17. cvt01

    cvt01 TalkEmount Regular

    164
    Jan 3, 2015
    I downloaded the full size (6000x4000) picture of your flickr. The whole file is 588 kb in size. That is a very strong jpg compression. I can see artifacts all over the picture not just in the sky (I uploaded a snip of the bridge).
    Capture.JPG
    The jpg quality should be around 60% in LR to export a 24 Mpx file in this tiny size. Then the artifacts show up.
    I normally keep my JPG Quality setting around 96-97%
    Capture1.JPG
     
    • Informative Informative x 1
  18. fractal

    fractal TalkEmount All-Pro

    Jun 17, 2014
    Southeastern PA
    Chris
    why not 100%? ( sincere question )
     
  19. cvt01

    cvt01 TalkEmount Regular

    164
    Jan 3, 2015
    I read somewhere that there is really no visible difference between 95 and 100 but in old versions of LR there was a significant size difference between 97 and 100. The size increase was not linear but there was a jump at 100%
    I did not check in the last few years if this was still the case... I just stick with 97 for everything but the occasional large prints. If anything I should drop it further.
     
    • Informative Informative x 1
  20. NickCyprus

    NickCyprus Super Moderator

    Oct 11, 2012
    Cyprus
    Nick
    Yeah, in the original first uploaded photo, I exported it with a 60% quality but as I later said I tried it with a 100% quality (and uploaded to flickr) and its a little better :)