DSLR gurus: some advice please
3I’ve been struggling with various artifacts in my night sky photos. This pic of tonight’s moon is an excellent example of the most annoying issue. There’s a pronounced halo surrounding the immediate edges. Most obvious from about 30* to around 190*. I’ve been all over the map with the settings and can’t find the right combination to knock out that halo. Is this just a fact of life when taking celestial photos with consumer level equipment?
Any suggestions?
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You’re going to have to zoom and crop a section. The image upload compressed the hell out of it and we don’t see any halo.
@mike808
Apparently, you only have to compress the hell out of the image to remove the halo.
It’s probably bleed from the CCD chip itself because the oversaturated contrast/intensity differential at the boundary is so great.
General purpose photography is likely very different than astrophotography, and astronomers probably use specialized CCDs in their cameras, not prosumer DSLRs.
You also might want to explore the high dynamic range options/features/settings. Might help.
Like @mike808 said, it’s probably noise in the sensor itself. Exposure stacking may help, if you don’t have built in hdr functions and don’t mind a bit of post processing work. Though it’s usually used for more distant objects in the sky, it might be worth a try. Here’s a tutorial and a piece of free software: https://astrobackyard.com/deep-sky-stacker-settings/
It doesn’t seem to be a common problem known to Google, though. This tip may also help, especially if you’re getting the problem when processing the photo: https://www.dpreview.com/forums/post/9048578
Wait, more googling with better words led to this:
https://www.dpreview.com/forums/thread/3992895
@djslack @ruouttaurmind
Note to self. DPReview.com is not the site you’re looking for.
@djslack Thank you for the Google-fu. According to the DPReview crew in the thread you linked, this is a very common problem with lunar photos.
The consensus there seems to be it happens in post, so fix it in post. In my case, I didn’t do any post processing on the image so this is more likely caused by the cheap (ish) CCD in my less than top shelf camera or optics I suppose. Apparently I’m destined to clean it up with post anyway.
¯\_(ツ)_/¯
Though some of the folks in the linked thread seem to actually like the effect.
@mike808
Those guys do get deep in the weeds on their digital post processing stuff, don’t they.
@mike808 Not that there’s anything wrong with that… Though I don’t think there’s really a need to review that particular genre.
@ruouttaurmind what @Limewater asked about shooting in RAW would be my next question. Since the best explanation I’ve seen for the effect is that it is consistent with sharpening algorithms and you are not doing any post, is the camera trying to do some post for you?
@djslack @ruouttaurmind I was actually bringing it up to suggest jpeg artifacts as a potential source of the halo. I couldn’t really discern the dimensions of the halo. Even high-quality jpeg has trouble with sharp edges that can cause a halo-like artifact, but it would be limited to fewer than eight pixels from the edge.
And he also clearly jpeg compressed the image to post on the forum.
But yeah, if you’re shooting jpeg then the camera may be attempting to do sharpening for you. I hadn’t even thought about that aspect of it, but it’s definitely valid.
@djslack @Limewater I shoot in RAW, but when bringing the RAW image into Photoshop through Adobe Camera RAW I don’t change the default color space, and don’t import as an Adobe Smart Object. One of the color space geniuses on my staff pointed that out to me this morning. Apparently, in Adobe Camera RAW I should be selecting Adobe RGB as the color space, and bringing into Photoshop as a Smart Object to minimize color loss.
I haven’t had a chance to try this routine on my original image yet to see if it makes any difference. The color girl seems to think it will help optimize the JPG compression yield better results, but also that it will probably not fix the issue. Until I get that RAW file from the SD card in my camera (at home) I won’t be able to see if the original RAW image still displays the artifact.
You guys have been extremely helpful with ideas and tips. Thank you!
I know it’s unlikely, but do you have another lens of similar focal length you could try, to compare?
Are you using teleconverters, telescope?
Can you try your lenses/scope/converter on a buddy’s camera?
@jester747 Nah, no converters, maginifiers, etc. Just a 70-300mm Canon lens.
I’m the rebel with my Canon. Everyone on my staff has Nikon or Sony.
@jester747 @ruouttaurmind /giphy I see what you did there
Also, it’s kind of basic, but you’re shooting RAW, right?
@Limewater @mike808 Wait, now I’m confused which moon we’re talking about exposing.
This is interesting. This artifact showed up on one of my moon photos that I took with an old cellphone and a telescope. It didn’t really show up on the other photo, not that I can tell though… Unfortunately this is not the original photo, but a screenshot of an upload.
@RiotDemon Great pix! Especially considering they were taken with a phone. Nice!
@ruouttaurmind thanks! I just thought it was an interesting thing. I never noticed that halo before! The mosquitos was the worst part about trying to get those photos. I took a ton of photos to get useable stuff because I literally just shoved the phone lens into the eyepiece. I was shocked that it was possible, honestly!
If you have the dslr already, there are special kits so you can attach to a telescope. One day I’ll probably get into it, but for now I just look at
Shooting the full moon can be a tough challenge. Have you tried taking the same photos with a neutral density filter? It’s like sunglasses for your lens.
@shahnm I don’t have any filters at all. Although I’ve had the camera for a couple years, I’ve really just set it to auto and went on my way. But I have frequently been frustrated with the results. I have been planning to learn how to access the various controls and quickly set them on the fly, but this is the first time I’ve gotten serious about it.
I was pretty deep into 35mm SLR photography back when that was still a thing. I still have the Yashica kit I received as a high school graduation gift. But SLR photography was easy-peasy compared to digital. Macro or micro, shutter, aperture, focus, flash intensity, done. Pull the trigger. This Canon must have about a thousand different settings, most of which I don’t even understand what they do. Then there’s the complexity of accessing the settings I do understand. “Press Menu, press Menu again, press left arrow, scroll down, press OK, scroll down…” How am I gonna remember all that crap in the field on the fly?
@ruouttaurmind Actually all of those SLR settings will be the same, and you can control them individually using the manual setting of your DSLR. They work the same way and do the same thing as they did on your SLR. The only thing you have to remember is which wheel or button adjusts what setting, but there are usually only a couple of such controls on most cameras.
DSLRs can make things a lot easier than old fashioned manual control, but still leave you a lot of control of your photos. The Av and Tv settings are probably the most useful, and can usually be accessed by turning the knob that you currently have set to auto. Av allows you to adjust your aperture for when you want control over depth of field, and the camera handles shutter speed to try to achieve a properly exposed photo. Tv allows you to control shutter speed when you want to freeze a moving target (for example), and the camera handles aperture to try to achieve a properly exposed photo. Many cameras also have settings that allow the camera to adjust ISO, though I pretty much always prefer to handle that on my own. I think pretty much every DSLR has a button that you hold down while fiddling with a scroll wheel to adjust ISO.
There are a ton of videos and other references about how to use these settings, but truly the best thing to do is to take your camera and go play around with various settings in various photo scenarios. After all, digital film is cheap!
@shahnm ISO was the first thing I mastered way back in the beginning. The camera is horrible at handling high contrasting lighting conditions. Fortunately there is a dedicated button to access the ISO selection menu. If I were king, pressing the ISO button would advance through the ISO options with each button press so I wouldn’t have to take my eye out of the viewfinder. Unfortunately I still have to reference the rear display to select my ISO of choice. But at least it’s quick and easy on the fly.
I was aware of the AV and TV positions on the dial, but never bothered to figure out which button or dial changes the values without accessing the menu. Unfortunately it doesn’t seem to have a mode which allows me to control both aperture and shutter without accessing the menu in full manual mode. Or maybe there is… as I said, I’m only now, after a couple years, getting motivated to scrape every sliver of satisfaction I can from this camera. It’s been a big disappointment in full auto mode (I could have gotten a point-n-shoot for a fraction of the price and had the same image quality) but that’s all on me because I never learned how to use it. I used my SLR so much every setting adjustment was like a reflex. I could do everything without leaving the viewfinder.
I appreciate the tips! Your advice will serve to keep me on my path to enlightenment.
@ruouttaurmind Just remember to have fun!
@ruouttaurmind Oh - quick thought. There is likely a scroll wheel near where your right thumb or index finger will be when you hold the camera. If you use Av or Tv, that’s the control that will adjust the setting on the fly.
@shahnm As you suspected, there is a dial control and it does control shutter or aperture depending on the feature dial selected.
This will keep me entertained for several days at least. I’ve set up a table and some sandbags so when the moon starts to rise I’ll sandbag the camera and try again. I read last night how the lightweight tripod I’ve been using might introduce some of the artifacts I’ve been trying to quash simply because it’s not all that stable. Sandbagging the camera will provide better stability while also minimizing any vibration.
@ruouttaurmind I’m glad it’s falling into place for you.
It’s amazing how important a stable shooting platform is. For a DSLR, the movement of the shutter is enough to introduce meaningful vibration if the tripod is too light for it. The sandbags are a great solution. Good luck! Please post some of your results.
Oh shit report: DSLR massacre, 09/02/2020.
Yup, I sure screwed the pooch here.
I spent some time reading various DSLR “expert” advice in different forums around the interwebs and changed up some settings in the camera. Most notably, I changed the color profile from sRGB to Adobe RGB, changed the auto-metering default profile, changed the default white balance profile, changed… well, lots of stuff.
I know better. I have many, many years of experience in electronics and tech sectors troubleshooting and hunting down bugs. I know better than to change more than one or two variables at a time. But I figured the “experts” knew of what they wrote, and I am but a padawan. A mere plebe. So caution to the wind, and…
THIS is the RAW image (screen clip of Adobe Camera RAW preview window from a 4K display). Lest you believe something about the screen clip or posting online screwed the pooch, it actually looks worse in person. Conversion to the JPG for posting online actually cleaned up quite a bit. Heh.
@ruouttaurmind It’s a fluffy moon!
Go to the section of your camera’s menu that allows you to reset to factory defaults. Reset. Then try one change at a time from now on…
@shahnm Despite previous claims the moon is made of green cheese, I have photographic evidence it is, in fact, made of sponge cake.
Ya, I did a factory reset last night right after I saw the results of my tinkering.
The camera has the ability to store user definable profiles. At least 3, maybe more. So now I’m going through the process of learning how to use that feature before I get back to the lunar photography deal.
@ruouttaurmind @shahnm
Nah that’s moldy cheese. The moon is like, old.
Hope you sort it out sooner rather than later.
Edit - actually it looks like a fleece blanket before it pills.
@ruouttaurmind If it is in your camera menus, try turning off any sharpening and any smoothing and any compression and any noise reduction. After that, shoot the same image directly in RAW then directly in JPG, or in RAW+JPG simultaneously if you have that choice.
But the image artifact you have seen could be because of the Beyer filter on the sensor.