I am not sure if I am getting an accurate A7Rii Milky Way picture

[Phalynx]

Somewhat new to astrophotography. I took this photo of the milky way and all the pictures that I take seem to have far too many stars around the milky way than most others I see. It makes me feel like this isn't real (noise or something). This was processed with LR. Original was ISO 6400, 30" at f/1.4.  Why does mine look like it is over sharpened wildly? I didn't add any sharpening.

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[Justo_McGusto]

What lens are you shooting with? It looks like you may be getting a bit of motion blur on the stars. 30 second exposures can start to create star streaks.. Ive seemed to notice people shooting at 25 seconds to prevent this. Here is the science behind the "Rule of 600".. http://photo.stackexchange.com/questions/30263/what-is-the-rule-of-600-in-astrophotography

Have you tried shooting at a lower ISO?

[studio40]

What lens did you use?

Maybe you're exposure was too long. Google for a chart showing the length of exposure in relation to the focal length for milky way shots.

Also you can use the "long exposure noise reduction" somewhere in the camera menu.

With F1.4 you don't need such high ISO. 2000 should be more than enough.

Hope this helps...

Haim

[ajay]

Typically for a 21mm lens I shoot no longer than 10 seconds or so at ISO 3200 and that's with a Canon 5DM3.With that lens, you can go up to about 13 seconds before streaking starts to occur. I would try something similar. Shoot in raw, post-process it to bring out the contrast and you should be fine.

 

The image you show is overexposed in the center and the exposure is too long which causes a slight streaking of the stars.

[Phalynx]

I used a 20mm Sigma. I understand the trails. I have adjusted the exposures to prevent that. I feel like I have more stars than I should compared to other dark sky photos. I am concerned it is noise.

[Phalynx]

I was using ETTR on this shot to see what difference it makes. I normally shoot at 10 seconds at I so 3200 and end up with similar results.

[oneand0]

First start out by throwing it into Capture 1 and then throw the same shot in LR. You will see a huge difference. Let me know what you think after you do this. I absolutely am used to LR and love to use it. But for  Astro I would never start off with it.

[Phalynx]

I played with it a bit in Capture 1. It ended up similar, although not the same. That being said, it didn't change what I think I am seeing that is wrong. I feel like there are far too many stars in the picture. I know the milky way looks cloud like so that doesn't concern me. It is all the extra dark areas with so many stars. I don't see these on any other milky way shots. Either I am picking up more stars that I think I should or I have noise or something.

[oneand0]

Reading at the above replies. I do think it is just a little too much light and ISO that's getting you what you have. I always stick to around 15, 20, no more that 25 seconds. Around ISO 3200 - 6400 @ f/2.8

Happy that you see the difference between LR and Capture One.

[Phalynx]

Here is another shot. I feel it looks the same. 10 sec, f/1.4 20mm ISO 3200  

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[Berek]

As you have noticed it's a smudgy horrible mess. Looks like a low res jpg. I'd check all the menu settings and see if theres something set that shouldn't be. Only shoot raw and turn OFF any NR. The stars look like they're suffering from bad coma in the corners. Haven't checked the lens reviews so could be wrong (probably not at 10sec). Try f2 next time. Try lots, it's all in the exif so you can see what the best settings are.

[rpx353]

Hahahaa! Astroimaging is not easy, in fact it's a lot more difficult than photos lead you to believe, as most are enhanced in photoshop. It takes a lot of experience from trial/error. Your picture is perfectly normal with the settings you have set. The sensor is sensitive enough in the A7 family to pick up more stars than you normally see. I am an experienced astrophotographer and I love the results I get with my A7Rii because it's able to pull the deep stars out better than any other camera except the A7S. The quickest way to test for excessive noise for an overheating sensor is to put the lens cap on and shoot a dark frame. Look at the image and see if you see hot pixels and purple blotches from compression. Later you can use the same reference shot to subtract the noise from your images by stacking them. Doing this will remove any noise that possibly is generated by the camera, potentially eliminating your problem if it is happening at all. From my experience, the camera is very clean in its images (almost perfect in fact) and not producing the noise you suspect.

 

First thing first though, update your firmware to the latest version, as there were many improvements to the noise reduction, and long exposure noise. I shoot raw+jpg, but your cleanest files will always be your RAW! I use jpgs for sharing on the web. So shoot uncompressed raw for the best results. This gets rid of the purple smudges you see from compression. I shoot with NR on, and you may prefer it off, but it provides me VERY clean images when it's on. Even my JPG images are amazing from this camera though..Your ISO settings seem a bit high to me and you just need to bump it down until you get the result you are satisfied with. Your light is bleeding into each other as if it is exposed too long... Some of the stars look like ping-pong balls instead of sharp pinpoint stars. Also, the glass you use makes a big difference in sharpness and clarity. Cheap glass will get you muddy images. I shoot with my Zeiss 55 f1.8 and get razor sharp images, and also with my 28/2 and 90/2.8. These are the top 3 sharpest pieces of native glass Sony is currently offering and are a lot of fun to shoot with. You also have to watch out for dew accumulation also, as that can blur your images without you ever knowing. Many people stack their low exposed photos to control the brightness you are experiencing, but I personally think it's too much work and like single shot images. Always use a lens hood as it makes a difference in the amount of stray light bleeding in, even at night it happens. Last thing you can try is to use a light pollution filter, "fringe killer" or polarizer that will eliminate any stray light and light bleed you might experience, and help to sharpen your image..

 

Overall though, if you shoot in dark skies, you will get a whole mess of stars so much that you cannot make out any constellations. It's easy to lose your place on a clear night with zillions of stars in perfect view. It's not noise, there are actually that many stars, and your camera is good enough to detect them all. So it can be a tricky balance to get the image you want, and it all comes from a lot of practice and many, many shootings. Keep at it and clear skies to you! Hope this helps!

[Phalynx]

Thank you. That makes me feel better. I do shoot raw and have 2.0 firmware. 3.0 dropped last night. I guess I was not expecting so many stars.

[romicva]

@Phalynx,

just curious to find out if you ever figured out settings that you liked. I will have a very limited opportunity to shoot Milky Way with a7rII. Was curious what settings I should start out with.

 

Thanks,

Roman

[Colin Surprenant]

I don't think anyone mentioned turning off IBIS when using a tripod? if it was on, try setting it off as image stabilization with a tripod can have adverse effects.