Long Exposure of Starry Night

[bsmithy]

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Also thanks for sharing those beautiful pictures! Very nice.

 

--Brad

[farnz]

Welcome to the forum!

 

From the "just in case you care" department, here's a slightly more detailed but basic explanation: ...

I do and thanks.

 

I wasn't aware of sensors with anti-blooming gates and although they're available as an option in the KAF series I'd be surprised if the M8's Kodak KAF-18500 sensor included them. The effect that I'm (perhaps incorrectly) calling 'blooming' is a radial effect where a red outer ring appears around an unavoidably overexposed specular highlight.

 

The article you linked interestingly advocates dark frames up to 5 times the length of the original exposure; clearly this is for astro-photographical applications but

 

Pete.

[bsmithy]

Welcome to the forum!

 

 

I do and thanks.

 

I wasn't aware of sensors with anti-blooming gates and although they're available as an option in the KAF series I'd be surprised if the M8's Kodak KAF-18500 sensor included them.

 

The effect that I'm (perhaps incorrectly) calling 'blooming' is a radial effect where a red outer ring appears around an unavoidably overexposed specular highlight.

 

The article you linked interestingly advocates dark frames up to 5 times the length of the original exposure; clearly this is for astro-photographical applications but

 

Pete.

 

I enjoy discussing and contributing, but I don't want to come across as a pedantic boor (!)

 

I was surprised to find that the M8 sensor does include anti-blooming. I found this bit on dpreview's page on the M8 sensor: "The sensor also includes anti-blooming protection to prevent against image corruption during high light level conditions."

 

I did a short (read: lazy) bit of looking for details on the M9's 18500 to see whether it includes anti-blooming but didn't find anything right away.

 

Apologies if I missed it in an existing post; I'd be interested in seeing an example of the red ring effect if you've got one handy.

 

5x longer dark frames: That's the first place I've ever seen that recommendation. I have heard of averaging multiple dark frames for dark subtraction, but I've got no idea what a longer dark frame would accomplish.

 

--Brad

[jeff_clegg]

I would like to attach an image, but the system ask for an url; I am lost. So be it! One of my trials I used a 50mm sumicron f2.0 at 32 seconds with black frame exposure on a M8 on a tripod. I see what appears to be more stars that I actually saw. Is this blips from the sensor or is it that the sensor picks up more that the human eye? Comments please. Thanks

Jeff C

[ottocrat]

Upload your image to TinyPic - Free Image Hosting, Photo Sharing & Video Hosting and share it via the resulting URL?

[ho_co]

Jeff--see my response at http://www.l-camera-forum.com/leica-forum/about-leica-forum/6909-rules-leica-forum-post1277218.html#post1277218.

 

You seem to be adding to threads that aren't related to your question.

 

Remember, there's a "Start New Thread" button in each of the forums and subforums, which might be a better choice.

[lanetomlane]

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Brad

 

Thanks so much for the detailed explanation, it's certainly clarified a lot for me.

_____________________

Regards, Tom

 

 

 

 

 

Photography by Tom Lane

[SJP]

I would like to attach an image, but the system ask for an url; I am lost. So be it! One of my trials I used a 50mm sumicron f2.0 at 32 seconds with black frame exposure on a M8 on a tripod. I see what appears to be more stars that I actually saw. Is this blips from the sensor or is it that the sensor picks up more that the human eye? Comments please. Thanks

Jeff C

Executive summary: there are two ways of adding images "insert image" needs a URL of the picture, e.g. from Flickr, "attachments" allows adding local files from you computer harddisk.

 

At 32 seconds I would expect that the camera sees more stars than the naked eye, you could check with a star map (note Google earth has one).

 

Anyway another example here M8 24 s, 28/2, ISO 160, tripod obviously

 

[jeff_clegg]

Executive summary: there are two ways of adding images "insert image" needs a URL of the picture, e.g. from Flickr, "attachments" allows adding local files from you computer harddisk.

 

At 32 seconds I would expect that the camera sees more stars than the naked eye, you could check with a star map (note Google earth has one).

 

Anyway another example here M8 24 s, 28/2, ISO 160, tripod obviously

 

Thanks for the response. It makes sense about picking up more stars with the sensor. When you see photos from Nasa of the heavens, it is well populated with heavenly bodies.

Jeff C.

[jeff_clegg]

This is an example of Black Frame Exposure. It was taken with an M8, 50mm F2.0 Sumicron lens at 32 seconds, at f2.0 on a tripod. I was concern about seeing more stars from the picture than what I actually saw, but as it was explained to me is the sensor will pick up more. Any comments would be appreciated.

Thanks,

Jeff C.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[Ro1and]

This is an example of Black Frame Exposure. It was taken with an M8, 50mm F2.0 Sumicron lens at 32 seconds, at f2.0 on a tripod. I was concern about seeing more stars from the picture than what I actually saw, but as it was explained to me is the sensor will pick up more. Any comments would be appreciated.

Thanks,

Jeff C.

 

Jeff- Longer exposures will pick up more stars. With even longer exposures you can take pictures of the Milky Way. I am not positive but I think the settings are; 1 minute, F1.4 and ISO 800 or any other combination that equals these settings.

Roland

[jeff_clegg]

Jeff- Longer exposures will pick up more stars. With even longer exposures you can take pictures of the Milky Way. I am not positive but I think the settings are; 1 minute, F1.4 and ISO 800 or any other combination that equals these settings.

Roland

 

That interesting. In doing the arithmatic, if I go to a much longer exposure, does the "Black Frame Exposure" have a time limit?

Thanks,

Jeff C.

[k-hawinkler]

Jeff- Longer exposures will pick up more stars. With even longer exposures you can take pictures of the Milky Way. I am not positive but I think the settings are; 1 minute, F1.4 and ISO 800 or any other combination that equals these settings.

Roland

 

Thanks. It depends, see for example here D700: Milky Way over Easter Island: Nikon D3 - D1 / D700 Forum: Digital Photography Review and Image data: Nikon D3 - D1 / D700 Forum: Digital Photography Review. If you use a longer lens then exposure times need to be shorter or you get star trails because of the earth rotation. I believe a good starting point is lens wide open, fairly high ISO, and of order seconds exposure, and then feel your way forward from there.

 

K-H.

[designed]

Hi!

 

Sorry to bring up such an old thread, but something similar came across my shoot yesterday.

 

I did a bunch of long exposure shots, most in A-mode, which usually went up to 32 seconds. Then I accidentally made this shot in B with the resulting exposure of 90 seconds. I posted a 100% crop from the middle of the image, but the whole image area is full of those colored spots. Yes, there are the usual dark spots indicating a dirty sensor, but those colorful specks are new to me. Most are green but some are magenta/cyan.

 

Has anyone else have these happen to them? I found these also in the 32 second exposures, altough they were much smaller and usually black. Are these from the uv filter or are these just smaller bits of dust on the sensor or...?

 

I'm getting a bit tired of the moody electronics of the M8, occasional high iso banding and shutter jams, not the mention emptying its battery all by itself on few occasions.

 

Thanks!

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Simply register for free here – We are always happy to welcome new members!

[ho_co]

des, you don't say what lens or what aperture you used; but these look to me like standard old-fashioned diaphragm diffraction spikes.

[designed]

Ah, good point. The lens in use was a Zeiss ZM 35/2 Biogon T*, I think it was f/8 or f/11.

[ho_co]

I think the 'stars' are effective in their own right. But not if you weren't trying to get them.

 

Good to know you can do that when you want to.

 

I think the general feeling here is that generally on the digital M's, lens and body are at their best around f/4, or f/5.6. Stopping down more reduces sharpness even though it increases depth-of-field.

[designed]

Well yes, the diffraction stars are an effect in their own right, the Zeiss seems to generate them all the way from f/2.8 during the night time. Fortunately the pattern is nice, otherwise it might get a might tedious after a while

 

But that wasn't the issue. What I'm interested are the green and magenta spots in the image, which clearly are a result of some problem during a very long exposure. This is a small 100% crop of the center of the image, but those spots can be found everywhere in the picture, including water (so they are not moiré'd stars either).

[jaapv]

To be quite honest, it looks more like dust than anything else.

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Hallo,

Look here: Leica M

[SJP]

agree with Jaap unless it was a LGM attack