Highest ISO during Star Photography?

[Josh66]

oh ok thanks.

He must have very dark and clear skies up there in Oregon too...

 

[tyqre]

i forgot to thank him amongst all the comotion!

 

[tyqre]

Yea, he was on top of Mount Hood to top it all off.

 

[McNugget801]

Stars will start moving after 30 seconds, so unless your going to do some trails use a high ISO and an open aperture.

ISO2000 F2.8 10mm Fisheye


Milky by Summit42, on Flickr

to make that image did the person do image stacking or was this 1 picture?

Its my photo
One 30second exposure
10mm fisheye
f2.8
ISO 2000
with a bit of noise reduction done in lightroom.

Yea, he was on top of Mount Hood to top it all off.

actually that's the rim of creator lake

 

[molested_cow]

In my experience, ISO is secondary. Shutter speed the primary element that you need to decide.

What kind of star shots are you trying to get? Star trails or just the clear milky way?

Then, what lens are you using? 20mm? 35mm? 300mm? Cropped or full frame?

The reason why these matters is because it will determine how much the stars move in the photo. For example, using a 20mm on full frame, I know that I cannot go above 30sec.

So after getting that straight, I can then play with ISO and aperture. If I want the foreground (landscape silhouette or objects like trees ) to be in the shot, I want lower aperture setting, that means I need to push ISO higher. If everything in the frame is far away, I can afford to have higher aperture and therefore lower ISO.

Generally speaking, I can get away with a nice exposure with the following set up.
20mm full frame at F5, 30sec, ISO 1600~2500


For light trails, I haven't gotten much chance to do it since I got my digital. So far I've been doing 10min exposures and stack them up. It's a tricky balance of noise. If you so shorter exposures, you need higher ISO or aperture to get the same exposure. That may mean more noise. If you do longer exposures, you can use lower ISO but you will get more of those colored specs (not sure what they are called). I am still learning it.

Also, there is no absolute setting. It depends on the environment condition and time of the day as well. It's all trial and error.

 

[tyqre]

Its my photo
One 30second exposure
10mm fisheye
f2.8
ISO 2000
with a bit of noise reduction done in lightroom.

actually that's the rim of creator lake

Oh, one exposure? Thanks that clears some things up.

 

[tyqre]

In my experience, ISO is secondary. Shutter speed the primary element that you need to decide.

What kind of star shots are you trying to get? Star trails or just the clear milky way?

Then, what lens are you using? 20mm? 35mm? 300mm? Cropped or full frame?

The reason why these matters is because it will determine how much the stars move in the photo. For example, using a 20mm on full frame, I know that I cannot go above 30sec.

So after getting that straight, I can then play with ISO and aperture. If I want the foreground (landscape silhouette or objects like trees ) to be in the shot, I want lower aperture setting, that means I need to push ISO higher. If everything in the frame is far away, I can afford to have higher aperture and therefore lower ISO.

Generally speaking, I can get away with a nice exposure with the following set up.
20mm full frame at F5, 30sec, ISO 1600~2500

For light trails, I haven't gotten much chance to do it since I got my digital. So far I've been doing 10min exposures and stack them up. It's a tricky balance of noise. If you so shorter exposures, you need higher ISO or aperture to get the same exposure. That may mean more noise. If you do longer exposures, you can use lower ISO but you will get more of those colored specs (not sure what they are called). I am still learning it.

Also, there is no absolute setting. It depends on the environment condition and time of the day as well. It's all trial and error.

Ok thank you, I'll take that into consideration, I'm using a crop sensor at 10mm with max aperture of f4. I'm not trying to get star trails, just detailed images of the night sky. So I should shorter exposures with open aperture and a high ISo, or it depends on conditions. I guess it depends on what's going on because that post above (which is awesome btw) had a 30sec exposure but if i used those settings outside my house the image would be really washed out.

 

[Garbz]

There's plenty of software out there for image stacking. I've seen several for mac as well but as I am a windows user you'll need to use the almighty Google to find some. Some software is free, other software is cheap so look around.

If you're after a single exposure with crystal clear skies and lake as above then stacking is one way to do it unless you have a camera with a mad low noise. I haven't seen Sw1tch post here yet but he's created some beautiful results with a D700 at high ISO and a 24mm f/1.4 but who has the money for that stuff right ?

I resort to stacking. And if you have a D700 and 24mm f/1.4 that will make stacking even better. Here's a result on a D200 with a kit lens, a combination known not for image quality, and actually known for pretty damn high noise: http://www.garbz.com/stars.jpg

The result is made up of 80 30 second exposures taken over a one hour period. Deep Sky Image Stacker's algorithm also takes into account additional frames for it's process so there were a further 30 frame shot a day later with the lens cap on in same settings. The resulting images were loaded into the software twice. Once star tracking was enabled which lined up all the images to get one final frame and once it was disabled which produced a noise free foreground (because I was too drunk to remember to crank out a 15min frame for the foreground) The resulting two images were combined in post.

The process is a bit of a rigmarole but the results can be very worth it. Mine have been getting better each time. A prime lens really helps and if you don't have one then you will need to come up with a method of eliminating distortion. The above image I took had distortion corrected in Lightroom and then the TIFs were stacked. However the better process would be to use a distortion free lens to begin with and use RAWs in Deep Sky Stacker due to the different ways the program treats RAW files from conventional RAW processors.

All in all, it's a process worth learning: http://ghonis2.ho8.com/100408horse.jpg here is an example shot by a guru using what can only be referred to as a cheap arse DSLR a Canon 350D, made of 30x 6min shots at ISO1600. His website is a throwback to the days of Geocities, and I'm surprised he doesn't use the old <BLINK> tag, ASTROPHOTOGRAPHY & DIGITAL IMAGING by Gary Honis but the result speak for themselves. The method does wonders for noisy cameras.

 

[tyqre]

There's plenty of software out there for image stacking. I've seen several for mac as well but as I am a windows user you'll need to use the almighty Google to find some. Some software is free, other software is cheap so look around.

If you're after a single exposure with crystal clear skies and lake as above then stacking is one way to do it unless you have a camera with a mad low noise. I haven't seen Sw1tch post here yet but he's created some beautiful results with a D700 at high ISO and a 24mm f/1.4 but who has the money for that stuff right ?

I resort to stacking. And if you have a D700 and 24mm f/1.4 that will make stacking even better. Here's a result on a D200 with a kit lens, a combination known not for image quality, and actually known for pretty damn high noise: http://www.garbz.com/stars.jpg

The result is made up of 80 30 second exposures taken over a one hour period. Deep Sky Image Stacker's algorithm also takes into account additional frames for it's process so there were a further 30 frame shot a day later with the lens cap on in same settings. The resulting images were loaded into the software twice. Once star tracking was enabled which lined up all the images to get one final frame and once it was disabled which produced a noise free foreground (because I was too drunk to remember to crank out a 15min frame for the foreground) The resulting two images were combined in post.

The process is a bit of a rigmarole but the results can be very worth it. Mine have been getting better each time. A prime lens really helps and if you don't have one then you will need to come up with a method of eliminating distortion. The above image I took had distortion corrected in Lightroom and then the TIFs were stacked. However the better process would be to use a distortion free lens to begin with and use RAWs in Deep Sky Stacker due to the different ways the program treats RAW files from conventional RAW processors.

All in all, it's a process worth learning: http://ghonis2.ho8.com/100408horse.jpg here is an example shot by a guru using what can only be referred to as a cheap arse DSLR a Canon 350D, made of 30x 6min shots at ISO1600. His website is a throwback to the days of Geocities, and I'm surprised he doesn't use the old <BLINK> tag, ASTROPHOTOGRAPHY & DIGITAL IMAGING by Gary Honis but the result speak for themselves. The method does wonders for noisy cameras.

Thanks for the tips. You sure do like those walls of text

 

[tyqre]

im just a little confused on what stacking actually is. Correct me if im wrong = Stacking is taking a bunch of the same photo all at the same time and combining them in a stacking program.

 

[Patrice]

You sure do like those walls of text

Sometimes good information requires more than a dozen words in a barely coherent sentence. Garbz has posted some good information leading you in the right direction.

Stacking is the combining of a number of images taken over a period of time. (You can't really take 40 or more images at the same time unless you happen to have 40 or more cameras.) The dark frames referred to are images of similar length exposure take at various times during the imaging session. These dark frame images are taken with the lens cap on. The purpose is to map out the irregularities of your sensor and then correct for them during the stacking process.

Look up 'Keith's image stacker'. It's a free stacker for Macs. You'll have to spend a bit of time doing some attentive reading and some practice before you are handy with this software.

Look on various astronomy websites and forums, many have a beginner astrophotography section.

 

[tyqre]

ok thanks.

 

[Garbz]

Thanks for the tips. You sure do like those walls of text

I don't read the forum every 5 minutes, so I miss quite a bit and have to reply in bulk

im just a little confused on what stacking actually is. Correct me if im wrong = Stacking is taking a bunch of the same photo all at the same time and combining them in a stacking program.

Stacking is a general term of combining images for certain post processing events. e.g. Exposure stacking combines images with different exposure to generate higher dynamic range, focus stacking combines images with different focal points to expand the depth of field, and this is just yet another form. All that changes is the algorithm.

If you're in an area with light pollution for instance one of the programs I've seen on the net stacks images together and selects the MAXIMUM pixel value in each for the final pixels. For star trails this has the advantage of being able to create trails of unlimited length without increasing the brightness of the sky.So you get results like this: http://farm2.static.flickr.com/1353/773160897_fae20200db_b.jpg which has a startrail length of 90 minutes, but in a light polluted city with an exposure of about 1minute. A single 90min exposure would have been nearly white in this case.

 

[tyqre]

f you're in an area with light pollution for instance one of the programs I've seen on the net stacks images together and selects the MAXIMUM pixel value in each for the final pixels. For star trails this has the advantage of being able to create trails of unlimited length without increasing the brightness of the sky.So you get results like this: http://farm2.static.flickr.com/1353/...e20200db_b.jpg which has a startrail length of 90 minutes, but in a light polluted city with an exposure of about 1minute. A single 90min exposure would have been nearly white in this case.

I am sorry i keep asking the same question over and over again but.. what your saying is that if i want to get a picutre where you can see the milky way from my house that look like this http://viewzone2.com/milkyway2.jpg(i dont live in a city but i live in the suburbs 15 miles away) I would have to take multiple 37 sec (maximum for my setup without trailing) exposures and combine then using the stacking software of my choice... Right?

 

[Garbz]

That is correct. Or you invest in a Camera with ludicrously low noise and an expensive wide aperture lens.

Although don't confuse this with the part of my text you have quoted. What I described above about stacking to a maximum pixel value will not make stars more visible, it simply ensures that the stars you can see can be trailed without blowing out the sky.

If you can't see the milky way when you look up then no amount of camera work can help you.