Low light/night problems with new Canon 6D (Page 3): Had you used the same lens as they used, you might have achieved the same or possibly better results. It is NOT the camera. I have...

PhotosBySteve

bobwalder wrote:

Just purchased a 6D so getting to know it. I took... (show quote)

Had you used the same lens as they used, you might have achieved the same or possibly better results. It is NOT the camera. I have had great success shooting night sky with my 6D and a 15mm f/2.8

bobwalder

mjmoore17 wrote:

I have found the Canon 6D to be a very good camera for the use that you described. Here is an example of Milky Way with 6D and a Canon 2.8 lens.

Beautiful image. Can you give me the focal length, ISO and exposure details?

bobwalder

JimH123 wrote:

I am adding a picture I took tonight using a 14mm ... (show quote)

Thanks Jim.... can you explain what you mean by "stacking" please? How come such short exposures? Also wouldn't time lapse result in trails or indistinct or even multiple points for each star?

wesm Loc: Los Altos CA

amfoto1 wrote:

I'd guess that 98 out of 100 "camera problems" are no fault at all of the camera or lens... but are due to the user doing something wrong.

If you could post them, it would be very helpful to see one or more of the "faulty" images with EXIF still attached.

You mention 20 second exposures and that should always cause Long Exposure Noise Reduction to operate when it's set to "Auto" (or "Enabled"). Set to that, LENR should activate with any exposure of 1 second or longer.

Are you aware how LENR works? It's actually two "exposures" of the same length, one right after the other. The first is the "usual" exposure where the shutter opens and an image is recorded. The second that immediately follows is a "blank" that the camera does with the shutter closed, which it then uses to detect noise, which is then "subtracted" from the first image. So a 20 second exposure will take at least 40 seconds, for example. any exposure with LENR applied will take twice as long as it's setting on the camera.

That explains why your "exposures" were taking so much longer than the other people... they probably didn't have LENR enabled.(I would probably turn it off for star field shots, too.... but you should ask them.)

Here's the tricky part... If you forget what's happening and cancel the second "shutter closed" exposure for any reason (such as by turning off the camera), the camera will dispose of BOTH the LENR and the original image!

If you try to "light paint" during the LENR "blank" shot with the shutter closed, your efforts won't be recorded.

Generally speaking, the 6D is a very low noise/high ISO capable camera. One of the best. Should have been able to shoot without LENR, at at 6400.You might give it a try.

The main reason many night shooters use f/2.8 lenses is not necessarily that they use the lens wide open... In fact they may stop the lens down to an optimal f-stop for best edge-to-edge sharpness with the particular lens they're using. (You should test your lens to see what it's optimal f-stop is.)

Many users might choose an f/2.8 (or faster) lens for a brighter viewfinder. But with DSLRs, Live View and Exposure Simulation might be a good substitute.

I'd guess that 98 out of 100 "camera problems... (show quote)

I like this proposed explanation. Especially about not recording the light painting. I always have LENR turned off, based on others' advice.
I have gotten excellent results with a 16-35 f2.8, good results with a 24mm, and mixed results with a Sigma 20mm f1.4, all wide open, but I really think my problems with the Sigma were focus-related.

Thanks

JimH123 Loc: Morgan Hill, CA

bobwalder wrote:

Thanks Jim.... can you explain what you mean by "stacking" please? How come such short exposures? Also wouldn't time lapse result in trails or indistinct or even multiple points for each star?

That's the beauty of stacking. It aligns each image so that all the stars line up on top of each other. And I used 4 sec only because I wanted to preserve star colors. When you expose for too long a time, all the bright stars saturate and as saturated stars, they all appear white. If I can expose for a shorter period of time, the color can still be seen. Now the advantages are stacking are that the stars become more distinct and the background appears darker due to an increase in the signal to noise ratio of the image being made up of additional images. But the big thing is that noise goes down too. For any given image, there will be noise. On the next image, there is noise too, but the random placement of the noise means that they noise specs don't line up in exactly the same pixel positions. And as you add more and more images, the image quality goes up as the noise goes down.

To do this stacking, there is a free application called 'DSS' which stands for Deep Sky Stacker. I suggest only downloading from the actual site since there is no guarantee how clean a program is coming from some other URL: http://deepskystacker.free.fr/english/download.htm.

There are a ton of settings in DSS, but the settings all have a default and for the majority of things you might do, the default settings are fine. I also like to add 'Darks' which means that I just capture some additional images with the lens cap on, but same camera settings. What it does now is to locate the stuck at pixels and DSS uses that information to fix the DSS output so that these stuck pixels don't show up in the final result.

After DSS runs, it creates a file called 'autosave.tif'. I don't do any additional adjustment within DSS and go straight to Photoshop to stretch the 'autosave.tif' file. First thing to do is to go to adjustments and change 'mode' from 32-bits to 16-bits. And then I do 'curves' and then 'levels', perhaps over and over until I get the result I want. I also use a plug-in from RC-Astro called XGradient to make the sky be a consistant dark color.

I use version 3.3.4 and find that the next earlier version doesn't support my cameras.

Some of my efforts are done with telescopes, and some with cameras and camera lenses. Just to show that I may use a longer shutter time, I am attaching the results of a stack of 15 + 10 darks using an Olympus em5ii and a 400mm f5.6 old m42 Pentax lens. This gives an effective focal length of 800mm, but is useful to see what focal length is needed to see galaxies. But some are closer and some are farther away, so you see all types. This one is 15 images of 60sec each with ISO 1600.

And just for fun, an image of Markarian's chain which shows a ton of galaxies. With the 400mm lens (effective 800mm), you can see about 15 galaxies, but a bigger scope sees far more.

Finally what can be seen using a telescope. The scope has a longer focal length, and the camera is a CCD camera (Atik Infinity), and you get image #3. This was a 40 sec image stacked 40 times.

Hope this explains a few things.

M51, Whirlpool Galaxy
M51, Whirlpool Galaxy...

(Download)

Markarian's Chain
Markarian's Chain...

(Download)

m101
m101...

(Download)

bobwalder

JimH123 wrote:

That's the beauty of stacking. It aligns each image so that all the stars line up on top of each other. And I used 4 sec only because I wanted to preserve star colors. When you expose for too long a time, all the bright stars saturate and as saturated stars, they all appear white. If I can expose for a shorter period of time, the color can still be seen. Now the advantages are stacking are that the stars become more distinct and the background appears darker due to an increase in the signal to noise ratio of the image being made up of additional images. But the big thing is that noise goes down too. For any given image, there will be noise. On the next image, there is noise too, but the random placement of the noise means that they noise specs don't line up in exactly the same pixel positions. And as you add more and more images, the image quality goes up as the noise goes down.

To do this stacking, there is a free application called 'DSS' which stands for Deep Sky Stacker. I suggest only downloading from the actual site since there is no guarantee how clean a program is coming from some other URL: http://deepskystacker.free.fr/english/download.htm.

There are a ton of settings in DSS, but the settings all have a default and for the majority of things you might do, the default settings are fine. I also like to add 'Darks' which means that I just capture some additional images with the lens cap on, but same camera settings. What it does now is to locate the stuck at pixels and DSS uses that information to fix the DSS output so that these stuck pixels don't show up in the final result.

After DSS runs, it creates a file called 'autosave.tif'. I don't do any additional adjustment within DSS and go straight to Photoshop to stretch the 'autosave.tif' file. First thing to do is to go to adjustments and change 'mode' from 32-bits to 16-bits. And then I do 'curves' and then 'levels', perhaps over and over until I get the result I want. I also use a plug-in from RC-Astro called XGradient to make the sky be a consistant dark color.

I use version 3.3.4 and find that the next earlier version doesn't support my cameras.

Some of my efforts are done with telescopes, and some with cameras and camera lenses. Just to show that I may use a longer shutter time, I am attaching the results of a stack of 15 + 10 darks using an Olympus em5ii and a 400mm f5.6 old m42 Pentax lens. This gives an effective focal length of 800mm, but is useful to see what focal length is needed to see galaxies. But some are closer and some are farther away, so you see all types. This one is 15 images of 60sec each with ISO 1600.

And just for fun, an image of Markarian's chain which shows a ton of galaxies. With the 400mm lens (effective 800mm), you can see about 15 galaxies, but a bigger scope sees far more.

Finally what can be seen using a telescope. The scope has a longer focal length, and the camera is a CCD camera (Atik Infinity), and you get image #3. This was a 40 sec image stacked 40 times.

Hope this explains a few things.

That's the beauty of stacking. It aligns each ima... (show quote)

Awesome stuff - thanks Jim

bobwalder

JimH123 wrote:

To do this stacking, there is a free application called 'DSS' which stands for Deep Sky Stacker. I suggest only downloading from the actual site since there is no guarantee how clean a program is coming from some other URL: http://deepskystacker.free.fr/english/download.htm.

Dammit.... Windows only! :o(

JimH123 Loc: Morgan Hill, CA

bobwalder wrote:

Dammit.... Windows only! :o(

Went to another product, Sequator, but again, only for Windows: https://sites.google.com/site/sequatorglobal/download

I have another stacker program called Nebulosity. Checked, and it does support Apple: http://www.stark-labs.com/nebulosity.html Not free. $95
It is not as simple to use as DSS and requires marking stars to anchor to in each image so that they line up properly. It does allow for a demo download.