September 20, 2014, 12:27:33 AM

Author Topic: 5d mark 2 long exposure processing time  (Read 3397 times)

jimy444

  • SX50 HS
  • **
  • Posts: 6
    • View Profile
5d mark 2 long exposure processing time
« on: March 04, 2013, 01:51:10 PM »
Hi Guys
i am facing a problem when using my 5d mark 2 during night shots
I am shooting at 5 - 10 - 30 seconds and bulb and it is taking as much time for the picture to display on the screen/finish processing as the exposure time

example if i set the exposure to 30 seconds it takes another 30 seconds for photo to appear
and the buffer is going full and making me wait after couple of shots.
Imagine doing it on long exposures, 100 secs each.. i can only shoot couple of shots and it will make me wait to finish precess before i can even shoot another one.

is this normal ?
are you facing such problems, i tried with a friends 5dmark 2 and it is going much faster. even with a 200 seconds exposure the photo is appearing the second the shutter closes, and it is a big problem as i shoot night skies and scenery to wait that long for each photo...

canon rumors FORUM

5d mark 2 long exposure processing time
« on: March 04, 2013, 01:51:10 PM »

neuroanatomist

  • CR GEEK
  • ********
  • Posts: 14424
    • View Profile
Re: 5d mark 2 long exposure processing time
« Reply #1 on: March 04, 2013, 02:01:21 PM »
That's the Long Exposure Noise Reduction setting - it takes a dark frame after the exposure, equal in time to the exposure, and subtracts that from the image.  You can turn it off, but then you'll have some thermal noise in the image.  Instead of using the in-camera long esposure NR, many astrophotogs take their own dark frame (just one of the proper duration) and subtract that from the each of the images in post.
EOS 1D X, EOS M, and lots of lenses
______________________________
Flickr | TDP Profile/Gear List

wayno

  • EOS M2
  • ****
  • Posts: 228
    • View Profile
Re: 5d mark 2 long exposure processing time
« Reply #2 on: March 04, 2013, 02:05:33 PM »
I've never chosen to use it and most of my work is night photography. The reality is that the amount of thermal noise is negligible in most instances. I suspect LR does some auto clean up of RAW files etc on import too (I used to see the odd hot pixel etc in JPG but never in RAW).


Don Haines

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 3190
  • Posting cat pictures on the internet since 1986
    • View Profile
Re: 5d mark 2 long exposure processing time
« Reply #3 on: March 04, 2013, 05:21:20 PM »
If you really want to find out if you should be using the function or not,  turn the long exposure noise reduction off, set the camera to your intended iso, put the lens cap on, and in a dark room take a picture of your intended exposure time.... that should be your noise....

If it is significant, leave the function on, if it isn't.... turn it off..

The best camera is the one in your hands

Mt Spokane Photography

  • Canon EF 600mm f/4L IS II
  • ********
  • Posts: 8682
    • View Profile
Re: 5d mark 2 long exposure processing time
« Reply #4 on: March 04, 2013, 09:20:07 PM »
Hi Guys
i am facing a problem when using my 5d mark 2 during night shots
I am shooting at 5 - 10 - 30 seconds and bulb and it is taking as much time for the picture to display on the screen/finish processing as the exposure time

example if i set the exposure to 30 seconds it takes another 30 seconds for photo to appear
and the buffer is going full and making me wait after couple of shots.
Imagine doing it on long exposures, 100 secs each.. i can only shoot couple of shots and it will make me wait to finish precess before i can even shoot another one.

is this normal ?
are you facing such problems, i tried with a friends 5dmark 2 and it is going much faster. even with a 200 seconds exposure the photo is appearing the second the shutter closes, and it is a big problem as i shoot night skies and scenery to wait that long for each photo...

People tend to turn on optional features because they sound useful.  But ... Make sure you know how they work, and what they will do.
Long Exposure noise reduction is a common one that falls in that category.  Its very useful if you are taking a extreme long exposure, say 10 minutes or more.  But, there is a additional 10 minutes or more wait to capture the noise that is subtracted from the image.

Don Haines

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 3190
  • Posting cat pictures on the internet since 1986
    • View Profile
Re: 5d mark 2 long exposure processing time
« Reply #5 on: March 04, 2013, 10:54:45 PM »

People tend to turn on optional features because they sound useful.  But ... Make sure you know how they work, and what they will do.
wise advice.

I tend to shoot astronomy with a 60D. When I first got the camera I did some test shots with the long exposure noise reduction on and off.... my conclusion was that it made the noise worse for the way I shot.

I redid the test tonight. The two pictures are the bottom right corner of two identical exposures, the first one being with noise reduction off, and the second with it on. Both shots are ISO800, 60D body, lens cap on, dark room. The post processing is the corner crop of the pictures and turning exposure up by 3.00 in lightroom. Note how the noisiest picture is the one with long exposure noise reduction turned on.... This is why I don't use it.

You would have to do the comparison on your camera at the iso and shutter speed you use to get meaningful results for you.
The best camera is the one in your hands

Alex

  • PowerShot G1 X II
  • ***
  • Posts: 70
    • View Profile
Re: 5d mark 2 long exposure processing time
« Reply #6 on: March 09, 2013, 05:06:45 PM »
I have found the same on my 1DX, the noise reduction often makes the noise worse

canon rumors FORUM

Re: 5d mark 2 long exposure processing time
« Reply #6 on: March 09, 2013, 05:06:45 PM »

RGF

  • 1D X
  • *******
  • Posts: 1273
  • How you relate to the issue, is the issue.
    • View Profile
Re: 5d mark 2 long exposure processing time
« Reply #7 on: March 09, 2013, 11:20:20 PM »
That's the Long Exposure Noise Reduction setting - it takes a dark frame after the exposure, equal in time to the exposure, and subtracts that from the image.  You can turn it off, but then you'll have some thermal noise in the image.  Instead of using the in-camera long esposure NR, many astrophotogs take their own dark frame (just one of the proper duration) and subtract that from the each of the images in post.

+1

jrista

  • Canon EF 400mm f/2.8L IS II
  • *******
  • Posts: 4547
  • POTATO
    • View Profile
    • Nature Photography
Re: 5d mark 2 long exposure processing time
« Reply #8 on: March 10, 2013, 12:21:54 AM »
Hi Guys
i am facing a problem when using my 5d mark 2 during night shots
I am shooting at 5 - 10 - 30 seconds and bulb and it is taking as much time for the picture to display on the screen/finish processing as the exposure time

example if i set the exposure to 30 seconds it takes another 30 seconds for photo to appear
and the buffer is going full and making me wait after couple of shots.
Imagine doing it on long exposures, 100 secs each.. i can only shoot couple of shots and it will make me wait to finish precess before i can even shoot another one.

is this normal ?
are you facing such problems, i tried with a friends 5dmark 2 and it is going much faster. even with a 200 seconds exposure the photo is appearing the second the shutter closes, and it is a big problem as i shoot night skies and scenery to wait that long for each photo...

The increased time is the built-in camera Long Exposure Noise Reduction (LENR). It exposes what is called a Dark Frame after the light frame, and that frame is used to subtract noise (assuming it works...in-camera LENR does not always work.)

If you are doing night sky astrophotography and want low noise results, it is better to handle noise reduction on your own. You can take your own dark frames, as well as bias frames, in addition to light frames, and combine them all with a tool like DeepSkyStacker. DSS will use multiple light frames to maximize SNR, and use a properly combined dark frame and bias frame to subtract the noise.

Light Frames are the full color exposures of the night sky. It is best to have as many of these as you can. A single light frame will be very noise, poor in contrast, low in SNR, and otherwise barely sufficient for a night sky photograph. Stacking two light frames produces better results with higher contrast, but you will still have a low SNR. It is best to shoot at least 20 light frames or more of the same stellar object to maximize SNR.

Dark Frames are exposed the same as light frames, only with the lens cap on. By "the same as light frames", I mean...EVERYTHING has to be the same. Shutter, Aperture, ISO, AND temperature. The temperature matters her because it affects noise. If you are shooting the sky on a very cold night, dark current will be lower than on a normal night, and noise will be lower than on a normal night. You can expose all dark frames after the entire sequence of light frames is done. It is best to have 16-20 dark frames to produce a master dark frame for that particular shoot. If you end up shooting 40, 60, 80 light frames, you still only need to have 16-20 dark frames.

Bias Frames are created at the fastest possible shutter speed, and the same ISO as the light frames. It does not matter what the temperature is. Again, it is best to have 16-20 bias frames to produce a master bias frame for that particular shoot.

Once you have a set of light frames, dark frames, and bias frames, you can stack them with a tool like DSS. Just give it all the files, and it will take care of the rest. It'll produce master dark and bias frames for you from their individual frames. It will then process the light frames...align them, apply the dark and bias frames, then stack them to produce a single, low-noise, high SNR night sky photo. Once you have the initial night sky photo...you are pretty much on your own to tweak the final outcome (which is actually quite a pain with DSS, you might end up better off by exporting the default output for tweaking in another program.)

The results of the above method should be far superior to single-shot exposures of the night sky, with or without in-camera LENR.
My Photography
Current Gear: Canon 5D III | Canon 7D | Canon EF 600mm f/4 L IS II | EF 100-400mm f/4.5-5.6 L IS | EF 16-35mm f/2.8 L | EF 100mm f/2.8 Macro | 50mm f/1.4
New Gear List: SBIG STT-8300M | Canon EF 300mm f/2.8 L II

canon rumors FORUM

Re: 5d mark 2 long exposure processing time
« Reply #8 on: March 10, 2013, 12:21:54 AM »