Sunday, September 23, 2007

Canon 40D Night Time Exposure Tests: Part One

For the past five years, I've been using a Canon D60 for all of my night time work. When it was first introduced, I believe it was the only digital camera capable of shooting a whopping four minutes (under cool temperatures) without producing unacceptable levels of noise. Since then, sensor technology has improved. Clean exposures of up to ten minutes without noise reduction are not uncommon. And longer exposures of up to one hour, using in-camera noise reduction, are also possible.

(Click here to see the 100% crops taken at various long exposure intervals)

Last month Canon introduced the EOS 40D, the forth-generation replacement for the D60 (don't be confused by the naming conventions... this lineage went D30, D60, 10D, 20D, 30D, 40D). Last night I conducted some long exposure tests with the 40D. The subject isn't interesting, but I didn't have time to drive somewhere more interesting and start jumping fences.

I've uploaded the various 100% crops to this Flickr set, which also includes some daytime ISO tests. The shooting parameters are in the title of each shot.

Since my preferred ISO setting for night shooting has always been 200, I took most of these shots at ISO 200 over 3, 6, 9 and 12 minute exposures. I also had time for one 3-minute ISO 100 exposure to determine the difference between ISO 100 and 200 at long exposure.

Keep in mind that you can't directly correlate daytime ISO comparisons to long exposure night shots because the noise increases as the duration of the exposure increases (it's also effected by the temperature of the sensor). I may add more examples of different ISO/exposure combinations (along with in-camera noise reduction and Noise Ninja post-processing) in the future.


Blogger falmanac said...

"the noise increases as the duration of the exposure increases" Are you sure of that? Never saw it written anywhere before, concerning digital.

5:25 PM  
Anonymous Anonymous said...

I'm glad that you did these tests, but how about an overview on how this performs versus other cameras in your opinion, if it lived up to expectations, etc?

1:01 AM  
Blogger Andy Frazer said...

falmanac... Yes, I'm very sure of that. It's the biggest obstacle that digital night photographers have to learn to live with. Again, by "night photography", I'm referring to exposures of minutes, not seconds. There are entire pages dedicated to handling and controlling long exposure digital noise. In fact, that is the reason that all new DSLR's have built-in "long exposure noise reduction" capability.

Most DSLR's will generate noise by the time you get to 6 or 8 minutes. Without noise reduction, you can't go beyond that limit.

10:48 AM  
Blogger falmanac said...

Ain't that something? I'd just as soon crank up the ISO, but to each his own. Which leads me to wonder, is anybody else thinking about swapping their Canons for a new Nikon?

4:34 PM  
Blogger Andy Frazer said...

Falmanac... Once you get into the range of shooting longer than a minute (or so), cranking up the ISO will actually generate more noise than taking a longer exposure.

8:28 PM  
Blogger falmanac said...

Ah, that explains it: I shoot reletively short (1/15 etc) at high ISO's, so it's not something I've ever encountered. I guess I skipped that part of the instructions!

10:11 PM  
Anonymous Anonymous said...

i am going to do some long exposure tests as soon as this cloud cover breaks (probably thursday) but in my playing around in the house i have found that an iso 100 image at 32 min is beautiful (once you crank up the color noise reduction in lightroom).

i'll let you know how they come out...

2:58 AM  
Anonymous Anonymous said...

where do you set the configuration for long exposures? The max i have seen so far is just 30 seconds. Thanks..

4:02 PM  
Anonymous Anonymous said...

I am interested in night photography and recently went over the 40d but as of yet cannot get an exposure over 30 seconds.
How does one go about doing such long exposures?

8:32 PM  
Blogger Tim H said...

Alan, I have a 40D and I'm fairly new to it. Sorry for this newbie post/question but how can I extend my exposure times longer than 30" ? I haven't been able to figure out how yet, and I think I've tried! LOL

Can you point the steps to me, or where I can read about doing this with the 40D? It's probably something simple that I've overlooked...

Tim H

6:42 AM  
Blogger Tim H said...

Ah never mind, I think I found placing the camera on BULB mode, and using my remote I can lock the shutter manually for the time I want to try.


7:30 AM  
Anonymous Anonymous said...

Andy, thanks for this. Long exposure are some of the most rewarding landscapes I've mustered up. In fact I'm looking into the Canon Timer Remote to see if I can't improve the results and get rid of my elastic/cardboard rig that I use now to hold down the sh. release. Thanks for these tips, they are very useful, I wondered what the camera was processing for so long!

8:54 AM  
Anonymous pressure vessels said...

Nice article. Thanks for the info. Love the notes on night photography. great stuff.


9:29 PM  

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