Problems Using 50D and Noise Reduction

[Ron Hillstromb]

  I was able to test my 50D tonight and had a problem where Noise Reduction would stop and down load begin with in about 5 seconds while in Bulb Mode again.  I changed USB cable but the problem persisted.  Then I set up my 60Da and it worked fine.  I had been using the Canon AC adapter for the 50D.  I switched to battery and the problem vanished.  I used the AC adapter again and when in Bulb mode and 30 seconds the download would start within 5 seconds of the start of the noise reduction sequence.  I changed from bulb to 30 second exposure and the noise reduction worked as expected.  Initially thought it may be and could still be a weak adapter power supply but should cause the same problem whether bulb or not.

 

  The 50D is placed into Bulb with the switch at the (M)anual setting.

 

Ron

[admin]

  I was able to test my 50D tonight and had a problem where Noise Reduction would stop and down load begin with in about 5 seconds while in Bulb Mode again.  I changed USB cable but the problem persisted.  Then I set up my 60Da and it worked fine.  I had been using the Canon AC adapter for the 50D.  I switched to battery and the problem vanished.  I used the AC adapter again and when in Bulb mode and 30 seconds the download would start within 5 seconds of the start of the noise reduction sequence.  I changed from bulb to 30 second exposure and the noise reduction worked as expected.  Initially thought it may be and could still be a weak adapter power supply but should cause the same problem whether bulb or not.

 

  The 50D is placed into Bulb with the switch at the (M)anual setting.

 

Ron

 

It's the adapter. BULB images and TV (or others) are not initiate the same way withing the Canon SDK.  They use completely different commands and the behave differently.

 

Hope this helps,

 

Guylain

[Ron Hillstromb]

Follow up to this.

 

  This morning I was able to replicate the problem I am having over and over again.  My goal was to find out when the component breakdown caused a problem with the Canon AC Adapter.  I did not have any problem until I set the mirror lock to 1 or greater then the Noise Reduction was cancelled somehow.

 

  I made exposures with and with out mirror lock on for about an hour and when the mirror lock was off the noise reduction exposure was completed.  Every time the mirror lock was set to on the noise reduction was not completed and download started within about 5 second.

 

  I have simple logs, (one 35 sec exposure with mirror lock off and one 35 sec exposure with mirror lock on), ready to send when you are ready.  I know that BackYardNIK is the hot topic now.  I don't want to take from that project and the process occurring now.

 

  I expect my 7D to be back soon from Canon and I will be back to the 60Da.  I can keep Mirror Lock turned off with my current setup and probably not have any ill effects.  This may be an inherent problem with the 50D like some of the other models have problems.

 

  Thank you for all of your work.

 

Ron

[admin]

Mirror lock... umm... I have to think about this one... it should work.

 

What confuses me is that with the battery ML works and with the AC it does not.  Which tells me the AC plays a major role <_>

 

Guylain

 

 

 

[s3igell]

While the interplay of SDK and Mirror Lockup and Battery vs AC are going to puzzle Guylain for a bit...

 

Most AP Imagers specifically Disable LENR (Long Exposure Noise Reduction), as its been shown that Calibrating Images from a Master Dark works better than the one-to-one in-camera subtraction of a LENR Dark from the accompanying Light Image.

[astroman133]

I don't use in-camera dark subtraction or mirror lockup, but I am actually not too surprised that if the mirror is locked up that in-camera dark subtraction are disabled.  My reasoning is that having the mirror down helps keep light from getting to the sensor when the dark is being taken, especially in a light-filled situation.

 

I strongly recommend disabling long exposure noise reduction (what I have called in-camera dark subtraction). Shoot RAW images and do your own dark subtraction.  You will get a better result be able to image more targets when the stars are out.

 

 

[Ron Hillstromb]

Thanks for the comments.

 

  I use the noise reduction because 95% of my imaging is from my Red zone light polluted front yard with a street light on the corner of my lot.  I really don't get serious about it and primarily use the imagers, both CCD and DSLR to be able what I can't see visually.  When I go to Dark Sky locations for the other 5% I get a little bit more serious but not a lot.

 

  I have done some more testing with the 50D this afternoon using internal batteries and found I had the same results.  I have sent log files to Guylain for him to determine the problem and probably include a fix , if is isn't SDK related, in 3.1.

 

  The mirror lock isn't crucial with the winds I have been having lately and my other pursuit, wildlife photography, is taking forefront now with Spring migration of various species of birds.  I am in the field about 5 day a week now until it is complete.  But when I get home and there are clear skies I try to get out.

 

  thanks again for your thoughts and comments.

 

Ron