6 replies to this topic

[Jim Jones]

Hi experts:

 

I was shooting in Yosemite with my (still somewhat new) D610 yesterday. I tried doing some long exposure shots of about 30 seconds (ISO3200, f4.8) and got an unacceptable amount of red noise in the images. I've attached an example. This also happened when I went as low as ISO1000.

 

I was in an extremely dark area - pointed toward Yosemite Valley with no car lights or anything nearby. Oddly, I was able to use my D300 backup body and shoot the same shots from the same locations, no red noise.

 

I did read a suggestion somewhere else about turning the long-exposure noise reduction (LENR) on, but that presents another problem - I'd like to shoot multiple 30-60 second exposures and "stack" them to capture star trails, but that wouldn't be possible with the LENR on due to the amount of post-processing time it takes.

 

Any thoughts?

Attached Thumbnails

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[Brian]

Is the noise only occurring in the Red channel? Use Photoshop (or equaivalent) and set the red channel to zero.

 

It looks like a light leak- Possible? Viewfinder leakage?

 

Just thinking out loud.

 

Also- sensors warm up as they are running, and noise increases. I wonder if the firmware accounts for that.

[Adam]

I would start by checking to see if long exposure noise reduction will solve the problem, and take it from there.  Generally speaking it shouldn't be necessary for 30s exposures, but then again you are shooting at a fairly high ISO.

[Jim Jones]

It looks like a light leak- Possible? Viewfinder leakage?

Yep, I bet that's it. I said I was in a completely dark area...thinking about it more, that's not 100% accurate. I was standing in a parking lot near a tunnel. The camera was pointed TOWARD a dark area, but yeah...light very well could have come in the viewfinder. Geez I hope that's all it is! Thanks for the tips.

[RossCumming]

I was also going to suggest light leaking in through the eyepiece - your D610 should have come with a blanking plate specifically to be fitted over the eyepiece tp prevent light-leakage (but you have to remove the standard eyepiece part first. I keep my blanking adapter clipped on to the camera strap - it fits nicely on to the strap and has never fallen off - in fact I am more prone to loosing the standard eyepiece off the camera body than the blanking piece which is clipped on to the strap.....

[TBonz]

What standard eyepiece?    Lost them on both my D600s...Do have the AquaTech eyepiece that works with the cover, but it works fine with or without...I have the blackout covers in my camera bag if needed...

[Ron]

I think I would try to make sure I was completely shielded from any extraneous light sources... from any directions, before getting excited over this. Each time I look at the photo it reminds me more and more of a classic case of light pollution. Maybe try shooting from under a black umbrella next time.

 

--Ron