200mm Quantary used with Nikon D70

[lightcarver]

Ok, this is odd. I've been experimenting with night shots, and I've left the

lens open for say...30 mins with the f-stop either at F11, or F13, and out of

5 of the pictures I snapped, 2 had these really weird pink spots show up on

the top left hand corner of the image. No idea where this comes from. It's

pitch black in my backyard at night. You can't even see your hand in front of

your face, so...no light polution. Not even from a neighbor's porch light.

Anyone got any ideas?

[aardvarko]

show us

[MichaelChang]

Donald, hard to say without seeing the offending images but sounds like an issue of in-camera noise reduction switched off - or if not intentionally switch off, batteries ran dry before acquiring dark frame.

[aaron l]

With an exposure that long, the sensor heat will add pink blobs to your photos. You have to turn on in-camera noise reduction. It will double the time of your shots but the pink blobs will be eliminated.

 

If you do this shooting routinely, take a shot with the lens cap on in the dark for this amount of time as your reference shot. Then shoot the same times as your reference photos. Then come back and subtract the black/pink blob frame from the shot frame in PS. Google this technique, it works really well.