Red streaks on long exposure shots

Had some fleeting sunlight in Snowdonia today and shot a few long exposures (10 stop). Noticed when looking at them on the PC they have red streaks runing vertically...is this beacuse I stupidly forgot to use the viewfinder cover? Here's a crop of one of the shots

Very likely. Light enters the viewfinder, bounces around the pentaprism/pentamirror, and although the mirror is raised, I believe that light can sometimes leak past it.

I would say it's most definitely light leakage through the viewfinder Simon. I've had this before, but horizontally, not vertically.

Regards
David

Thanks guys, thought so...the sun was pretty much behind me too so nicely lined up with the viewfinder, another thing to make sure I remember next time

Simon

Hi Simon... Pretty definitely sunlight leakage... I use a bit of cut up credit card that I slot into the eyecup... Does the trick nicely (and keeps the bank manager happy)...

Best

The daft thing is I have two eyepiece covers in the bag, just forgot this time, hopefully the last

Simon