What causes this purple area

jwashburn

I looked around on the web for the problem and most people seem to have a purple color cast over the whole photo, this was happening in just a few areas when there was high contrast between light and dark. The long exposure combined with hard side light seemed to be the cause.

Other than changing shooting time of day or composition, is there a way to avoid it. Any ways to fix it with PS or Lightroom?

ritewinger

It could be the ND filter, many if not all can display these weird color casts. It is usually fixable in post.........

jwashburn

ritewinger wrote: »

It could be the ND filter, many if not all can display these weird color casts. It is usually fixable in post.........

I could fix it, if it was a color cast across the while image. Its just in one place though. Still wondering what causes it to be on only part of the image

kdog

It's lens flare, possibly exacerbated by the filter. I'm guessing you didn't use a lens hood. To avoid it you would have needed to shield the lens from direct light, or just avoid shooting all together in harsh light. Convert it to B&W. For extra credit, you could try a conversion tool like the one in PS and adjust the purple so it becomes the same tone as the green.

JC

Variable ND?

aj986s

Not sure if its related, but I've run into some similar results when shooting high ISO on my Canon G10 (1600, it's max available) . If the light is very low, the image moves towards a purple cast, which is challenging to offset in post-processing. I've come to the conclusion that there's just not enough color data available to work with. However, the image ends up looking decent in B/W processing; I'm guessing that B/W doesn't require as much data ultimately.

JohnDC

I have removed lens flare colors as kdog suggested by going into hue and saturation adjustments and just working on the problem color--reducing saturation and lightness of the problem color. "Selective color" adjustments can help, too. Regarding the non-uniform effect, variable ND filters are known to cause patchy problems because of the ways that the crossing polarizers work.

jwashburn

It ended up being light coming in from the viewfinder. I encountered it again the other day and shutting the little shutter thing on the viewfinder made it go away

Stumblebum

I tried my hand at night photography and in complete darkness got yellow and orange cast all over, and had no filter on trying to collect maximum light. In the past I have picked up rainbow colors as well trying to create star trails.

I guess next time I better find a way to block light from view finder. This happens during long exposures in dark areas or with ND filters. Post processing doesn't get rid of it completely and one has to resort to b+w.


Thanks for sharing what worked for you!

kdog

Stumblebum wrote: »

I tried my hand at night photography and in complete darkness got yellow and orange cast all over, and had no filter on trying to collect maximum light. In the past I have picked up rainbow colors as well trying to create star trails.

I guess next time I better find a way to block light from view finder. This happens during long exposures in dark areas or with ND filters. Post processing doesn't get rid of it completely and one has to resort to b+w.


Thanks for sharing what worked for you!

I'm assuming you shot these locally... that's light pollution from all our yellow street lights. Try setting a tungsten light balance and I bet it goes away. Better yet, shoot at Yosemite or Death Valley.

JonaBeth Russell

Looks like lens flare to me. As suggested, shield the lens with a hood or opt for a circular polarizer filter.

JohnDC

jwashburn wrote: »

It ended up being light coming in from the viewfinder. I encountered it again the other day and shutting the little shutter thing on the viewfinder made it go away

It did look like a light leak from the film days. Thanks for pointing this out.

Stumblebum

kdog wrote: »

I'm assuming you shot these locally... that's light pollution from all our yellow street lights. Try setting a tungsten light balance and I bet it goes away. Better yet, shoot at Yosemite or Death Valley.

Thanks Joel! Happy New Year to you! I have tried in back country to get night shots and have not succeeded. I got up from SJ for Lenoid meteor shower, went to Big Sur at 3:00 am and came up empty.

My hope is that once I crack the code on night shots, then the formula should hold in general for nights everywhere. Gonna keep trying though.....

I did go to Hawk Hill and loved the spot. I lack the standard zoom in my arsenal and it was "Bridge too far" for 16-35mm and too close for 100-400mm. Once I save up, I will invest in 24-70m. I think I also found the trail head for Kirby Cove. THANKS for your help!

Just so you know, due to winter solstice, the sun is sort of lined up with Pfeiffer portal in Big-Sur. I know you have posted some amazing shots of that as well and it has been my quest to shoot something like that. There also I felt standard zoom would have been the right option. This and couple more is what I got.....

http://stumblebum.smugmug.com/Landscapes/Golden-Staircase-to-Heaven/i-sL5LrMb/A

Low tide sucks. Also probably we don't have more than few days of this left.

Cheers,
Taz