Circles on photos

Carousels Spin

Carousels Spin

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If you look at the top left corner, there are circles that I assume are some sort of flare. What I can't work out is how I got them. They only seemed to happen when I was using filters, specifically polariser and 10 stop ND; they didn't happen with just the ND or just the polariser, only the two together. Why would it happen, and any way to avoid it in the future?
 
Could be dirt on the filter. Very tiny specks with backlight have caused similar effects for me.
 
At this size, the spots don't look markedly aperture-shaped. I'm tempted to concur with Andrew. Muck on a filter surface (or two) causing unwanted reflections ...

Tempted to say that it serves you right for using all those gizmos .... but then I won't be popular, will I?
 
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Did you use a lens hood?
 
Carousels Spin said:
View attachment 249714

If you look at the top left corner, there are circles that I assume are some sort of flare. What I can't work out is how I got them. They only seemed to happen when I was using filters, specifically polariser and 10 stop ND; they didn't happen with just the ND or just the polariser, only the two together. Why would it happen, and any way to avoid it in the future?
Click to expand...

Everything I recall reading in the past is against stacking filters.

I surmise that this particular combination is creating internal reflections between the two.....how to resolve??? Purely thinking out loud ~ would it happen if you stacked them in the opposite order, would it happen if you used an appropriate lenshood???

Carousels Spin said:
That was my thought too, cleaned both thoroughly but couldn't see anything on either of them. Happened after the cleaning too.
Click to expand...

See above.......cleaning them will not overcome the potential of internal surfaces reflections!

If the lenshood is not providing sufficient shading, perhaps a "flag' held far enough out of frame but still angled well to stop the flare?
 
Box Brownie said:
Everything I recall reading in the past is against stacking filters.

I surmise that this particular combination is creating internal reflections between the two.....how to resolve??? Purely thinking out loud ~ would it happen if you stacked them in the opposite order, would it happen if you used an appropriate lenshood???



See above.......cleaning them will not overcome the potential of internal surfaces reflections!

If the lenshood is not providing sufficient shading, perhaps a "flag' held far enough out of frame but still angled well to stop the flare?
Click to expand...
That would all make sense, and given it only happened when I put the two together I figured it would have something to do with the interaction between them.
 
I remember using a polarizing filter to bring out stress patterns in plastic some years back, I suspect what your seeing is the polar filer reacting with the ND.
Dont know if it'll make any difference but just out of couriousity try a shot with the pola filter on the outside. Just wondering if will change anything.
 
droj said:
At this size, the spots don't look markedly aperture-shaped.
Click to expand...


Sorry to disagree but they do look to be a rounded 7 sided shape to me so may well be aperture related.

When you stacked the filters, did you make sure that no light could get between them?
 
It is a fact that flare can be easily introduced. Flare is not only the obvious circles etc. but also can be a more general reduction in contrast. The key things to avoid flare is to always use a lens hood and never stack filters. I personally use no filters because I have carried out a number of experiments and can see the effects of flare. Of course in some situations using a single filter and a lens hood, the deterioration of the image should be minimal. You need to be particularly wary if there is a strong light source in front of the camera (even when not directly being captured). Examples of this are obviously the sun but also studio flash.

It is easy the measure the effect as well. The size of a Raw file is dependent on the detail; check your Raw files and you will see how much they vary. By taking shots with and without filters and lens hood, I can see that the Raw files taken with the filter(s) are from 3% to 10% smaller in size. Anything above 5% is very obviously softer when comparing the two images. When I gave a talk on this to my club, some were still sceptical but others later admitted that they now always use a lens hood and many now only use filters when thought absolutely necessary.

Dave
 
As above. Never use any filter unless you absolutely need to - except for polarisers, every filter effect can be created in post processing so there's no point in reducing the quality of the shot by fitting a filter, and never stack filters.

The most useful, and most under-rated accessory of all time is an effective lens hood.
 
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