I tried something different this weekend and I am trying to understand what went wrong. I was playing around with the filters and I stacked a 10IR PRO (Format-Hitech) with a 0.3 and 0.6 ND from LEE. The result was very near to what I was expecting. However, you will notice that that the top left part of the image was full of sort of circular dots. I am aware that shooting at f22 (i was using 16-35 f4) will bring every single dust in the sensor, but I am intrigued by those circular spots. The sensor was cleaned recently so I am not sure what is that and what could have possibly have caused the issue. My filters are kept in a clean pouch and I also clean the filter after usage, specially on the beach. I also checked the lenses and it was perfectly clean. It wasn't raining, just a bit "beach fog".
Please see the image below.
what could possibly have caused the issue? I know I can try and fix it in photoshop, just trying to avoid it next shooting.
Reflections would be my guess as well. That's a lot of lens surfaces (were they all multi-coated?) not to have some impact. I wouldn't expect dust on the objective end to be very visible (it might reduce contrast), but at F22 you've got all sorts of strange things happening where small areas of dirt or defects can show up.
There also seems to be a couple of arcs that are in that corner as well, were they really in the sky? Or is that part of the problem?
Is it possible these were really part of the sky? That's a long exposure, right?
Reflection were also my first thought. it might be that 3 filters can cause it, I really don't know. Also, they are different manufactures so they use different material etc. They are not coated. And the circles are not patterns in the sky because this is a long exposure shot (about two minutes something) it is a shame honestly, I quite like the shot.
>Linwood, > >Reflection were also my first thought. it might be that 3 >filters can cause it, I really don't know. Also, they are >different manufactures so they use different material etc. >They are not coated. And the circles are not patterns in the >sky because this is a long exposure shot (about two minutes >something) >it is a shame honestly, I quite like the shot.
Look at the structure (for want of a better word) at about the 10 oclock position just off that hatch on the left. It's not completely unlike some of the structures on the top left. I wonder if it's not cloud motion/formation in higher or lower levels that just happened to look like bubbles/reflections?
Did you have other similar shots with similar problems in the top left (or in one area)?