Filter Questions

[Michael_2010]

Recently I ordered the Cokin filter holder, a couple of adapters and some gradient ND filters. My first go at using them was a sunset on my 10-22mm. I wound up with orbs of light bouncing around all over the frame and in one instance I had duplicate images in some areas.

I decided it had to do with the ultra-wide, so this morning I put it on my 50mm. Once again orbs of light are duplicating across the frame. No other filter was on the lens. I did stack two of the ND filters in the holder trying to prolong the exposure.

What gives with this situation? Is this a common problem, or is it me?

[Nicole]

I haven't actually had that problem, even with stacking multiple filters. Well, not quite so pronounced. I had some light reflections when I used a grad ND and the sun was very predominantly in the shot, but that's not surprising to me since I was shooting right into the sun and flare is pretty much inevitable.

That said, it sounds like standard flare and associated filter issues. But aside from sunset, could you give a little more detail about how you were shooting? Was the sun above the horizon? Where was it in your frame? Did you have any other filters on your lens aside from the Cokin ones? I'm just wondering if there's something external causing it since I've never had such pronounced problems with the filters.

[Michael_2010]

The best way to explain it is to show some examples. I will find one from each separate outing and be back shortly.

Back with examples.......
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I don’t really care for either of these images for a variety of reasons, so I’m not interested in trying to salvage them. I’m just curious about the use of the Cokin filters.

This one was taken using a Canon 10-22 set at 22mm, Av f/13.0. There is some type of phantom image of the sun and the sailboat. After seeing these I remembered that I had left a UV filter on the lens.



The next one was taken using the Canon 50mm at f/11. I made sure there were no other filters on the lens and that the Cokin filters were clean. Used a combination of the 9 and 6. Little orbs of light are still bouncing around within the image.



What do you make of that?

[Nicole]

Ok, yeah, so the first one you had the UV filter on? I'm guessing that's what caused that double up. With strong light sources and a UV filter on I've had similar issues.

With the second, that doesn't look wholly unexpected to me given that you were shooting so directly into the sun. At least the bits of flare that are between the weeds. I'm not quite sure why the double reflection of the sun though. That being said though I'm not sure that I've stacked filters shooting into the sun before, so it could be that.

For comparison, shooting right into the sun using 1 Cokin Grad ND. Notice there's a bit of flare around the sun, but that was really expected, and it's pretty localised. But I'm also fairly certain I cloned out the characteristic green flare I tend to get on the 10-20mm shooting into the sun.



But shooting not quite into the sun with 3 filters stacked (mind you, this is a kind of terrible photo, but it is one shooting almost into the sun with stacked filters):



So I'm not experiencing the same sort of flare / reflection in my shots that you are in yours. So call me perplexed as to what's causing it!

[Michael_2010]

This is one of those situations where I just need to find a comfortable location and start taking shots with each filter at various angles off the sun to see what is happening.

One other thing I noticed was that one of the filters was very dirty straight out of the box. I didn't give that a thought until I got home that night and some of my shots looked like I had been in a rain storm with dark grayish spots all over the frame. I thoroughly cleaned them and have not seen that problem again, but the weird ghost lights are a little too unpredictable for my liking. What if I had been in a once in a life time situation thinking I just got the mother of all shots then discovered the filters ruined it? *argh*
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As an aside, I also learned that at 10mm you can actually get a pretty good shot of the Cokin filter holder in action. lol Ruins the picture, but what a field of view for that lens!!!