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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Double Sun

Paul Kalbach

Paul Kalbach

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Does anybody know what would cause the sun to double in this image? Actually, there's a 3rd repeat off to the lower right. I've never seen a flare like this. I assume it has to do with the optics of the lens I used; a 500mm Century Tele-Athenar (Standard Arri Mount adapted to PL Mount). Could it be because I was stopped down to f22? Oddly, there was no usual black or purple spot in the middle of the sun. Shot through circular polarizer and Pancro ND.9+IR. Other parameters: build 17, 4K HD, 23.98 fps, ASA 320. It turned out to be an interesting effect in this shot, but I'd like to know how to avoid it if need be.
 
Is there anything like a mirror in this lens?

We only see the reflection on high contrast lights... it could be a inherent default of the lens wich would not be seen in normal light conditions???

The filter reflection is a good one to think about...

Patrick

PS: Salut Daniel!
 
Was your IR filter the first one in front?
 
The mirror-like Pancro ND+IR cut is certainly a possibility. There's no mirror in the lens that I know of. There is an internal gel filter holder which I've seen to cause artifacts when there's a gel in it, but it was not fitted with a gel and everything sealed around the filter slot and mattebox to avoid internal reflections.
 
f22

f22

i too think the filters are causing this - but keep in mind that...

f22 might also cause issues. the light starts scattering in the lens. better never to shoot at f22.

tanner
 
Evin Grant said:
This is from the Pancro/Pola combo. Use the Pancro alone and you should be fine.
Click to expand...

Thanks Evin, I didn't know that was a bad combo. I had another shot where specular highlights doubled up. Are there any issues using this combo on "normal" images?
 
Evin Grant said:
This is from the Pancro/Pola combo. Use the Pancro alone and you should be fine.
Click to expand...

...either that, or from the reflective coating on the front lens element. In that case get some sand paper and...:innocent:

...well, try different lens first and see if you still get the reflection.
 
Paul Kalbach said:
Does anybody know what would cause the sun to double in this image? Actually, there's a 3rd repeat off to the lower right. I've never seen a flare like this.
Click to expand...

It looks to me like internal reflections from within the lens elements itself, or maybe the filters, especially when you have such a long focal length lens. When you have such a hot spot on older less well coated optics....

I usually push the top of the mattbox on a shot like this and find you can make it go away...if it's filters. Some matteboxes even allow you to cant the trays.


jb
 
My guess is that it's the lens rather than the filter. With ghosting you usually get a ghost image for each lens element (I assume that's why it would appear worse on a zoom than a prime?)
 
My vote is the panchro reflection.

The "non-mirrored" side of these filters are highly reflective. Unless you use it by itself, expect to worry about this kind of ghosting.

I regret buying a set of panchros :-(
 
Hey all

We have new footage of our 1.2 ir+nd filter in action on our webpage/homepage-www.pancro.com(NO DOUBLE IMAGES OR SPECULAR LIGHT ISSUES )The afformentioned shots were done by Christopher Karcher-Principal / Creative Director KARCHER designs who did the initial field testing last spring. He was one of our first customers to purchase the IR+ND that we innovated last year/included in Evin Grants tests. Our filters work well if they are used correctly-Hope this helps!
 
Brian Dougherty(PANCRO) said:
Hey all

We have new footage of our 1.2 ir+nd filter in action on our webpage/homepage-www.pancro.com(NO DOUBLE IMAGES OR SPECULAR LIGHT ISSUES )The afformentioned shots were done by Christopher Karcher-Principal / Creative Director KARCHER designs who did the initial field testing last spring. He was one of our first customers to purchase the IR+ND that we innovated last year/included in Evin Grants tests. Our filters work well if they are used correctly-Hope this helps!
Click to expand...

What does "used correctly" mean?
 
We have seen some customer have more success than others depending on varying factors. Filter placement, mattes, french flags etc. We are currently doing more testing/consulting to provide a tested model for use. Like all art, it is subjective to the artist.
 
Brian Dougherty(PANCRO) said:
We have seen some customer have more success than others depending on varying factors. Filter placement, mattes, french flags etc. We are currently doing more testing/consulting to provide a tested model for use. Like all art, it is subjective to the artist.
Click to expand...

I think the success is less about the customer and more about the kind of glass being used.

The reality is that the "non mirrored" side of pancros are more reflective than any competitors filters. As such Pancro's require special attention when shooting certain subject matter.

I have followed all the rules;

Filter placement - yes, always the furthest from the lens.
Mattes - yes we use mattes to minimize the amount of light entering the matte box
French flags-yes we are always conscious of flares

There is nothing "subjective" about the ability of Pancro's to cause ghosting when you use it with another filter and there is a specular highlight in the frame.

I'd be glad to reproduce the problem for you anytime.

I think the solution would be to have the filter manufactured with a different kind of glass that was not as reflective on the "non-mirrored" side.

If you look through this thread

http://www.reduser.net/forum/showthread.php?t=9412&page=4

I said many good things about Pancro and was very excited about them as a solution to IR. After purchasing a set and using them in the field I have found them to be more of a worry, and in some cases impossible to use.

If anyone wants to buy a set...PM me first!
 
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