Need Help with aberation

[dougbenc 0]

Please help me...

 

I am using a Canon 7d with an ikelite housing and new dome port.. I have been getting a reflection or some sort of aberation in some of my frames. Sometimes it is on the left, sometimes on the right and sometimes it is nearly a complete circle... I am uploading two images. One has no problem and the other has the issue pointed out on the frame. I do not change the position of the lights or any other settings, but sometimes, it just doesn't happen at all. I keep the cones of the lights pointed away from the housing and I am sure that I am not getting any direct light hitting the housing...

 

Any help would be greatly appreciated.. Thanks, Doug

[twinner 5]

It looks to me like something reflecting of the camera or lens. Like a gold ring around the lens or shinny letters. Try covering that stuff up with some electrical tape or take a felt marker to it.

 

Todd

[Steve Williams 0]

Check out Stephen Frink's answer he wrote up a while back.

http://www.stephenfrink.com/sf-tips/200801...okina-workflow/

 

Cheers,

Steve

[PRC 2]

From back when I had an Ikelite I seem to recall that I tracked that down to being the joint line between straight section of the the port and the dome.

 

For me the only way out was to watch for it when shooting into a bright light source.

 

As in the second image over the first where the sun is coming into play.

 

Paul C

Edited February 26, 2010 by PRC

[james 0]

If your port has a clear body I would also recommend wrapping it in black tape - to keep out any stray light. The other recommendations are spot on.

 

Cheers

James

[tdpriest 115]

It looks to me as if the left-hand strobe is shining into the dome or the housing: only a little, but there is some backscatter as well as the annoying reflection. Pulling the strobe back a few inches, or using an extreme outward angle (you would be surprised at what works - I was!) will help. Even with metal housings this can be a problem as light creeps in through the dome port and reflects, often off lettering on the lens (but even black edges, like the teeth on a lens gear, can reflect bright light). It's a major problem with using an internal flash to trigger the external strobes, too.

 

Tim

 

[PRC 2]

Valid reply Tim, but when I had my Ike this occurred without a strobe - didn't try tape though - sounds like a good idea.

 

Paul C

[dougbenc 0]

I guess I need to do some more experimenting, but my strobes are definately pointed nearly 45 degrees outward now and are hitting the dome directly. One thing I noticed that seems quite a bit different from when I have the 15mm/1.4x on instead, is that the lens is very close to the dome. I have never gotten it with that combination. But with my Tokina 10-17, it seems I am getting it on one or both sides periodically. Even if I am pointed down or pointed up into the sun.. I wish the lens was much closer to the dome, it would probably take away whatever I am getting.. Thanks for all the input.. I will let you know if I figure it out..

 

 

It looks to me as if the left-hand strobe is shining into the dome or the housing: only a little, but there is some backscatter as well as the annoying reflection. Pulling the strobe back a few inches, or using an extreme outward angle (you would be surprised at what works - I was!) will help. Even with metal housings this can be a problem as light creeps in through the dome port and reflects, often off lettering on the lens (but even black edges, like the teeth on a lens gear, can reflect bright light). It's a major problem with using an internal flash to trigger the external strobes, too.

 

Tim

 

[ChrigelKarrer 52]

doughbenc,

 

i have the same problem with my Ikelite port for the Nikon 18-105mm VR lens and when i use it in wide angle mode because she retracts a bit.

I figured out that it is the light (ambient or flash) shining tru the transparent tube and reflecting on the inside of the glass port in front.

I just cut of the tip of a old black sock, pulled it over the tube of port and the reflection went away and as sideeffect i can pull the sock over the lens to protect it during transport.

It don't look very fancy but works very well...

I had a similar problem too with my Fuji E900 and it's Ikelite housing where a silver ring on the lens was creating reflections,

there i just painted the silver ring black using the old and famous sharpie.

 

Here a example of the reflections i got:

 

Chris Karrer

 

P.S. I don't have problems with the Ikelite 6'' dome port because my Tokina 12-24 with the diopter is quite near to the dome so that i can't catch any reflections.

Edited March 5, 2010 by ChrigelKarrer