View Full Version : Anyone had this problem...?


Leo Mandy
May 23rd, 2005, 04:54 PM
Ok, I have a new GG and it looks great. The image is huge and with great detail. BUT, when I put my DV camera in front of it, it get something like Vignetting, even though the picture on the GG is about twice the size as image the camera is seeing. I don't understand it! Any ideas?

Daves Spi
May 24th, 2005, 04:17 AM
Ok, I have a new GG and it looks great. The image is huge and with great detail. BUT, when I put my DV camera in front of it, it get something like Vignetting, even though the picture on the GG is about twice the size as image the camera is seeing. I don't understand it! Any ideas?

Damn, I know this very good. If I look on GG by eye, I have nice image, from corner to corner... But if I look through camera, vignetting shows up... I think, its because the light from primary lens is going like this < and light coming to your camera must be like this > :) so, if < meets >, center become strong and corners are dark... Sometimes helps to put camera enough far from GG and zoom on it, also condenser would help...

Leo Mandy
May 26th, 2005, 08:40 PM
What condenser are you using if you don't mind me asking? You stuff looks great!

Daves Spi
May 27th, 2005, 01:54 AM
What condenser are you using if you don't mind me asking? You stuff looks great!Thanks. Note, that in some shots I'm using Maxwell and in some Nikon. Its two different setups. But... Take a look here http://www.dvinfo.net/conf/showthread.php?t=43377&page=2&pp=15, where you will find tests Nikon vs Maxwell and make a decision. In fact looks very similar.

This is Nikon focusing screen which I used in test :
http://web.datriware.com/gfx_photos/articles/p859.jpg
And this is condenser I used to get really corner to corner image 36x24:
http://test.datriware.com/con.jpg
Corner to corner in lowlight (midnight, two 20W fluor bulbs):
http://web.datriware.com/gfx_photos/articles/p864.jpg
And direct sun:
http://web.datriware.com/gfx_photos/articles/p877.jpg

Leo Mandy
May 28th, 2005, 08:43 AM
So Dave,

Did that solve your problem with the darkness around the edges? Those focusing screens that you and Dan are using are expensive - so I am looking to do something similiar but on a cheaper scale. Any ideas?

Daves Spi
May 29th, 2005, 12:59 PM
So Dave,

Did that solve your problem with the darkness around the edges? Those focusing screens that you and Dan are using are expensive - so I am looking to do something similiar but on a cheaper scale. Any ideas?

Yes... use the nikon screen... Do not know for how much is new one, but can be bought for $10 at bazaar here... Look once more to test I post you, on one side is expensive fresnel and on the other is cheap focusing screen. I think this is what you are looking for...

Leo Mandy
May 29th, 2005, 01:09 PM
Ok, so the Nikon is double-sided then? Is there a certain name brand or model for them - the reason I am asking is that if I get an older nikon screen, does it have the same properties?
I will look for one - I wish they were as cheap here in Canada!

Daves Spi
May 29th, 2005, 01:34 PM
Ok, so the Nikon is double-sided then? Is there a certain name brand or model for them - the reason I am asking is that if I get an older nikon screen, does it have the same properties?
I will look for one - I wish they were as cheap here in Canada!

This http://web.datriware.com/gfx_photos/articles/p859.jpg is the nikon FS. On one side is GG, one the second is condenser. It works well for 24x18. If you want to take 36x24, you can place another condeser between FS and camera. In fact it can be some strong magnifier. This worked for me and my camera.

Matthew Kent
May 29th, 2005, 07:26 PM
So from what I understand, you are using a non-static system that involves a nikon/maxwell screen and condensor? Could the Maxwell or Nikon condenser be used with the Agus35 system?

I'm currently at a plateau with my DOF system, and purchased a condenser to remove the vignetting, but unfortunately have a very subtle and noticeable amount of barrel distortion that I'm not happy with.