GG...should the ground side face the lens or the camera? at DVinfo.net

Phil Bloom · October 30th, 2006, 09:08 AM

if so, what happens if you have it the other way around?

My adaptor has the ground side facing the camera...

Toenis Liivamaegi · October 30th, 2006, 09:49 AM

It should be fine even with frensel focusing screens.
Lens flange to focal plane distance should be readjusted.

T

Phil Bloom · October 30th, 2006, 09:56 AM

It's just all I have read on forums, web pages say the ground side should face the SLR lens...I was wondering what the difference would be...

I have a permanent film of grain over everything I shoot under all sorts of different lighting conditions, camera settings, lenses etc...trying to work out what the culprit is

Giroud Francois · October 30th, 2006, 12:09 PM

since you are trying to capture the maximum of light coming from the lens, i think the grounded side must face the SLR.
your picture will be created at the best place (a flat, matte surface) and the light will not have to travel thru the glass.
if you use a plano convex lens to act as GG+condensor, you even will get the best setup, since the light coming from the GG goes directly to the right direction.
if you a doing the reverse, i see several issues.
the light coming from the SLR could reflect on the shiny,non-flat face of the lens.
having a coated lens would help.
if the light has to go accross the lens before forming the image, you do not really know what will happens, especially with unknown lens, or when you change the SLR lens. Again creating the image on a flat surface is the way it works in a camera, and it is the way lenses a built for.
The only drawback of having the gg facing the SLR, is dust protection.
If you have to add another layer of glass to protect it, you go back to the issues mentionned above.

October 30th, 2006, 09:08 AM	#1
Phil Bloom Trustee Join Date: Aug 2006 Location: London UK Posts: 1,939	GG...should the ground side face the lens or the camera? if so, what happens if you have it the other way around? My adaptor has the ground side facing the camera... __________________ Philip Bloom Cinematographer, Director, Filmmaker www.philipbloom.net

October 30th, 2006, 09:56 AM	#3
Phil Bloom Trustee Join Date: Aug 2006 Location: London UK Posts: 1,939	It's just all I have read on forums, web pages say the ground side should face the SLR lens...I was wondering what the difference would be... I have a permanent film of grain over everything I shoot under all sorts of different lighting conditions, camera settings, lenses etc...trying to work out what the culprit is __________________ Philip Bloom Cinematographer, Director, Filmmaker www.philipbloom.net

October 30th, 2006, 09:49 AM	#2
Toenis Liivamaegi Major Player Join Date: Nov 2005 Location: Tartu, Estonia Posts: 579	It should be fine even with frensel focusing screens. Lens flange to focal plane distance should be readjusted. T

October 30th, 2006, 12:09 PM	#4
Giroud Francois Inner Circle Join Date: Feb 2004 Location: switzerland Posts: 2,133	since you are trying to capture the maximum of light coming from the lens, i think the grounded side must face the SLR. your picture will be created at the best place (a flat, matte surface) and the light will not have to travel thru the glass. if you use a plano convex lens to act as GG+condensor, you even will get the best setup, since the light coming from the GG goes directly to the right direction. if you a doing the reverse, i see several issues. the light coming from the SLR could reflect on the shiny,non-flat face of the lens. having a coated lens would help. if the light has to go accross the lens before forming the image, you do not really know what will happens, especially with unknown lens, or when you change the SLR lens. Again creating the image on a flat surface is the way it works in a camera, and it is the way lenses a built for. The only drawback of having the gg facing the SLR, is dust protection. If you have to add another layer of glass to protect it, you go back to the issues mentionned above.