distance between gg and lens? at DVinfo.net

Dogus Aslan · November 21st, 2004, 05:01 PM

hi gang..

i am 1 week close to testing my "very slow progressing homemade mini35 design (due to my exams at school)"...

i am using a 1.4 pentax slr lens..i must keep a CONSTANT distance between th ground glass and slr lens...which is 45 milimeters in other words 1,7578 inches...i am wondering does this distance change in different brands of lenses??..or lets say i want to use a 35mm lens...?

any one have any idea about this..?and is the length i am talking about called focal length ?

cheers

Valeriu Campan · November 21st, 2004, 08:32 PM

You are looking at the "flange distance". A table for various stills cameras is here:
http://www.graphics.cornell.edu/~wes...-register.html.

Dogus Aslan · November 22nd, 2004, 11:19 AM

yeah valeriu thats what i was looking for...do u have any idea from which point to point do we calculate...is it from the bayonet to the lens where it touches the bayonet?

Valeriu Campan · November 22nd, 2004, 03:54 PM

AFAIK it is measured from the body to the film plane or from where the lens and body make contact.

Dogus Aslan · November 22nd, 2004, 04:42 PM

just what i wanted thanx pal...

Richard Mellor · November 23rd, 2004, 03:49 PM

this is what I use in the static adapter to get a perfect focus to the ground glass.http://www.thorlabs.com/ProductDetai...roduct_ID=1486

Dogus Aslan · November 23rd, 2004, 08:44 PM

screwed (adjustable) flange distance was what i had in my first design..but when i speeded up the gg i saw vibration and it caused the ground glass to move milimeter by milimeter very slowly...i am now making another design with fixed flange distance...

November 21st, 2004, 05:01 PM	#1
Dogus Aslan Regular Crew Join Date: Apr 2004 Posts: 56	distance between gg and lens? hi gang.. i am 1 week close to testing my "very slow progressing homemade mini35 design (due to my exams at school)"... i am using a 1.4 pentax slr lens..i must keep a CONSTANT distance between th ground glass and slr lens...which is 45 milimeters in other words 1,7578 inches...i am wondering does this distance change in different brands of lenses??..or lets say i want to use a 35mm lens...? any one have any idea about this..?and is the length i am talking about called focal length ? cheers

November 23rd, 2004, 03:49 PM	#6
Richard Mellor Major Player Join Date: Nov 2003 Location: cambridge ma Posts: 247	focal plane this is what I use in the static adapter to get a perfect focus to the ground glass.http://www.thorlabs.com/ProductDetai...roduct_ID=1486

November 21st, 2004, 08:32 PM	#2
Valeriu Campan Major Player Join Date: Mar 2004 Location: Melbourne, Australia Posts: 223	You are looking at the "flange distance". A table for various stills cameras is here: http://www.graphics.cornell.edu/~wes...-register.html.

November 22nd, 2004, 11:19 AM	#3
Dogus Aslan Regular Crew Join Date: Apr 2004 Posts: 56	yeah valeriu thats what i was looking for...do u have any idea from which point to point do we calculate...is it from the bayonet to the lens where it touches the bayonet?

November 22nd, 2004, 03:54 PM	#4
Valeriu Campan Major Player Join Date: Mar 2004 Location: Melbourne, Australia Posts: 223	AFAIK it is measured from the body to the film plane or from where the lens and body make contact.

November 22nd, 2004, 04:42 PM	#5
Dogus Aslan Regular Crew Join Date: Apr 2004 Posts: 56	just what i wanted thanx pal...

November 23rd, 2004, 08:44 PM	#7
Dogus Aslan Regular Crew Join Date: Apr 2004 Posts: 56	screwed (adjustable) flange distance was what i had in my first design..but when i speeded up the gg i saw vibration and it caused the ground glass to move milimeter by milimeter very slowly...i am now making another design with fixed flange distance...