Flange Distance

borsuk · 11-04-2011, 07:23 AM

Hello

Does anybody know the real flange focus distance of Pentax Q ? I've checked it myslef and my result is approx. 8.85mm instead of 9.2mm what all specifications claim. I' ve heard that adapters available on ebay focus beyond infinity. so they have to be too thin. Maybe my camera body is faulty? What are your opinion?

Last edited by borsuk; 11-04-2011 at 07:35 AM.

Zygonyx · 11-04-2011, 08:34 AM

Hello, have you included the IR filter's proper flange to sensor ?

Wheatfield · 11-04-2011, 10:50 AM

As noted, unless you know the precise thickness of the various filters on top of the sensor, you have no way of measuring the flange distance without stripping them off to expose the sensor.
Sometimes it's best to just trust what the manufacturer says, and if the thing seems to be working properly, it probably is working properly.
Too many people think they are rocket scientists, and start trying to quantify things with what they think is precision, but end up effectively using a pointed Popsicle stick.

Mock · 11-04-2011, 01:24 PM

I used the 9.2mm measurement when making my Q-110 adapter and it was spot on.

borsuk · 11-05-2011, 01:10 AM

I used a professional optical bench so I'm almost sure that my FFD isn't 9.2mm.

Has anybody measured the thickness of ebay's adapters?

Wheatfield · 11-05-2011, 04:22 AM

Originally posted by borsuk

I used a professional optical bench so I'm almost sure that my FFD isn't 9.2mm.

Did you strip off the cover glass and various filters as well?

borsuk · 11-05-2011, 05:12 AM

Quote:

Did you strip off the cover glass and various filters as well?

I did not. It wasn't a "physical" measurement. I did not have to tuch the sensor.

Wheatfield · 11-05-2011, 03:38 PM

Originally posted by borsuk

I did not. It wasn't a "physical" measurement. I did not have to tuch the sensor.

You've got me curious now. How is the measurement done?

11-04-2011, 07:23 AM	#1
borsuk New Member Join Date: Nov 2011 Posts: 3	Flange Distance Hello Does anybody know the real flange focus distance of Pentax Q ? I've checked it myslef and my result is approx. 8.85mm instead of 9.2mm what all specifications claim. I' ve heard that adapters available on ebay focus beyond infinity. so they have to be too thin. Maybe my camera body is faulty? What are your opinion? Last edited by borsuk; 11-04-2011 at 07:35 AM.

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11-04-2011, 08:34 AM	#2
Zygonyx Pentaxian Join Date: Jun 2011 Location: Ile de France Posts: 4,033	Hello, have you included the IR filter's proper flange to sensor ?

11-04-2011, 10:50 AM	#3
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,986	As noted, unless you know the precise thickness of the various filters on top of the sensor, you have no way of measuring the flange distance without stripping them off to expose the sensor. Sometimes it's best to just trust what the manufacturer says, and if the thing seems to be working properly, it probably is working properly. Too many people think they are rocket scientists, and start trying to quantify things with what they think is precision, but end up effectively using a pointed Popsicle stick.

11-04-2011, 01:24 PM	#4
Mock Veteran Member Join Date: Feb 2009 Location: Edmonton Photos: Gallery \| Albums Posts: 314	I used the 9.2mm measurement when making my Q-110 adapter and it was spot on.

11-05-2011, 01:10 AM	#5
borsuk New Member Join Date: Nov 2011 Posts: 3 Original Poster	I used a professional optical bench so I'm almost sure that my FFD isn't 9.2mm. Has anybody measured the thickness of ebay's adapters?

11-05-2011, 04:22 AM	#6
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,986	Originally posted by borsuk I used a professional optical bench so I'm almost sure that my FFD isn't 9.2mm. Did you strip off the cover glass and various filters as well?

11-05-2011, 05:12 AM	#7
borsuk New Member Join Date: Nov 2011 Posts: 3 Original Poster	Quote: Did you strip off the cover glass and various filters as well? I did not. It wasn't a "physical" measurement. I did not have to tuch the sensor.

11-05-2011, 03:38 PM	#8
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,986	Originally posted by borsuk I did not. It wasn't a "physical" measurement. I did not have to tuch the sensor. You've got me curious now. How is the measurement done?