XH A1 Field of View distances? at DVinfo.net

Chris Soucy · November 24th, 2010, 07:41 PM

Does anyone know if there have been published figures for actual horizontal FOV distances @ say, 100 metres, for the minimum and maximum lens focal lengths of the A1 lens?

In case I lost anyone there, I'm trying to find the actual edge to edge distances in frame at a certain distance from the camera at both max wide and max zoom in.

In case anyone put's their hand up as being able to work it out, try at exactly 17.18 metres from the camera.

Why 17.18 metres do I hear someone asking?

Ah, well, at 17.18 metres from the camera, 1 minute of arc equals 5 mm (if Einstein here has done his sums correctly, that is).

And this is important, how, exactly?

I knew you'd ask that.

It gives me a convenient unit of measurement to track camera support rotation under load, which can them be mapped onto 1920, being the horizontal pixel count of an HD sensor and thus allows me to say that this system, under that load, will produce a pixel shift of "?" in the x axis and "&" in the y axis.

Simple.

CS

Don Palomaki · November 24th, 2010, 08:09 PM

Well, The Century Optics web site (their specs on the 0.6 Wide adapter) lists the horizontal field of view to range from 58° to 3.2° for the standard lens. That translates to about 1.1x the distance at the wide end, and 0.056x the distance at the telephoto end. At 100M that would be about 110M wide and 5.6M tele.

A quick rough check with my XH1A at 25' indicates this is about right, without compensating for and CVF overscan. Would not be difficult to do a more precise test.

Chris Soucy · November 24th, 2010, 08:22 PM

Thanks. (Forgive the typos, it's a fact of life at the moment, I'm hoping it will improve:)

For some reason I thought this was just gonna run and run.

Boy, have you saved me some time.

I love this place.

CS

November 24th, 2010, 07:41 PM	#1
Chris Soucy Inner Circle Join Date: Feb 2007 Location: Fairfield, Dunedin, New Zealand Posts: 3,691 Images: 18	XH A1 Field of View distances? Does anyone know if there have been published figures for actual horizontal FOV distances @ say, 100 metres, for the minimum and maximum lens focal lengths of the A1 lens? In case I lost anyone there, I'm trying to find the actual edge to edge distances in frame at a certain distance from the camera at both max wide and max zoom in. In case anyone put's their hand up as being able to work it out, try at exactly 17.18 metres from the camera. Why 17.18 metres do I hear someone asking? Ah, well, at 17.18 metres from the camera, 1 minute of arc equals 5 mm (if Einstein here has done his sums correctly, that is). And this is important, how, exactly? I knew you'd ask that. It gives me a convenient unit of measurement to track camera support rotation under load, which can them be mapped onto 1920, being the horizontal pixel count of an HD sensor and thus allows me to say that this system, under that load, will produce a pixel shift of "?" in the x axis and "&" in the y axis. Simple. CS

November 24th, 2010, 08:09 PM	#2
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,488	Well, The Century Optics web site (their specs on the 0.6 Wide adapter) lists the horizontal field of view to range from 58° to 3.2° for the standard lens. That translates to about 1.1x the distance at the wide end, and 0.056x the distance at the telephoto end. At 100M that would be about 110M wide and 5.6M tele. A quick rough check with my XH1A at 25' indicates this is about right, without compensating for and CVF overscan. Would not be difficult to do a more precise test. __________________ dpalomaki@dspalomaki.com

November 24th, 2010, 08:22 PM	#3
Chris Soucy Inner Circle Join Date: Feb 2007 Location: Fairfield, Dunedin, New Zealand Posts: 3,691 Images: 18	Dom, you're the man............. Thanks. (Forgive the typos, it's a fact of life at the moment, I'm hoping it will improve:) For some reason I thought this was just gonna run and run. Boy, have you saved me some time. I love this place. CS Last edited by Chris Soucy; November 24th, 2010 at 10:52 PM.