Comments on: How to Calibrate Your Zoom Lens To Capture What Your Eyes See

By: Fernando Tavares

Fernando Tavares — Wed, 12 Aug 2009 12:04:47 +0000

I’m late but this website is huge.
Ok Gary, your article is perfect. To match the two views, we have to do it like you said. There is no other way.
I’m a photographer but also a tv cameraman. Tv Lenses have big zoom ratios, 14x, 16x, 20. When i want to put on screen the same “perspective” relation of size distance, etc, of objects, I use this technic. People have to understand, that there are two different things we are talking about here. One is the relation between objects ( the notion we get of the distance between two trees distant apart 50 meters in our line of view, when we use a 50mm or a 300 mm, is huge – mostly the concept of perspective for photography). The other thing is how wide we can see without moving our eyes. I, have an angle of peripheral view, with detail, of about 120º horizontal. With no detail but still can see you move, 175º. Used to be 190 on my 20’s I’m 50 now). Meaning, I can see more wide than my canon 15mmf2.8 fish eye. But if i take picture with it, the relation of things in distance is diferent from how I see it.( strait line in front, not the optical distortion).
This means, that to have the same notion of reality of my eyes, i use the two eyes method, to try to see as wide as my vision, i use a wide angle.

Just one thing more, for those who didn’t understood it, this is not a technic to manually focus a lens.
For that, you can do two things, first, just do it, manually. Second, also with auto focus of, press halfway, and rotate the focus ring at the same time. When your active focus square sensor( the one that illuminates red) lights, the object is in focus. This is a technic widely used by pros. And it is explaned in some user manuals of some cameras.

BR
Fernando

By: Silverhalide

Silverhalide — Sun, 22 Mar 2009 04:10:00 +0000

Without getting into whether it’s useful to match what you see in the viewfinder with what you see with the naked eye, I thought I’d mention that dpreview has an interesting blog entry on normal lenses which touches on some of the issues discussed here such as whether normal lenses match viewing angle, and how viewing distance is related.

http://blog.dpreview.com/editorial/2009/03/what-is-a-standard-lens.html

By: iamunique127

iamunique127 — Tue, 17 Mar 2009 11:49:51 +0000

Mr. Millwater
I have often thought about this and wasn’t aware of this quick and easy way to find the “normal” view. I have just used the zoom calibration of around 35mm. This works with any zoom in the “normal” range and with any camera. Thanks for the informative post.

By: Author

Author — Fri, 13 Mar 2009 03:43:17 +0000

Tonya, it seems as though were on the same page. Someone finally got it… Like you, I’ve been using this routine for years shooting motor sports, cycling, and recently, extreme sports. Perhaps others will catch on and find this procedure useful.

By: tonya

tonya — Thu, 12 Mar 2009 16:00:13 +0000

Don’t know if this is the same thing, but this is also how I shoot fast moving sports (volleyball, hockey, soccer). I keep both eyes open, with my field of view calibrated to what I actually see (as described above) and then I can follow the action as its happening and I know before something enters the frame that it is about to. Much less panning around (”follow the ball”) this way. My “outside” eye sees everything happening outside the frame and as it transitions into the frame my “inside” eye (the TTL eye, if you will) picks it up. As the author describes above: “At this point, you should be able to remove and replace your camera from your eye with no apparent change in your target.” I know I have it exaclty right when I no longer feel like I am looking through a camera but that I am just watching the game. It kinda feels like being “in the zone” and I get the best photos in those moments.

By: Fredshome

Fredshome — Thu, 12 Mar 2009 15:11:41 +0000

My zoom lens is a 200-500 you insensitive clod !

Apart from that, that’s one way to set the dioptric setting in the visor.

OTOH, I don’t really see what the point is in geting the camera to see what the eye sees. I might be atypical but I can’t recall ever wanting to use any one of my cameras that way. I use them to capture something specific.

Oh, and it seems to me that with APS sensors, the “magic number” is closer to 35-40mm than to 50.

By: Author

Author — Tue, 10 Mar 2009 22:20:12 +0000

Actually I’m not surprised that the responses to this article are way too analytical. The premise of the article was to give the user a way to capture an image close to what they are seeing, before they take their shot. Indeed, when we concentrate on something we humans tend to have tunnel vision. If that were to equate to a focal length, I would have to agree on the 70mm range. If we were to relax our vision our fov or aov would be much greater, probably around the “normal” range of around 43.3mm. However, the only way to know for sure would be to take an image after the calibration, enlarge it to life size, then compare that image side-by-side with the subject. But for those it may have helped for whatever reason, your welcome. That’s the whole point of this website…to share anything that may help others in their photographic endeavors. If optical physics is what your after, then there are websites for that too.

By: Lirou

Lirou — Tue, 10 Mar 2009 03:06:03 +0000

That doesn’t work at all. I got 70mm as normal on a 18-135mm lens and a DX body. And I know by experience that normal is around 35mm on a DX.

This may work if the viewfinder has no magnification. But that is not the case for most cameras.

By: fbo

fbo — Mon, 09 Mar 2009 20:45:06 +0000

I think that perspective and field of view are 2 different things. The sensor size will affect the field of view, with the crop factor. The perspective is left intact, as far as I see it. Therefore, I would suppose that everybody should be getting results around 50mm regardless of sensor size.
I just tried it with my 40D and it came around 55mm.

By: C

Sun, 08 Mar 2009 17:30:17 +0000

I also got 50mm on a 40D as “normal,” which translates to 80mm.