Tables of Lenses

[Dansndais]

Thanks so much for this information.
This is a great forum!!!!!!!!!!!!!!!!!!!

[tomtam]

very good job!

[20droger]

You are welcome.

Be sure to come back every couple of months, as this is a "work in progress."

[20droger]

Just update the main lens tables today, 1 September 2007.

[bomboman]

Thanks very big : )

[20droger]

Just updated the tables again, mid-April 2008.

[xn2b8r]

Usually I learn plenty from reading the forums, but I'm over my head this time. How can I use the tables or a spreadsheet (sorry, my only calculator does basic math only) to figure out the width and height (in feet) of the frame at a certain distance, using a certain focal length and a 1.6 sensor (40D)?

Specifically, if I am shooting a baseball game and I am limited to a specific distance from home plate, what formula can I use to determine what lens I should rent to capture a 7-foot-high frame with the camera positioned in portrait (vertical) orientation? I'd like to use as long a focal length as possible to shorten the DOF because of the distracting background.

Thanks for any help anyone can offer.

[Vermin87]

A 100-400 L would probably be plenty. A 70-200 could probably do it also.

[gkuenning]

The easy way to figure this out is to use the laws of proportions.

Set up your camera with any lens you choose (except fisheyes), and with a known focal length. Shoot a tape measure stretched across the frame. Measure the distance from the tape measure to the nodal point of your lens. (Don't know the nodal point? Guess it at about 1/3 of the way from the back of the camera to the front of the lens; this isn't a critical measurement unless it's a really short lens.)

Now you know how wide your frame is at a given focal length and a given distance. From here there are two simple rules:

1. The frame coverage increases in direct proportion to the camera-to-subject distance. In other words, if you double the distance, the frame coverage doubles. Cut the distance to 60% of the original, your frame coverage drops to 60% of what you measured.

2. The frame coverage decreases in inverse proportion to the focal length. If you double the focal length, your frame gets half as big.

To make the calculations easy, I'd measure at a convenient distance, say 10 feet, and with a convenient focal length, such as 50mm. But with a little algebra and a calculator, it doesn't really matter.

From the above discussion, we have:

new f.o.v = (old f.o.v) * (old fl / new fl) * (new dist / old dist)

where f.o.v is your field of view in any units you choose, fl is a focal length, dist is the distance to subject, old represents what you measured, and new represents whatever you'd like to photograph (i.e., your baseball game). Rearranging this to get the focal length needed at the park, we get:

new fl = (old f.o.v) / (new f.o.v) * (old fl) * (new dist / old dist)

I just did a quick (and inaccurate) test with my 30D and 17-55, and came up with an f.o.v. of 12 inches (horizontally) at a distance of about 27 inches. Inches aren't very convenient, but we can use the rule of proportions to conclude that the f.o.v. will also be 12 feet at a distance of 27 feet. Plugging that into my formula, using your 7-foot figure, and assuming 100 feet to home plate, we get:

new fl = 12 / 7 * 55 * 100 / 27 = 349mm

So at 100 feet, a 100-400L would give you the frame size you need. For the outfield, you'd probably want a 500 and a monopod, or a teleconverter.

The other thing to consider, of course, is whether the park will give you trouble about using such a big lens. In major-league parks, they might object because the lens will block the view for other people, or even create a safety hazard by blocking the aisles. If you're going to a pro game, even minor-league, I'd suggest you call ahead (anonymously) and ask about the rules. There's been some discussion of this point in the last few weeks of the "Post the most ridiculous comments" thread.

[xn2b8r]

Very helpful! Thanks, Geoff

- Jeff

[aero.nz]

Wow thanks, great resource

[ThomGascoigne]

Thanks that was really helpful, I'm wondering if you've made a version that is listed as by manufacturer and then from smallest to biggest focal length, Ie with Canon starting with the 14mm and ending with the 800mm

[gilariver]

When I try to download this pdf file, an HTM file is downloaded. What gives?

[20droger]

Originally Posted by gilariver

When I try to download this pdf file, an HTM file is downloaded. What gives?

Very strange, since I never made an HTML file of these tables. PM me your email address, and I will send a zip of the PDF files directly to you.

[sajannarain]

I have gone through all the valuable information and would also request you to kindly send me the pdf file by email at sajan_narain@hotmail.com .
Thanks a lot in advance.