Lens Question

[Kawidude]

During certain parts of the year, I do quite a few group shots for our local high schools. It basically involves lining everyone up in a small amphitheater, which most of the time is not a problem as far as fitting everyone in the frame. Our "do it all lens" is a Tamron 28mm-105mm f/2.8 being used on a Fuji Finepix S2 Pro.

When I'm shooting in the amphitheater I literally have my back against a wall in order to get as much of the sides in as possible. Some shots have a lot of kids and squishing them in gets to be a hassle.

I am looking at a used Tamron 19mm-35mm lens to use for these type of situations. My question is that I can't figure out exactly how much more I'll be able to get in frame with a 19mm versus the 28mm that we already have. I just want to get an idea of how much more room I'll be getting in the frame before I spend the money on the lens. I will probably be using this lens about a dozen times a year, so that's why we're looking at used lenses right now.

I am typically about 12-15 feet away from the front row of the amphitheater when I shoot. Is there any equation or something that will tell me how much more room I'm buying with the 19mm? Thanks in advance for any guidance you can provide.

This is one of the more recent shots I've taken there. It would work fine if they were getting 5 x 7 prints, but the prints will actually be 8 x 10's, so I'm probably going to have to clone in some additional background to fit everyone in properly. Again, this is with my back against the wall and a focal length of 28mm.

 

[Rich Rohrich]

Kawidude - I think this is a situation where that 10-20mm Sigma we talked about or the Tokina 12 - 24 mm f/4 would work incredibly well.

Look up the specs for maximum angle of the lens and with a little geometry you should be able to figure out the display differences between your existing lens and the other ones out there.

 

[Kawidude]

Thanks Rich. I actually recommended the Sigma 10-20mm to the "boss man," but since it's going to be used about a dozen times a year I get the feeling he doesn't want to drop that much coin.

I'll see if I can find the maximum angle of the lens. Then I'll see if I can find someone that remembers what geometry is.

 

[Okiewan]

Here's a quick example I just shot....
inner shot is at 28mm(+/- 1mm), outter at 18mm. The inner shot had to be reduced by 35% to "fit", so, that's roughly how much more scene you get.
Careful going too wide with group shots.... barrel distortion.

 

[Kawidude]

Okie, that is HUGE for me! Thank you. I took Rich's adivce and found out the maximum angles for the lens I have and the one I'm looking at. I called another buddy and had him work the geometry. The numbers made sense to me, but it really helps being able to see the difference. I wanted to go and do test shots with the new lens, but the guy isn't available until late at night. Thanks again! I'm showing this to the boss-man.