LENSES FOR : Indoor Swimming Competitions [HELP!]

[shiroutsuki]

OK so I use a Nikon D3000 with the standard 18-55mm lenses & was thinking of purchasing a new pair of lenses specifically for indoor swimming competitions, but I'm not sure which one I should get. Problem is, I'm on a tight budget, being a student and all, so I would really appreciate any suggestions or feedback on the lenses I had taken a look at which are listed in the following: Sigma 70-300mm DG MACRO Telephoto Lens for Nikon & Nikon AF-S VR Zoom-Nikkor 70-300mm Zoom Lens & Nikon 55-200mm Nikkor Lens (AF-S DX).

P.S. Another thing I was wondering about were "teleconverters" or "extenders" and have heard that at 2X they degrade the image or is that true for 1.4X - 1.7X as well? Too bad it seems that they're not compatible with my current lenses though....

Thank you! (:

[inkista]

Originally Posted by shiroutsuki

... I had taken a look at which are listed in the following: Sigma 70-300mm DG MACRO Telephoto Lens for Nikon & Nikon AF-S VR Zoom-Nikkor 70-300mm Zoom Lens & Nikon 55-200mm Nikkor Lens (AF-S DX).

Ok. Quick lesson. Take the time to go read this article on maximum aperture. If your pool is outside, those lenses might work for you, but they're going to be severely limited by max. aperture for shooting inside at the shutter speeds you're going to want to freeze the action.

If you want a zoom, chances are there's no way around it, you're going to pay the big bucks or learn to light a swimming pool. Neither of which is a particularly easy row to hoe. What you really want in this situation is a 70-200 f/2.8 of some kind. Tamron & Sigma make $700 versions, but that's about the cheapest you're going to find.

Your only other option is to go with a fast prime, which, while it may free you from the tyranny of "not enough light" is likely to screw with you framing-wise.

P.S. Another thing I was wondering about were "teleconverters" or "extenders" and have heard that at 2X they degrade the image or is that true for 1.4X - 1.7X as well? Too bad it seems that they're not compatible with my current lenses though....

All tcs degrade image quality, but yes, the 1.4x ones don't do it as badly as the 2x ones will.

The main problem (and this goes back to the compatibility thing) is that tcs also decrease your maximum aperture. The math works like this.

aperture diameter = focal length/f-number

So, a 200mm lens, set at f/2.8 has an aperture diameter of:

200/2.8 = 71.4mm.

That aperture doesn't change when you add a tc to the lens. But the focal length does. So if you added a 2x tc to the 200mm lens, you'd get:

400mm/f-number = 71.4mm; f-number = 400mm/71.4mm = 5.6.

You've lost two stops off your maximum aperture. A 1.4x tc loses you a single stop. So you're going to be even MORE squeezed for light than you were without the converter.

Worse than that, if you use one in a lens that's already at f/5.6, you're going to lose autofocus completely. Non-pro dSLRs tend to stop autofocusing when the max. aperture of the lens hits f/8.

Obviously, requiring more light and not having autofocus isn't going to make for an ideal situation while shooting sports. Indoor sports is one of the most demanding subjects when it comes to lenses, because you need reach and speed. Either one tends to be expensive, but in combination, it can get astronomical.

[shiroutsuki]

@inkista :

Woah, awesome! (: Seriously, this was VERY helpful and I learned a lot, especially about max.apt. & TCS! I'm definitely going to go for either the SIGMA or the Tamron 70-200mm f2.8 (:

Thanks a million! (:

[inkista]

Sorry it was all bad news. But happy to have helped!

[shiroutsuki]

LOL it wasn't bad news at all! >: D I'm really grateful for your help! :3 Thanks again! ;D