Generic Lenses

[Poider]

I am looking for a lens to share between my wife and I for bird watching, I have considered sigma or tamron 150 to 500mm, I was warned away from the generic lenses because the maximum aperture at the long end is f/6.3, which is not real good fro low light, but couldn't we just compensate with a slightly longer shutter speed, after all for shots that far away we are going to be using a tripod any way and the difference between the 6.3 and 5.6 is not that great anyway is it, or am I being ignorant?
Peter

[Hero]

Slower shutterspeeds aren't going to help when photographing birds....Unless they sit perfectly still. A tripod will help you overcome your own movement, but not the movement of birds you try to capture.

[Andrew1]

There's always the tradeoff. A good lens with some trade-offs or a great lens with an empty bank account.

[Mark von Kanel]

I have the sigma 50/500 and its fine for shooting birds in most conditions, the auto focus works fine at 6.3 just push your iso up to help if you need to the D7k is fine up to 6400 in most conditions, cant you hire one and have a play?

[Poider]

I don't know of any hire places in south australia
Peter

[Glenn NK]

This would be my suggestion - push the ISO. Better to have a bit of noise than a completely blurred image.

Glenn

[Geoff F]

Peter, while I find the Sigma 150-500 to be an excellent lens in many respects there are a few potential drawbacks for some uses.

Personally, I prefer to work at F8 as the max open position whenever possible. Also the auto focus is a bit on the slow side. Fine for sitting birds but sometimes a bit too slow for the quick fliers. OS stabilisation is surprisingly effective even at 500 mm providing you have a reasonable shutter speed.

But what alternatives are available at a 'sensible price'?

Firstly what camera are you using? When I was considering a larger lens, and using Canon, I also considered the 100-400 and a 400 mm prime.

But I thought that as I would probably be wanting 500 mm a lot of the time, I might as well get a 500 mm lens to start with. The 400 mm will take a 1.4x without any problems but it has a rather long minimum focusing distance of around 11 ft which can be a bit limiting for other uses. Other makes may be a little better in this respect.

A 500 mm prime is one of the preferred lenses by serious bird photographers; but, whatever make, they have a considerable price tag and limitations for other uses. And, unless you spend a bit extra, for a faster lens, a 400 mm plus converter probably won't be any different to a F6.3 lens anyway.

[Poider]

Thank you to all of you, I am using a Nikon D7000, and my wife a NikonD3100.
Peter