Getting a new telephoto lens, a few questions

[Joseph S]

Hi,
I will probably be getting a Sigma 150-500mm f/4.5-6.3 HSM lens, as sort of a birthday treat to myself, it being my birthday soon. :P
I am looking into taking pictures of birds, distant landscapes and possibly some shots of the moon.
Do you think this is the right lens for me?
I was looking at getting a teleconverter for this lens aswell, do you think this lens would go well with a TC? Also, what TCs would you recommend? I was looking at the Sigma and Kenko 2x converters, the Sony one is way too expensive for me.
I can't go over £1000 for this stuff, I have not got any more money to spend!
I am shooting with a Sony A350.
Any help would be appreciated!
Thanks.

[autofocus]

It's a pretty slow lens to start with and the converter will make it even slower by losing an additional stop or so...will that be a problem for you?

[Joseph S]

I understand it is a relatively slow lens, but I simply cannot afford a fast one with the focal length I am looking for. I also understand about the loss of stops. I don't believe this will be too much of a problem for me.

[autofocus]

Joseph, one last thing...make sure you do your research on this, or any lens for that matter. I'm not familier with this lens so I'm not qualified to pass judgement on it, but I'm sure you can find several reviews on it online. I can fully understand having to buy what you can afford, but make sure you get the best for what you can afford.

Cheers,

Vince

[Joseph S]

Yeah, I have done plenty of research. There is a lot of good reviews of this lens, and I have been amazed at most of the images take with it on Flickr.
I'm pretty sure I will be getting this lens, but I would like some more advice on the TCs, as there doesn't seem to be a whole lot of reviews on them or comparisons on the internet.
Thanks.

[autofocus]

Originally Posted by Joseph S

Yeah, I have done plenty of research. There is a lot of good reviews of this lens, and I have been amazed at most of the images take with it on Flickr.
I'm pretty sure I will be getting this lens, but I would like some more advice on the TCs, as there doesn't seem to be a whole lot of reviews on them or comparisons on the internet.
Thanks.

Sorry Joseph..can't help you with the TC's. The last one I owned was for my film / Minolta, SRT102, and that's a long time ago

[OsmosisStudios]

You might not even be able to mount a TC to that lens. If you can, it wont work well, if at all. It'll be SO slow that it won't work unless you've got insane light (f/6.3 + 2 stops = f/13). You'd be better off with a mirror lens at that point!

[Joseph S]

It's definately possible to use a 2x TC, on Sigmas website: "Compatible with Sigma APO Tele Converters" to change it to a "300-1000mm F10-12.6 MF". I have also seen people use it on Flickr with decent results.
I would be using a tripod when the TC is attached, and would usually be using it when it is nice and bright outside :P

But I also want a 2x TC for my Macro lens, so I can get 2:1 rather than just 1:1. That's a 105mm Sigma f/2.8 to convert to a 210mm f/5.6. Infact, I'd probably use it more on the macro.

[inkista]

Ok, here's the usual deal with using TCs and a slow supertele (I shoot with the Canon EF 400mm f/5.6L USM and a Kenko 1.4x tc sometimes).

2x is worse than 1.4x (some folks will even go so far as to stack two 1.4x tcs, rather than using a 2x, but I have no idea if that's a good idea, as I often hate using just the 1.4x). You get much worse image quality, and it's often not worth it, vs. cropping the photo. It can be done, but generally speaking if you're going to use a 2x tc, you probably want to be using a prime lens. But whenever you use a TC, you're going to take a sharpness hit. I far prefer shooting with the naked lens.

Secondly, whether you use a 2x or a 1.4x, you're going to lose autofocus performance, if you don't lose autofocus altogether.

The majority of dSLR bodies will stop autofocusing when the max. aperture of the lens hits f/8. That's why it's generally recommended that you only use tcs with f/4 lenses or faster for 1.4x, f/2.8 or faster for 2x.

I don't know if Sony builds in the same restrictions as Canon, but I actually cannot use a Canon TC on my 400 f/5.6L lens for this reason. I got the lower-grade Kenko because it was good quality, but also because it doesn't report at all to the body--the camera doesn't realize it's there. I don't get the multiplier information in my EXIF, as I would for the Canon, but my camera also still thinks it's shooting with an f/5.6 lens, rather than an f/8, and it gallantly continues to attempt autofocus.

It will have problems, though. Particularly with backlit birds. I've found the TC to be more of a hindrance than a help unless the bird is perched and well lit. YMMV. But if you look at photos people have been taking with TCs, more often than not the really good ones are taken with faster primes, vs. slower zooms.

[Joseph S]

Originally Posted by inkista

Ok, here's the usual deal with using TCs and a slow supertele (I shoot with the Canon EF 400mm f/5.6L USM and a Kenko 1.4x tc sometimes).

2x is worse than 1.4x (some folks will even go so far as to stack two 1.4x tcs, rather than using a 2x, but I have no idea if that's a good idea, as I often hate using just the 1.4x). You get much worse image quality, and it's often not worth it, vs. cropping the photo. It can be done, but generally speaking if you're going to use a 2x tc, you probably want to be using a prime lens. But whenever you use a TC, you're going to take a sharpness hit. I far prefer shooting with the naked lens.

Secondly, whether you use a 2x or a 1.4x, you're going to lose autofocus performance, if you don't lose autofocus altogether.

The majority of dSLR bodies will stop autofocusing when the max. aperture of the lens hits f/8. That's why it's generally recommended that you only use tcs with f/4 lenses or faster for 1.4x, f/2.8 or faster for 2x.

I don't know if Sony builds in the same restrictions as Canon, but I actually cannot use a Canon TC on my 400 f/5.6L lens for this reason. I got the lower-grade Kenko because it was good quality, but also because it doesn't report at all to the body--the camera doesn't realize it's there. I don't get the multiplier information in my EXIF, as I would for the Canon, but my camera also still thinks it's shooting with an f/5.6 lens, rather than an f/8, and it gallantly continues to attempt autofocus.

It will have problems, though. Particularly with backlit birds. I've found the TC to be more of a hindrance than a help unless the bird is perched and well lit. YMMV. But if you look at photos people have been taking with TCs, more often than not the really good ones are taken with faster primes, vs. slower zooms.

Here are a few very nice shots taken with this lens with the 2x TC:
Sigma 150-500mm OS HSM + TC 2X on Flickr - Photo Sharing!
Merops apiaster on Flickr - Photo Sharing!
J. A. M. S. on Flickr - Photo Sharing!
The Moon - Cropped on Flickr - Photo Sharing!
Philippine Hawk-Owl (Ninox philippensis philippensis) Sigma 150-500 APO DG OS on Flickr - Photo Sharing!
100% crop of above image: Philippine Hawk-Owl (Ninox philippensis philippensis) Sigma 150-500 APO DG OS on Flickr - Photo Sharing!
The last of my pelican shots (for now) on Flickr - Photo Sharing!

There is a definite loss of sharpness, but not as much of a loss as you would get through cropping.
I know I will lose AF, it will be altogether, or at least I am expecting to lose it altogether.

As I have already stated, I think this would be useful for my Macro lens as well though.


Can I have any recommendations as to which TCs are the best/best value for money?