Teleconvertor Question

[birdeast]

I have been reading everything that I can find on teleconvertors - The pros and cons. Seems like some people have good experiences while others do not. I have seen some really good photos with TC's (even stacked TC's) here on this forum. Is the difference down to quality control or is technique the issue?

I am thinking about using a TC with my Sigma 100-300mm f4 lens. I am using this lens exclusively with a Manfrotto tripod / head and an infrared remote shutter release. If I were to try a Sigma 2x EX teleconvertor under these conditions while shooting primarily toward the sky (birds in top of tree) or toward water (wading birds), could I expect decent to better than decent photos at say f8 to f11? Would I be better off being conservative and trying the Sigma 1.4x EX TC? The pricing is pretty close and I am scratching my head trying to decide which TC to try.

Appreciate your input

Scott

[compa]

With a teleconverter the issue is that you lose light. It is harder to focus and exposure times are longer (assuming aperture setting is the same). Also since the lens is effectively longer, your technique becomes critical. All of this frequently adds up to less than sharp images.

It naturally follows that a 2x teleconverter is harder to use successfully than a 1.4x would be. With the 2x you may find it necessary to use additional tricks such as mirror-lockup that may not be needed with a 1.4x. Personally I'd stick with the 1.4x for starters.

I have a few things about teleconverters on my website:

Kenko 3x teleconverter
http://www.jbs-blog.com/?p=60
http://www.jbs-blog.com/?p=72


Canon 1.4x teleconverter
http://www.jbs-blog.com/?p=66

Good luck!

[pxl8]

Hi Scott,

I would be tempted to say the 2X is better on the basis that you can always zoom out if need be - better to reach too far than not far enough!

If possible ask your camera shop if you can take a couple of shots with the TC's hooked up to your 100-300mm so you can look at the results at home and judge from there.

[formula4speed]

Generally speaking I wouldn't put a 2x converter on any zoom lens. Aside from losing 2 stops of light it also degrades the image quality. On your lens this will also mean lack of autofocus unless you have a 1 series body. The 1.4 converter will make you lose 1 stop of light, you'll maintain autofocus and there will be minimal degredation of quality.

[nikovich]

I have so far had really good results - the best piece of advice I'd give is a steady hand or a tripod !

[jimtfoto]

Generally speaking I wouldn't put a 2x converter on any zoom lens. Aside from losing 2 stops of light it also degrades the image quality. On your lens this will also mean lack of autofocus unless you have a 1 series body. The 1.4 converter will make you lose 1 stop of light, you'll maintain autofocus and there will be minimal degredation of quality.
I have been using a Sigma 2X on my 50-500 for the past couple of months. Takes a bit getting used to manual focus again. I have found, however, that given the right light conditions there is little degradation in image quality.
With my 1.4 TC on the same lens, I find that autofocus still hunts. You will need absolutely brilliant light conditions to maintain autofocus. I don't use the 1.4 too much ... if I have to manual focus anyway, I'd rather have the extra reach.
cheers,
jim

[robski]

I think your find that the satisfaction factor is dependent on the quaility of the lens your attaching the TC to. I have a Canon 300mm L prime lens with Canon 1.4 TC and I am pleased with the results, only a slight degradation in image quaility. When I was doing my research into the subject the following 2 factors on image quaility became apparent.

1, more people were happier with a TC attached to a prime lens than a zoom.

2, more people were happier with a x1.4 TC than a x2 TC.

I found a site that demonstrated that photoshop resampling gave slightly better results than a Canon x2 TC on a Canon L prime lens.

Having said all of this I also read that the Sigma 100-300 f4 and Sigma TC appears to be designed to match each other and give quite good results. Probably why you see them sold as a pair.

Your best bet is as mentioned before is to try both the 1.4 and 2 before you buy.

Robert

[Lindsay Cargill]

I have started using a Kenko Pro300 1.4x tele on my Tamron 200-500 D70S setup. Although it is early days and I am still getting used to it I would say the converter softens the image somewhat especially in poor light - which can be often up here in Aberdeen when using a 500mm ! However, I have had some resonable results and the extra reach is handy for closing in on small finches - my passion.

Linz