Sigma 170-500mm APO DG & TCON?? (1 Viewer)

[Quacker]

Does anyone know, or has anyone tried, the Sigma 170-500 with a TCON and had success?

When I say success, I know they can and will work, but do they work with full AF or at such focal lengths is MF a price to pay for such a (relatively) slow lens?

Any comments appreciated

Steve

 

[hollis_f]

Does anyone know, or has anyone tried, the Sigma 170-500 with a TCON and had success?

When I say success, I know they can and will work, but do they work with full AF or at such focal lengths is MF a price to pay for such a (relatively) slow lens?

Any comments appreciated

Steve

It all depends on your camera. However, most of them give up trying to autofocus at anything more than f5.6. As that's where the 170-500 starts and adding a TC will reduce the effective aperture you're going to be using something around f8 to f11 (for 1.4x and 2x TCs, respectively). That means no AF.

It may be possible to fool the camera into thinking there's no TC present. But that'd probably make the AF so slow and unreliable that you'd be better off with MF anyway.

 

[baillieswells]

Does anyone know, or has anyone tried, the Sigma 170-500 with a TCON and had success?

When I say success, I know they can and will work, but do they work with full AF or at such focal lengths is MF a price to pay for such a (relatively) slow lens?

Any comments appreciated

Steve

According to the Sigma literature, their teleconverters wil not work with the Sigma 170-500mm DG lens. I have tried the Canon 1.4 extender and it will not fit because of the protruding front lens which has a rubber shield around it. (The Sigma teleconverters also have a protruding front element). I believe there are a couple of manufacturers make ones which don't have this protruding front element, Tamron is one of them. They might fit, though whether they would work in the AF mode I doubt.

 

[kennygee]

I think the Kenko TC's also fit.

 

[Quacker]

Sorry folks, I should have added with the 350D camera. I got a reply from Sigma advising the same as Baillieswells that their own TCONS do not work - but they did advise to check locally e.g. Jessops as it is possible others might work, or as suggested, work in a fashion.

It was just one of them questions that I needed to ask when considering future purchases.

So to sum up some will work, but none will give full AF - seems fair enough.

Steve

 

[baillieswells]

Sorry folks, I should have added with the 350D camera. I got a reply from Sigma advising the same as Baillieswells that their own TCONS do not work - but they did advise to check locally e.g. Jessops as it is possible others might work, or as suggested, work in a fashion.

It was just one of them questions that I needed to ask when considering future purchases.

So to sum up some will work, but none will give full AF - seems fair enough.

Steve

As I understanf it, the Tamron and the Kenko are the same with different names. According to their literature the latest Kenko 1.4 Pro 300 should only be used with lenses of f2.8 and larger, and that using a smaller f number lens, the quality may be impaired. They also produce a simpler and cheaper model, which may work with an f5 or worse. Again according to the literature the Pro 300 series are said to be the equal of the Canon 1.4 Mark II which is what I use with my Canon f4 70-200mm L lens. I also use a Canon 350D, and with the Sigma 170-500mm with the multiplier factor of 1.6 this represents a maximum of 800mm. I have also only received it this week, and I want to make absolutely sure I can master it before wanting to increase the maximum focal length to 1120mm with a 1.4 converter.

 

[SMC2002]

Quacker,
Do you know if the 170-500mm actually has a max aperture of F5.6 @ full tele? The reason I ask is that my 50-500mm is also supposed to be F5.6 @ full tele, but is in actuality F6.3 (which Sigma fully acknowledges). It lies to the camera so that AF capability is maintained. Sort of like the cheap Tamron 1.4X teleconverter. It passes aperture info straight through to the camera.

This TC will work with the Bigma (and most likely for your 170-500mm) for sitting targets, but does not work well at all for in flight shots. My opinion is that the slow AF/hunting issue is linked to the F6.3 max aperture. I use this same TC on my 70-200mm F2.8 and my 400mm F5.6L and it works fantastic for in flight shots. Yes, the AF slows somewhat, but still very useable.

So since no one has confirmed that TCs work with this lens, I'd try to find out if tele max aperture is actually F6.3. If it is, I wouldn't invest in a high quality TC. The inexpensive Tamron is around $100usd, so it might be worth a shot

Steve

 

[Quacker]

In all truth, I cannot say as I'm awaiting delivery of mine. Perhaps it can be thrown over to someone who can answer either way?

 

[psilo]

Hi Steve
I have the kenco pro 1.4 converter and it does work with the 170-500mm lens on the 350d. However you do need to use manual focus and you do need a very bright day for it to be a fast enough combination. I have used this tc a few times in the field and have never been happy with the results as the focus just isnt sharp enough for my liking, but then I am no expert when it comes to thier proper use.
btw the telemax on the 500mm range is definatly 6.3.

 

[SMC2002]

Hi Steve
I have the kenco pro 1.4 converter and it does work with the 170-500mm lens on the 350d. However you do need to use manual focus and you do need a very bright day for it to be a fast enough combination. I have used this tc a few times in the field and have never been happy with the results as the focus just isnt sharp enough for my liking, but then I am no expert when it comes to thier proper use.
btw the telemax on the 500mm range is definatly 6.3.

Psilo,
Agreed. I have the same issue using a TC with the Bigma. Slow AF, the AF gets lost easily and the focus just doesn't seem to be as sharp as when shooting with just the lens alone. Not having the eyesight I used to, manual focusing is pretty much out of the question for me :-(

Steve

 

[psilo]

Yes steve. I have a problem with pain in my hands often which makes mf very difficult for me too. I have decided not to bother with a tc for now and just use my 500mm. What I lose in distance just isnt made up for in quallity of focus. I use to use the same tc on my 300mm and only ever got sharp focus against bright skies.

 

[hollis_f]

Last weekend I tried using my Kenko 1.4 TC on my 70-300mm. The autofocus was dire. But I found I could helpit along by using the manual focus ring to get close, then the AF stepped in and nailed it (sometimes). Of course, this will only work on a lens with full-time manual focussing (which is rapidly becoming a must-have for me).

 

[Nick-on]

Way back in the dim and distant past I used a Sigma 170-500 with a Jessops 2x TC on my Nikon F50. AF wasn't too bad providing you had good light and reasonable contrast.

Nick

 

[Quacker]

Light is the word!

My camera hasn't arrived yet and already Im discovering the importance of that element!

Maybe we should forget make, model lens, zoom or prime and list light at the top - even above technique 3

TCon can wait then.

Thanks again for all input & debate