2x converter on a Sigma 50-500 OS lens?

[hee]

I don't know if this is a dumb question but is contemplating getting a 2x converter for a Sigma 50-500 lens absurd or are there people out there using such a combo and getting reasonable results for wildlife photography in good light (camera is Canon 7D).
Is there any practical drawback to an older Sigma EX converter vs the newer DG model ?

[I @ M]

The only dumb question is the one question that you never ask.

If you mount a 2x converter on your bigma you will almost certainly loose auto focus at both ends of the focal range ( and everywhere in between ) as most camera bodies ( not too sure about the 7d ) will only perform auto focus at a maximum of F/5.6 with any degree of accuracy.
If you can accurately manually focus through the viewfinder on moving wild life at 500mm and expect to get clear images at F/11 + then you may be happy using one. The other down side is that the quality of the image may well suffer at such reduced apertures with the added glass introduced via the converter.

Yes, the older converters ( we have one ) are not as optically good as the newer ones, there still do give reasonable quality though when used appropriately.

There is no such thing as a free cheap lunch when it comes to converters and variable aperture "slow" lenses.

[fess67]

I don't beleive you will get your moneys worth. As has been said, you lose AF, you need a lot of light, you lose image quality, you will almost certainly need to use a tripod, reducing your mobility. If you happen to get a shot at extreme range I don't think you will be happy with the results given the above factors.

What wildlife are you interested in shooting? Is it in a safe area - i.e. no predators around to put you in danger?

Perhaps a small hide or some camoflage clothing would be the way to go. Set the hide up in an area you know the wildlife to be active and give them a little while to get used to it - before you know it they will be close enough for you to use a macro lens :P

[hee]

Thanks guys, I'll scrap the idea of the converter

[Mark L]

Where are you AM?

[Wayne]

It will be so dark through that viewfinder at 500mm you will need ISO of the 1DX to get a usable shutter speed.

[ameerat42]

I can verify some of the foregoing.
Yes, it works with the Σ2X converter.
Yes, it is sharp with it too.
Yes, there's NO AF anywhere with the 2X on, BUT there IS OS and it IS EFFective.
Yes, the OS is really good for this lens even at 500/1000mm, allowing good exposures,
down to 1/100sec hand held (unless you've really been on the turps beforehand).

Sorry Wayne and Fess, but it's not so dark in the viewfinder at even 1000mm. It meters with the lens wide open
with the 2X on (showing about f/13). At this f/stop you still get pretty sharp shots.

What else?
Oh, the zoom will creep if the lens is held steeply away from horizontal... Er-r-r...
It has got a zoom lock, but only for the closed zoom end, more for transportation.
And... Oh, it has two OS positions: half-shutter press and continuous.

I don't think you can get the (?old) EX converter any more, but the DG is designed for full-frame (as is the lens).

Worst of all (not) it appears to be sharp everywhere in the zoom range, with and w/o the 2X.

Well, I was going to say there are worse things than getting a (Σ)2X for this lens. You might have found one.
Call it NOT extending the potential of what you must know to be an already good lens. Now, just don't slip on a banana skin as well.
Am.

[Mark L]

I can verify some of the foregoing.
Yes, it works with the Σ2X converter.
Yes, it is sharp with it too.
Yes, there's NO AF anywhere with the 2X on, BUT there IS OS and it IS EFFective.
Yes, the OS is really good for this lens even at 500/1000mm, allowing good exposures,
down to 1/100sec hand held (unless you've really been on the turps beforehand).

Sorry Wayne and Fess, but it's not so dark in the viewfinder at even 1000mm. It meters with the lens wide open
with the 2X on (showing about f/13). At this f/stop you still get pretty sharp shots.

FWIW late last week I saw this to be true.
Seems Am mostly uses manual focus anyway, and this is possibly your biggest consideration here hee.

[fess67]

FWIW I have had very poor results with this lens without a converter. I think the performance is likely dependent on ability so unless you are pretty good you will be upset with the quality you get. i.e. - the images will not live up to the desire

[Wayne]

Metering at f/13 is going to fine for the bright sun of the day, but how does it perform at about 6am/8pm with the 2xTC without a tripod?

[ameerat42]

FWIW I have had very poor results with this lens without a converter. I think the performance is likely dependent on ability so unless you are pretty good you will be upset with the quality you get. i.e. - the images will not live up to the desire

Fess. I have seen your work and I certainly acknowledge that you may have something to say. I would be interested in an expansion of "very poor results" however, as it is also interesting. However, "hee" has already got this lens, hasn't he? It is more the 2X he was talking about. And it would be interesting to determine how "hee's" experience matches up with your admonition, "...unless you are pretty good you will be upset..." I am talking about recent practical experience of my own. Although I do not consider myself to be "very good", I have nevertheless not even experienced incipient "upsetness".

Metering at f/13 is going to fine for the bright sun of the day, but how does it perform at about 6am/8pm with the 2xTC without a tripod?

Wayne, I also defer to your abilities. Recently I posted a thread to do with galahs in the gloaming. Yes, this is a noisy shot because I was NOT metering the light but had it set to manual and misjudged the exposure due to screen brightness, and had to buck things up a bit in PP. However, the rest of your question applies, as it was with the 2X attached to that lens and OS on.

All I say is don't unduly scare the poster from - as I hope I do not unduly influence him into - any decision.

Anyway, good discussion.
Am.

[fess67]

Yeah I don't mean to scare the OP off from trying a converter. I suppose I should change my statement to something like - "that whilst good results are possible be prepared for a certain amount of frustration as you explore and perfect the combination".

[ameerat42]

I quite agree, Fess.
Am.