Should I get a 2x converter for my Bigma?

[MarkE70]

I'm considering getting either a 1.4 or 2x converter to use with my sigma 50-500mm lens. Does anybody use this combination? I have reservations about how this would effect the speed of the lens and the quality it produces. Any advice would be greatly appreciated. Cheers, Mark.

[glsammy]

Originally Posted by MarkE70

I'm considering getting either a 1.4 or 2x converter to use with my sigma 50-500mm lens. Does anybody use this combination? I have reservations about how this would effect the speed of the lens and the quality it produces. Any advice would be greatly appreciated. Cheers, Mark.

Hi Mark.

I've had both of these and tried them with my 50-500mm. I'm afraid I can't recommend them. Soft is the kindest description I can give to the images I got. The 2X was a definite no goer. The fact your reduced to F13 at best makes it only possible on the brightest of days, and even then the results I got were very poor. Put it this way, I no longer own either, I sold them on ebay!

[eeyore]

i agree tho the fault doesnt lie with the converters per se but with the combination

most camera autofocus requires an effective max apperture of f5.6 - tho some will function at effective f8 in bright light.

as the bigma is an f5.6 lens adding a 1.4 makes it effective f8 , a 2x makes it effective f11

thus you can add a 1.4 if you want to only use it on bright days, but adding a 2x essentially creates a 100-1000mm manual focus lens

where converters are valuable is if you have faster lenses

for instance if you had a 500mm f4 then this would becaome a 700mm f5.6 with a 1,4tc
and a 400mm f2.8 becomes a 800mm f5.6 with a 2xtc (or a 560mm f4 with a 1.4tc)

[glsammy]

Originally Posted by eeyore

i agree tho the fault doesnt lie with the converters per se but with the combination

most camera autofocus requires an effective max apperture of f5.6 - tho some will function at effective f8 in bright light.

as the bigma is an f5.6 lens adding a 1.4 makes it effective f8 , a 2x makes it effective f11

thus you can add a 1.4 if you want to only use it on bright days, but adding a 2x essentially creates a 100-1000mm manual focus lens

where converters are valuable is if you have faster lenses

for instance if you had a 500mm f4 then this would becaome a 700mm f5.6 with a 1,4tc
and a 400mm f2.8 becomes a 800mm f5.6 with a 2xtc (or a 560mm f4 with a 1.4tc)

Your spot on Pete, except the Bigma is F6.3 at the 500mm end, so the 2X becomes at best an F13.0. or should I say F12.6!!

[MarkE70]

Thanks for the advice. I reckon I will stick with my bigma for now, until maybe one day I can afford a faster prime lens. Cheers, Mark.

[glsammy]

Originally Posted by MarkE70

Thanks for the advice. I reckon I will stick with my bigma for now, until maybe one day I can afford a faster prime lens. Cheers, Mark.

That's what I decided to do as well Mark. After all, it's not a bad lens to be stuck with!

[eeyore]

Originally Posted by glsammy

Your spot on Pete, except the Bigma is F6.3 at the 500mm end, so the 2X becomes at best an F13.0. or should I say F12.6!!

good point - and more importantly this means that you can forget the AF even with a 1.4 tc which would render the lens a f9.5

i actually have used my little bigma with a 2xtc converter ocasionally with very shy species but you have to resign yourself to manual focus oonly and an awful lot of blurred shots

[Roy C]

Originally Posted by MarkE70

Thanks for the advice. I reckon I will stick with my bigma for now, until maybe one day I can afford a faster prime lens. Cheers, Mark.

Mark, there are not many zoom lenses that take a tc very well. I regularly use my 400mm f5.6 prime with a 1.4tc which gives 560mm at f8 (I tape the pins to allow AF) but this does not give me a lot more than the 500mm that you already have with the bigma.

[nitsch]

Originally Posted by Roy C

Mark, there are not many zoom lenses that take a tc very well. I regularly use my 400mm f5.6 prime with a 1.4tc which gives 560mm at f8 (I tape the pins to allow AF) but this does not give me a lot more than the 500mm that you already have with the bigma.

Interestingly enough that combo although slower at f8 does givie you an appreciable increase in reach over the bigma at the long end. The 400 5.6 with 1.4x TC is a true 560mm f8 wheras the bigma may claim to be 500mm but in reality is closer to about 460mm. So you're actually getting an additional 100mm which is often nice to have. It's a similar story with the 100-400 which is actually about 385mm at the long end.

Back to the OP's question, avoid using a 2x TC on this kind of lens. You might be able to get away with a 1.4x. I get very useable results with the 1.4x TC on my 100-400 and my 400 5.6, but the 2x demands a very high quality prime if you are to retain decent IQ - it works very well indeed on my 300 2.8 but I wouldn't bother using it on any of my other lenses. HTH!

[RogerTheCat]

I tried a sigma 2x convertor with my Sigma 150mm f2,8 macro and the images were very soft. I was very unimpressed with the convertor and got rid of it