Sigma 50-500 OS vs Canon 100-400 IS

[Tonym]

has anyone used this lens? I can get a reasonable deal on a canon 100-400 IS but was wondering if the extra reach of the Sigma 50- 500 might be better for wildlife. I have looked at the Canon in a few stores and all the info I have read about them seems good and the Canon is a f4.5-5.6 compared to the Sigmas f4.5-6.3, would this make a great deal of difference?

[twister]

Most canon cameras wont auto-focus if the wide-open aperture drops below f/5.6

[ricktas]

What twister means is that if your largest available aperture is 6.3 (the sigma) at the 500 end of the zoom range, there is the risk that your camera may not auto-focus. The Canon 100-400 gets great reviews, I would go that way.

[Riverlander]

I have the Sigma 50-500 OS - had it for just over a week. It autofocusses without any problems -- Sigma have developed a chip (in the lens) which "lies" to the camera, so that the autofocus works at f/6.3. It will hunt a bit in situations where there is no contrast -- so did my 100-400 that I sold about 12 months ago.

The weather here has been crappy, and I have not tested the lens properly yet, but I have got some good bird shots at the 500 end at f/8. Sunshine and warmer today and tomorrow

The extra 100mm can be very important if you are a birder and need to crop the images later.

[twister]

Thanks for clarifying Rick!

Riverlander, thanks for your update as well...I wasn't aware the lens still reports itself as 5.6 even though at the longer end it is 6.3...

[Big Pix]

this was shot using the Sigma 50-500.....
http://www.ausphotography.net.au/for...ad.php?t=65636

[Kym]

The 100-400 is by all reports brilliant, look at Richard Hall's bird posts for examples. Top notch.

These are my recent efforts with the 50-500 on Pentax - no AF issues at all (unless that is a Canon thing)
http://www.ausphotography.net.au/for...ad.php?t=65553

[kennchris]

I have a 100/400 canon and my daughter-in-law had the 50/500 after doing comparision shots she sold her lens and brought a canon.

[Tonym]

Mmm thats interesting, what were the comparisons? did you crop pics at full zoom? did the extra 100mm make any difference for pics at a distance?

[Riverlander]

Tony
This thread of mine shows some bird shots. You can see the ones taken at f/6.3 are not as sharp as they could be but the f/8 ones are very good.
http://www.ausphotography.net.au/for...ad.php?t=65762

I still have not done any focus micro-adjustment, but will look into it when we get a really nice day.

[Tonym]

Tony
This thread of mine shows some bird shots. You can see the ones taken at f/6.3 are not as sharp as they could be but the f/8 ones are very good.
http://www.ausphotography.net.au/for...ad.php?t=65762

I still have not done any focus micro-adjustment, but will look into it when we get a really nice day.

Wow there are some great shots there. I was a bit puzzeled by the bit soft comments but after looking at them I can see the slight difference between the f/6.3 and f/8. I keep thinking the extra 100mm of the Sigma is a definate plus and will sway me towards one.

[Shelley]

I had the 50-500 - a brilliant lens in the right hands. Focus is slower than my current lens. But, for me it was hard to get sharp shots hand held as I wanted the option of hand-held. It got heavy for me and did affect my photo-taking after a while, I am not very big and my hubby reckons I am a wimp. So, I bought the 400 5.6L and haven't looked back. It has beautiful bokeh and the zoom is handy (50-500 sigma that is).

I dropped the reach and also went to prime - but it has not bothered me at all as I like to move around and get closer. Purely used for birding.

[Analog6]

And one of our site sponsors, NG systems will give you a great price on the 100-400, I bought mine from him

[ving]

i have the sigma 150-500 OS. not a bad lens at all. it wont beat the 100-400 L for sharpness, but the reach is good and it does everything i need. I believe it focuses at f5 rather than F6.3. I think it was kym who said that the aperture in new lenses doesnt change as you zoom and focus, but closes to 6.3 when the shot is taken... or something.

anyhow i have stacks of shots on this forum you can look at

[pauldshearer]

I am leaning towards the Sigma lens rather than the Canon

[Speedway]

I have the 150-500 Sigma and have had no problems with auto focus I usually use it in AP mode set to F8 for birding and wildlife. Although the canon is the better quality lens if you can afford the extra I am quite satisified with the sigma.
Keith.

[Tannin]

I was a bit puzzeled by the bit soft comments but after looking at them I can see the slight difference between the f/6.3 and f/8.

Tony, if you can really see the difference in sharpness between two shots from the same lens at f6.3 and f/8, then there is no way you should consider the Sigma over the Canon - and indeed no way that you should consider anything except an L class prime (or the equivalent Nikon).

But that's not what's going on in the shots that you have looked at. What you are seeing is either:

(a) the extra depth of field which has (i) more of the subject in sharp focus and (ii) is more forgiving of a slight mis-focus, or:

(b) the better lighting conditions for the f/8 shot. No-one (well, hardly anyone) shoots at the long end of a high-ratio zoom lens wide open as routine. In fact, you generally don't use the widest aperture of any lens as routine unless the lens is an absolute diamond-crusted beauty (such as the very best Canon super-tele primes like the 600/4). These are around $10,000 each.

Most experienced photographers will stop down a fraction if they have enough light to do so, both for increased depth of field, and for slightly better sharpness - though that second reason is arguable with good quality glass.

What this means for your f/8 to f/6.7 comparison shots is that that f/8 shots were most likely taken in good lighting conditions, where the f/5.6 and f/6.7 shots were taken when the light was marginal (otherwise the photographer would have stopped down a bit). Not every single time, but most of the time this will be so.

In reality, you are almost certain to find the Canon slightly sharper. But don't stress out about that. It is a very, very good photographer who can find the limits of either of those two fine lenses.

Me, I'd pick the Canon. It has traditionally been sharper than the various Sigmas, though this latest model may well have caught up, and in any case the difference will be small. However the Sigma weight nearly 2kg - that is a lot heavier than the Canon (1380g) and you will not be able to hold it as steady for as long.

Second reason is focus. Auto-focus mechanisms on any brand of camera need the as much "leverage" as they can get. SLR AF systems calculate the correct focus distance by comparing the view through the "outside" of the lens to the view through the "centre" of the lens.

(That's not quite true, but it's a nice simple way to think about it which will still give us a good practical understanding, and the correct explanation gets pretty arcane and technical. I think I wrote it up in detail somewhere here once upon a time.)

Anyway, the take-home message is that the wider the maximum aperture, the better the focus system works. Nothing to do with Canon or Pentax bodies, nothing to do with Sigma or Nikkor lenses, just the basic physics of phase-detect auto-focus. (Contrast detect AF, as used on cheap P&S cameras, doesn't need or use this "leverage" - but contrast detect AF is very s-l-o-w and probably not as accurate.)

I get a graphic illustration of this every time I add or remove the 1.4 converter from my 500/4/ Bare lens, it focuses faster than you can blink. It is amazing! With a 1.4 converter it becomes a 700mm f5.6 lens, and it takes a lot longer - say around about the same as a 400/4.6 or a 100-400. And pop on a 2X converter and it won't focus at all on a consumer body, only on a pro-level body with a pro-level AF system. Even so, it is very slow indeed.

I believe it focuses at f5 rather than F6.3. I think it was kym who said that the aperture in new lenses doesnt change as you zoom and focus, but closes to 6.3 when the shot is taken... or something.

Definitely "or something".

There are lenses which can actually meter and focus at f/5. In fact, there is a special term for this sort of lens. It is called "an f/5 lens".

If it was possible to meter at f/5, it would be equally possible to shoot at f/5. What Mr Not-Kym (Mr Not-Kym 'cause I don't reckon Mr Kym would have got this one wrong) was presumably thinking of is modern focusing and metering where the shooting aperture is smaller than the maximum aperture. If, for example, you are shooting at f/11 with a 24-105/4 lens, what you see through the viewfinder is the f/4 view; what the camera meters with is the f/4 view (it does the sums from there to work out what exposure is required at f/11); and what the focus system focuses with is the f/4 view. The camera is smart enough to leave the lens wide open all the time except for the last moment before the shutter fires (which you can't see anyway because the mirror has already flipped). The only time you ever see the stopped-down view is when you press the DOF preview button.

This applies to the Sigma the same as it applies to every other lens ever made. (Er ... sorry ... before about 1970 cameras and lenses were fully manual. You had to do everything, including manually turning the aperture ring to dial up f/11 or whatever you wanted.) I'll try again ....

This applies to the Sigma the same as it applies to every other lens made since about 1970. Regardless of the aperture you are going to shoot at, the cameras focuses at the maximum aperture available to it with the lens and focal length selected. In the case of the Sigma, that's f/6.3. You get f/6.3 "leverage" which is a bit less than f/5.6 "leverage" and a huge amount lefs than f/4 or f/2.8 "leverage". (They don't call fast lenses "fast" for nothing!)

So:

Pro Sigma: 100mm longer.
Pro Canon: faster, better focus, much lighter, possibly better quality.

I have no doubt that the Sigma is a fine lens, and wouldn't be upset to see you buy one. My leaning, as I said, is to the Canon, but only by a small margin. They are both good choices.

Enjoy!

[jim]

I'd be careful. I've heard that the 100-400 is soft.

[Pine]

I'm biased, so I naturally favour the 100-400mm Canon.

Here's a few recent images I've posted taken with this lens.

Red-capped Robin

Weebill (Australia's smallest bird)

Baillon's Crake

Superb Fairy-wren

I like your shots in particulary the Baillons' Crake!

Regards

[Bennymiata]

You really should go to a camera shop and try both of these lenses on your camera, and hold them up to your eye for a few minutes each and take some snaps to look at when you get home.

While on paper, 700 grams difference in weight may not seem much, after holding them up for a few minutes, or walking around with them on all day, you WILL feel the difference.

One thing I've found with birding is that you are not always at full zoom, as you need the lower end of the zoom to find your subject, then you want to zoom in quickly to get the shots.
The Sigma takes a lot longer to zoom in using the twisting ring than the Canon does by using the push-pull system.
I wasn't so sure about the push-pull system of the Canon until I bought one and now I think it's a great way to zoom.
If you also need to tweak the focus, on the Canon, you don't need ot move your left hand as the push-pull also works the focus by twisting, whereas on the Sigma, you have to move your hand and find the focus ring.

If you find you don't like it, the Canon has by far the better re-sale value too.