Sigma 120-300 f2.8 OS or Sigma 300mm f2.8 with 1.4 and 2.0 TC

I am having a hard time deciding between those 2 lenses. The Canon lenses or 500mm primes are out of my price range. I use a 450D.

The main focus will be bird and wildlife photography. This is why I want to use it with the 1.4 and 2.0 teleconverters. I use a sturdy tripod all the time, so I do not really care about the OS. I also read that the 120-300 would be less than 300mm at closer distances? Does the prime have the same issue?

So what lens would you choose? I only care about the performance at 300mm, 420mm and 600mm. The 120-300 range is nice to have but I don't really care about it. I use a 400mm prime at the moment and I do not have the impression that I would like to have less mm's at some times.

And what teleconverters would be best to use with it? The Kenko's or the original Sigma's?

You could buy the 400mm f5.6 L. Maybe with a 1.4x TC to make 560mm.

jvk wrote in post #13919404
You could buy the 400mm f5.6 L. Maybe with a 1.4x TC to make 560mm.

I already own a Sigma 400mm f5.6 APO Tele Macro HSM which is more or less comparable with the 400 f5.6L. I do not always have enough reach and sometimes not enough light.

I've always been led to understand that the sigma 120-300mm original was sharper at 300mm than sigma's own 300mm prime (or that if there was a difference it was minor). So the optically updated OS version of the lens should stand to being superior to sigma's own 300mm f2.8.

With a 2*TC on the 120-300mm OS I can say that you're pretty much forced to f7.1 as your widest possible aperture - you can go wider, but I've yet to see any good shots come from wide open (might be my testing, but they all look horribly soft till f7.1/f8).
http://farm8.staticfli​ckr.com …96372259_e10876​8d23_o.jpg
Canon 7D - Sigma 120-300mm plus sigma 2*TC at 600mm
f7.1, ISO 400, 1/320sec taken on tripod with OS off.

A fullsize shot and should give you some idea of its performance (and yes its a dead boring shot)

Overread wrote in post #13919518
I've always been led to understand that the sigma 120-300mm original was sharper at 300mm than sigma's own 300mm prime (or that if there was a difference it was minor). So the optically updated OS version of the lens should stand to being superior to sigma's own 300mm f2.8.

With a 2*TC on the 120-300mm OS I can say that you're pretty much forced to f7.1 as your widest possible aperture - you can go wider, but I've yet to see any good shots come from wide open (might be my testing, but they all look horribly soft till f7.1/f8).
http://farm8.staticfli​ckr.com …96372259_e10876​8d23_o.jpg
Canon 7D - Sigma 120-300mm plus sigma 2*TC at 600mm
f7.1, ISO 400, 1/320sec taken on tripod with OS off.

A fullsize shot and should give you some idea of its performance (and yes its a dead boring shot)

That is indeed a boring shot and there is not much detail. Do you have a picture of a bird or animal where you can see the detail in the fur/plumage? I can perfectly live with having to use it at f7.1/f8 at 600mm.

Not as yet sadly - I've yet to really get out and shoot well with it. However have a peek in this thread here: https://photography-on-the.net …ead.php?t=93459​2&page=124 a fair few bird shots showing off detail and if you ask you might be able to get some 100% crop views (I think there might be a few in teh thread as well dotted around) .

This is a bit of a crop from a shot a f5.6 with a 2X attached to the 120-300. I have no qualms about shooting wide open.

artyman wrote in post #13920236
This is a bit of a crop from a shot a f5.6 with a 2X attached to the 120-300. I have no qualms about shooting wide open.

To be honest, I don't consider this very sharp... Does it improve after stopping it down a lot?

freddyronny wrote in post #13920265
To be honest, I don't consider this very sharp... Does it improve after stopping it down a lot?

Then you're going to be ponying up for a Canon 500mm prime...There is nothing sharper at these sort of focal lengths without going up into the expensive Canon L primes....

Maybe look for one of the 500mm f/4.5Ls...They might be down in your price range... Cant get them fixed if they go wrong though

For the record, looks perfectly sharp to me, The bird in question doesnt have much in the way of "very fine" detail like some others, looks more like the lighting just wasnt working for revealing detail

I would definitely suggest the 120-300 2.8 OS. It is at least as sharp as the 300mm prime, and it's not just the 120-300mm range that you're not using. With the TCs and that zoom range you actually have a little headroom to work with, zooming out a bit to improve composition is worth a lot to me. 170-420mm with the 1.4 x and 240-600mm with the 2x. And even if we consider 300mm, 420mm, 600mm configurations of the prime, which may sound versatile enough, what if you need 420mm instead of 600mm quickly? Or 300mm instead of 600mm quickly? With the zoom you can achieve that in a fraction of a second by zooming out, while on the prime, you'll waste precious seconds while you need to change or take off TCs.

Of course, sharpness will never be on par with the 500mm or 600mm Canon primes. If it was, Canon's business would take a major hit... However, it is decent enough for me (especially for third to half price of the Canons), lets me crop a little without much degradation of the image, and still I'm able to print nice and sharp 8x10 or even 13x19 posters.

Here are a few shots - cropped some and processed - from my Sigma 120-300 OS and 2x TC (Canon III or Sigma APO EX DG) combo:

(There is a lot more in this thread with 100% crops as well from my combo)
NOTE: second photo was taken through my living room window. The moon shot is double stacked 2x TCs, one Canon III and one Sigma

IMAGE LINK: http://www.flickr.com …/29108710@N04/6​649880537/

IMAGE LINK: http://www.flickr.com …/29108710@N04/6​860662881/

IMAGE LINK: http://www.flickr.com …/29108710@N04/6​809858171/

Ok these shots are very impressive, especially the bird and the buck. That is the fine detail I am looking for. Which teleconverter do you consider to be the best in combination with the 120-300 OS?

Both the Sigma 2x APO EX DG and the Canon 2x III are good. They are virtually equally sharp (at least my copies) in the center, but the Canon is a hair sharper in the corners/edges and has considerably less fringing and CA (the Sigma isn't terrible it's just that the Canon is virtually free of those, it does not seem to add any fringing/CA, I think what minimal CA and fringing I see is basically just a 2x enlargement of the lens's original fringing, which is low to start with.)

Also, the magnification of the Canon is a little bit bigger due to it's distortion characteristics (the Sigma produces a tiny bit of pincushion while the Canon produces a tiny bit of barrel. These are negligible amounts, yet they result in a very minute difference in magnification.)

The Sigma 2x is more versatile though fits more lenses than the Canon that has a much larger protrusion in the front. But at least it fits my 70-200 OS prefectly as well.

gabebalazs wrote in post #13923622
Both the Sigma 2x APO EX DG and the Canon 2x III are good. They are virtually equally sharp (at least my copies) in the center, but the Canon is a hair sharper in the corners/edges and has considerably less fringing and CA (the Sigma isn't terrible it's just that the Canon is virtually free of those, it does not seem to add any fringing/CA, I think what minimal CA and fringing I see is basically just a 2x enlargement of the lens's original fringing, which is low to start with.)

Also, the magnification of the Canon is a little bit bigger due to it's distortion characteristics (the Sigma produces a tiny bit of pincushion while the Canon produces a tiny bit of barrel. These are negligible amounts, yet they result in a very minute difference in magnification.)

The Sigma 2x is more versatile though fits more lenses than the Canon that has a much larger protrusion in the front. But at least it fits my 70-200 OS prefectly as well.

Well since the difference is so small, I am thinking about the 120-300OS + Sigma 2.0 converter. Is it really useful to get the 1.4 converter too? Since the 1.4 range is actually already in the range of the 2.0 converter thanks to the zoom.

1.4TC has a much much smaller effect on optical quality. When you don't need the long reach of 600mm and only need around 420 at most the 1.4TC is a superior choice. I think gabebalazs actually uses his 1.4TC more than his 2*TC when he's shooting his birds from the window (or a hide).

What body are you using?

I'd agree that the 1.4x would likely be more useful, with better image quality. Getting the 2x as well would be nice when you need the 421-600mm range.

I'd also look for used Sigma 500 f/4.5 lenses. I picked one up a few years back for a price I still can't believe it was offered for! Should also be found around the same price point as a Sigma 120-300 2.8.