Sigma 120-300mm

[Duncan Wilson]

I use a Canon XL1 for wild bird video, mostly with a Sigma 400mm f5.6 prime. I'm looking to buy a tele-zoom, and the Sigma 120-300mm f2.8 EX seems like a good option. It gets excellent reviews from still photographers and looks good value for such a fast lens. I know it weighs a ton, but this doesn't overly bother me.

I don't have the option to try before I buy, so I'd be interested to know if anybody has used or has views on this lens as an option for the XL1.

Cheers

Duncan

[Steve Nunez]

Duncan-

you might wanna look at the Sigma 50-500 too- it's a powerhouse lens that astounds reviewers constantly as normally zooms of this type perform horribly- but the Sigma 50-500 is a stand-out lens in that it's sharp, contrasty and produces accurate colors- take a look at it- you might find it's range perfect for the videography you do.

[Duncan Wilson]

HI Steve
Thanks for the reply. I have been thinking about the Sigma 50-500mm lens and it is definately an option (as is the Canon 100-400mm L). What attracts me to the 120-300 is its speed - constant maximum aperture of f2.8 at all focal lengths. As I recall, the maximum aperture of the 50-500mm is f4 (at 50mm).

I guess it's a question of whether those extra couple of stops are worth the price differential.

Cheers
Duncan

[Jeff Donald]

I've never been too impressed with Sigma lens for film work. I've tested many of them and compared to the similar Canon lenses, the Sigma's rarely preform near as well. However, the latest crop of their hi-performance lenses (made to compete with the Canon L series) are a big improvement. The L series lenses still perform better in most aspects, but Sigma has closed the gap. Sigma lenses on video (read low resolution) should perform very well. If you intend to use the lenses on both still cameras (film or digital) and video, the Canon's would be the better choice in my opinion. Canon's L series are built better, have better resale value, and most importantly, better optics.

[Duncan Wilson]

Jeff
Thanks for the input. The only Canon lens I have used with my XL1 is the 100-400mm L, which I borrowed for a couple of days. This wasn't enough to really get to know it, but I didn't see a significant difference in image quality versus my Sigma 400mm (other than rather colder colours which I guess is a matter of personal preference). As you say, however, video resolution is lower than film, so it may not be possible to appreciate subtle differences in quality.

My primary interest in the Sigma 120-300 is its speed - dreary British winters and late evenings in reed beds tend not to be too kind light-wise. I'm not aware of a Canon zoom that offers f2.8 at 300mm, and the Canon 300mm f2.8 prime costs four times the price.

I guess my main concern is whether the DOF would be workable with such a wide aperture. I don't want to pay-up for a super-fast lens only to discover that I need to stop down to get a usable DOF.

Regards
Duncan

PS Great website!

[Jeff Donald]

If you're not going to be using the lens for digital or film still work the Sigma should be fine. You can white balance to a pale blue color to warm the shots a bit if you like. It's easier than filtering all your shots in post. If you're not in a big hurry, wait a month or so for the big photo trade show in Las Vegas (PMA). Canon is expected to announce several new lenses. I'm not sure if it will be of interest to you, but you might kick yourself if Canon announces your ideal lens and you just bought the Sigma.

You correct that if you really need the F2.8 speed then the Sigma is probably your best option. DOF will be very shallow. With distances from 3 to 8 meters or so, you'll only have several inches of DOF. What are you're typical distances from camera to subject?

[Duncan Wilson]

It totally depends on the subject. If I'm doing close hide work, it can be down to 3 metres or even less, but more typically in the 10-30m range.

[Jeff Donald]

In the 3 meter range your DOF will be only several centimeters when your at F2.8 If the bird isn't parallel to the film plane (chip), depending on where you focus the beak or tail may be out of focus. At the longer distances, focus will be critical, but your DOF will be 1/2 meter or more depending on your aperture.

[Mike Murri]

At 40X wide open at 2.8 your DOF is so minimal, at any distance from the camera, I wouldn't make this decision based on f-stop alone. I work at the extreme limits of lenses and power with birds all the time, and trust me on this, DOF is needed, badly, especially when working with flying, landing, or feeding birds. Simply, just trying to acquire birds in the view finder at these magnifications is difficult enough with the greatest amount of DOF. Granted, at 50mm (or 7X on XL1s) you could acquire your bird with ease...then zoom up to 300mm (or, roughly 40X on XL1s) and this would be a huge andvantage over using a prime 300mm but, I'm telling you, even at f8 the DOF is critical that filming moving birds, especially flying ones, become almost impossible to track and maintain focus.

I use my Nikon 600mm f/4 AFS at f/22 all the time on my XL1s to film wildlife, mostly ducks, tucked in, slicing up the sky, landing on water and ice. At minimum f-stop it is all I can do to just acquire, track (smoothly) and shoot. And, amazingly, at sunrise or even before (a little) and well into and a bit after sunset. I have yet to find a scene that requires a maximum f number, be it f/2.8 or even my f/4 lenses.....rarely do I go beyond f/16. Although, on my 35mm camera, it never leaves f/4.

Hopes this helps.

Mike

[Jeff Donald]

I agree with Mike that you might not have a wide enough range to find your subjects easily. I use a 50 to 300mm lens, sometimes with a 2X convertor. On the XL1 I use the Canon 35 to 350mm the most. The speed has never really bothered me. The effective ISO of the XL1 is about 320 and sometimes I use the -3db gain to control the contrast a little more. But with 1/2 a meter DOF at 30 meters I don't have a great deal of difficulty focusing. Flight shots are a challenge, I usually sacrifice a little magnification for more DOF, and easier tracking of the subject.

[TingSern Wong]

Very interesting discussion. I have a Sigma 50-500mm for which I used for filming on Mt Everest and birds as well. I guess I am asking for it, but, I put a 2X teleconvertor on it too :=). Especially from Everest Base Camp (Rongbuk), I could capture climbers going on summit of Everest (22km away).

BUT, at such extreme range, I found atmospheric distortion (caused by moving air) a big problem. Also, nailing the camera with that 50-500 and 2X telec requires more than just one tripod. I needed two of them, using a long lens holder clamped on the Sigma just to hold the rig steadily.

However, there is nothing I can do with atmospheric distortion - which makes the image move like an ocean wave.

I have used the Sigma 50-500 without telec - the images are sharp ... but, at 500mm, it is alomost impossible to hold focus if the object is near and of significant depth. The DOF is simply too shallow (like a true macro lens in 35mm photography). When videoing a large bird (cranes, for example), if the head is sharp, the tail will be totally blur (if viewed head on).

Also, it gets very hard hunting for the subject ... basically, I have to use the following -
a) Zoom out to 50mm to locate the subject within the viewfinder
b) Zoom in to 500mm to focus (I use an external LCD monitor for that - Canon standard issue Colour viewfinder not sharp enoug)
c) Zoom out to compose and then start filming ...
Errr, provided your subjects stay still this whole time !!!!

Sometimes, I prefer to use the lighter Canon EF 75-300mm for this. The Sigma 50-500 is very heavy compared with Canon.

TS