Day 1

I received my new Sigma 150-500mm f/5-6.3 OS yesterday (a day earlier than UPS expected) so I made a quick run out to the neighborhood duck pond to see what I could do with the lens on my EOS 40D camera. Here are a few sample images. The files ending in –crop are actual pixels crops from the 40D with no post processing. The camera was set to faithful picture style with contrast and sharpening turned down as far as they would go. The other two parameters were left at default. The –ff files are given to show what the full frame looked like without any post processing. The –web files have gone through post processing (levels adjustment, color correction where I felt it was needed and sharpening). The –web files also have the EXIF data intact.

My first thoughts on the lens are that the auto-focus seems quite quick but the lack of a focus distance limiter switch is disappointing.

The OS seemed to work well and in my short time shooting with the lens so far I found that I could get hand-held shots at 1/125 sec that looked acceptable without too much trouble.

On many photos I noticed a sort of “glow” effect in some of the slightly out of focus areas in the photo. This reminded me of what I saw with the Canon EF 70-300mm DO lens and was not pleasing to my eye. The crops of the goose head show this effect along the top of the head and as you can see the effect diminishes as the lens is stopped down similar to the 70-300 DO lens.

So far my impression of AF accuracy at the 500mm setting is that the 40D seems to struggle a bit to lock focus when the lighting gets at all tricky. My guess is that this has something to do with the lens having a max aperture of f/6.3 at 500mm and the AF system of the camera being designed to only work with f/5.6 or faster lenses. The AF seemed a lot less sure-footed than that of my EF 500mm f/4L IS USM (not that this is a surprise). Hopefully as I have more time with the lens I will be able to get a better feel for the AF and will be able to use it more effectively at 500mm.

---------------------------------------------------------------------------------------------------


Day 2

Today I had a chance to take do a “real” photography outing with the Sigma 150-500 OS and I think I am getting more of a feel for the lens. Photos from day 2 start with _mg-0527-web (shot of a young Purple Gallinule). The weather was scattered showers and the lighting got pretty low at times which meant I got to really test out the OS. I also was reminded of how nice it is to have a faster lens at 500mm than f/6.3!

Overall I think the lens did very well, autofocus still feels nice and fast though there were some times when a focus limiter would have made a big difference in catching some flight shots that popped up unexpectedly.

In the lower light conditions I really started feeling the limitations of the 40D’s AF system with a f/6.3 lens and noticed that my keeper rate was by my estimation about 40% of what I normally would get with my 500mm f/4L IS USM under similar conditions. I don’t think that performance is bad considering that the Sigma is over a stop slower in max aperture at 500mm. When the 40D did lock focus I was generally impressed with the results in terms of detail rendered though the contrast of the lens isn’t as good as the L primes that I typically use (again for a sub $1K lens this isn’t a surprise).

Another optical quality that I noticed again was the “glow” that occurs in my photos in the slightly out of focus regions of the photos. This is mainly apparent at 500mm and f/6.3 (the main setting I plan on using the lens at) and it diminishes rapidly as the lens is stopped down and seems to be fairly well gone by f/9 or so. A good example of this is in the butterfly shot (_MG-0961-web) in the high-contrast areas around the edges of the slightly OOF Spanish moss. Personally I find this objectionable but I suppose there are worse optical problems that could occur.

I did shoot for a while with the EF 400mm f/5.6L USM to compare its performance to that of the Sigma and I must say that the prime continues to be an amazing lens. My impression is that the prime delivers better sharpness and contrast along with better consistency in terms of auto-focus. With the prime my keeper rate went up to about what I expect from the EF 500mm f/4L IS USM.

This isn’t an ideal comparison but _MG-1031-web and _MG-1055-web were shot with the Sigma and the Canon respectively. The lighting conditions were the similar and the distance to target was the same.

I didn’t get many opportunities for flight shots in reasonable lighting but the couple of chances I got did yield pleasing results. The crops from today have seen some post processing (levels adjustment and sharpening) but are actual-pixels crops. I was very pleased with the amount of detail rendered in _MG-1246-crop. In my mind this proves that the Sigma can be a capable flight photography lens.

The Sigma also seemed to be a pretty decent pseudo-macro lens with its long focal length and relatively short minimum focusing distance (2.2 meters). However, as can been seen in _MG_1254-crop the “glow” in the high contrast areas around the flower is readily apparent at 500mm and f/6.3. The amount of detail seemed pretty good to me though and things only improve on stopping down as can be seen in _MG_1873-crop.

After a good deal of shooting with the lens today I have the overall feeling that the Sigma 150-500 OS is a capable lens and a decent value for the money. One other note, all of the images in this gallery are hand-held shots.

---------------------------------------------------------------------------------------------------

Day 3

After three days of shooting this lens I think I am starting to get a good feel for it and its quirks. Today I had a lot of light for the most part and tried to spend more time with the lens stopped down. Stopping the lens down to f/8 seems to help the image quality at 500mm significantly and I am much more pleased with the results I got at f/8 than what I was getting at 500mm and f/6.3 for most shots. When the lighting and composition are right f/6.3 at 500mm does deliver what I think are acceptable results but so far I have found those conditions are met less often than I would like.


The glow and “bad bokeh” that I have been seeing in my pictures seem to be more apparent in bright/high contrast lighting. In _MG_2611-web (which was taken in direct sunlight on a bright afternoon) you can see some of the qualities that I find objectionable. To start, look at the leaves in front of and behind the bird. There appears to be quite a bit of a double image along the edges of the leaves. Also near the tip of the bird’s beak where it is starting to get out of the DOF you can see the “glow” starting to show up. Certainly I had enough light to stop the lend down to get more of the beak in focus and reduce the “glow” effect but as can be seen in _MG_2631-web even at f/11 there is some glow at the tip of the beak and the double edges of the leaves are still present. The rest of the background also starts to look quite displeasing to my eye when stopped down and this can be helped by getting a lower angle on the bird, however in this case it would require lying in the mud at the edge of a pond full of American Alligators ;).


When I used the lens wide open at 500mm in shaded areas as in _MG_3407-web I found the effects to be drastically reduced. Fortunately the OS seems to work quite well and I was able to fairly consistently (~60% of the time) get hand-held shots at 500mm at shutter speeds in the 1/50 – 1/60 second range. The success rate dropped off fairly drastically at shutter speeds slower than 1/50 sec. In my experience this is probably a stop or so better than what I have been able to do with the EF 100-400 IS.

Another thing that I am still adjusting to is the fact that the Sigma is a zoom lens. There have been several times over the past couple of days where I could have used a shorter focal length to get a better shot and it didn’t occur to me immediately to back off on the focal length. The zoom, after all was one of the major reasons that I was interested in the Sigma lens. One somewhat irritating thing for me is the stiffness in the zoom ring and the fact that it turns in the opposite direction that I would expect it to. For me quick operation of the zoom mechanism is not really possible. Maybe with time the zoom mechanism will loosen up and I will be complaining that the lens keeps flopping out when I don’t want it to LOL. This does, however, remind me of how much I like the push-pull zoom mechanism of the 100-400 IS that not only allows for quick and easy zooming but also allows me to lock the focal length at any setting within the zoom range.


At this point I think I have a good feel for the Sigma 150-500 OS and that I am ready to do a little comparison shooting between it and my 100-400 IS. Overall I think that the Sigma offers an awful lot for the price (considering what is available from Canon in this price/focal length range) and I have seen that the lens can deliver good images. The Sigma does not appear to be as good optically as the Canon primes when used wide open but then again it offers features that the primes do not and at a lower cost.

I am starting to get the feeling that for my personal needs that I will need to do most of my shooting stopped down to at least f/8 to get results that I am really pleased with. I don’t know if this will be too limiting. I think what it will boil down to is weather or not I am getting added detail/optical quality over the 100-400 IS.

---------------------------------------------------------------------------------------------------

Day 7

After spending several days shooting with the Sigma 150-500 and a few other lenses (including the EF 100-400 IS and EF 400mm f/5.6L) I have decided not to keep the Sigma. My initial plan was to replace my 100-400 IS with the Sigma and carry it with me on my second 40D body along with my EF 500mm f/4L IS USM w/EF 1.4x TC on my primary 40D to get the close in shots that wouldn’t be possible with the extreme focal length of the prime setup. My hope was that the Sigma lens would offer better image stabilization, faster AF and a better focal length range than my 100-400 IS offered.

What I saw with the Sigma lens was that it offered very similar optical performance to the 100-400 IS under most conditions. However, at the long end of the focal length range (at or near the 500mm setting) and at large apertures (~f/6.3) I noticed that many of the photos that I took had a glow effect in the slightly out of focus areas of the image. This was especially apparent in bright lighting and in the vicinity of high-contrast areas of the image. This is not something that I see in my images from the Canon zoom.

Another area of concern for me was the AF performance when the Sigma lens was used at the long end of its focal length range. I noticed that on my 40D camera that the auto-focus system seemed less sure-footed than it did with the 100-400 IS under the same conditions. The Sigma lens tended to hunt more and to lock onto unintended targets with higher frequency than the 100-400 IS did. Furthermore, the lack of a focus distance limiter meant that when a focus excursion did take place it usually took longer to recover from with the Sigma lens (provided that the limiter was turned on with the 100-400 IS).

On the positive side for the Sigma the OS system did seem more effective than the IS system in the Canon lens. After doing a lot of playing around I came to the conclusion that the Sigma lens could be hand-held with about a stop less light with decent consistency than the Canon lens can.

I did find the Sigma lens to be a bit more awkward to carry around as it was heavier and the lens strap seemed to mount in an uncomfortable way for me. Furthermore, I found that I prefer the push-pull zoom mechanism of the Canon lens to the twist-style zoom of the Sigma.

With all of this in mind I decided to stick with the Canon lens that I already had and pass on the Sigma. I think that under most conditions and with most settings the Sigma lens offers very similar performance to the Canon zoom and it costs over $400 less. It would probably be worth considering for someone who is looking for a telephoto lens with decent optical performance and stabilization without breaking the bank. If you already own a lens like the 100-400 IS or the EF 400mm f/5.6L USM… the Sigma probably wouldn’t be worth adding to the collection.