Filter Reviews

First the technical data
Specifications

Filter Size 77mm
F-Stop Range 2.8 - 32
Minimum Focus Distance 72" (6')
Magnification 1:7.8
Zoom/Focus Control Two-Touch (Twist)
Angle Of View 43.3 (70mm) - 12.3 (200mm)
Groups/Elements 14 / 17
Length 7.1"
Max. Diameter 3.4"
Weight 49 Oz.
Specialties "Hyper Sonic Motor" For Quiet And Smother AF, Instant Manual Focus Override In AF Mode, Low Dispersion Glass, Non-Rotating Front Ring, Tripod Collar

I have owned this lens for about a year now in the Canon EOS mount. When first considering this lens, I debated over buying it or the more expensive Canon version. After reading numerous reviews, it was obvious that many other users felt this to be a great lens, comparable to Canon's, but at a much lower cost. So, I decided to get the Sigma version. I have never been sorry for that decision.

I should note that I have used both this lens and the Canon equivalent, so comparisons can be drawn from this. I have not used any comparable Nikon or other lenses in this focal range.

This lens allows for great versatility. There are numerous scenarios in which this lens performs well. Below are just a few.

Positives
1) The 2.8 aperture allows for great low light photography, or dusk/dawn outdoor photos
2) In the 85-135mm range, the constant 2.8 aperture makes this a very good portrait lens; throwing the background out of focus and making the subject stand out.
3) With the Sigma 2x APO teleconverter, this lens becomes a very nice 140-400mm 5.6. It will still autofocus with all Canon EOS bodies, and produces sharp photos despite the 2X converter.
4) High Speed focusing motor, rivals Canon's USM technology
5) APO, low dispersion glass produces top quality images with clear, contrasty images
6) Full time manual focus
7) Tripod mount is included, something that Canon will make you pay for...
8) Very sturdy lens design, solidly constructed

Negatives
1) Tends to hunt just slightly more than the Canon Version. This is easily overcome with full time manual focus
2) When the hood is attached in the "storage" position (reversed on the end of the lens) the full time manual focus ring is hard to manipulate
3) HSM is just slightly slower than USM (Canon's ultrasonic focusing technology)
4) Lens is heavy, but so are all similar lenses. I suggest a monopod if prolonged use is expected

...

Sigma also has a new 100-300mm F4 lens that is similar in quality and design to this 70-200mm version. If you tend to stay at the longer focal lengths and don't need the extra 2.8 f stop, then I would suggest looking into the 100-300 F4 lens that is new to the market.

Overall, I am very happy with the performance of this lens. In my opinion it is well worth the price tag and with the money you save over the Canon version can be spent it in other areas. I used the extra savings to purchase the 2X teleconverter and a few 77mm filters.

...Thanks for your time...

Performance:
This lens couldn't be much sharper at 15mm, it is pristine. Softer at 30mm, though still better than average corner to corner. I like that it seems optimized for 15mm. Very impressive, Sigma. Some flare, but any 15mm zoom is really prone to that. f3.5 is a little slow, but at 15mm 1/15 sec works for handholding, so it isn't a problem. Incredibly deep DOF at 15mm, makes for spectacular foregrounds, sharp from your feet to the horizon (at least with a cropping DSLR). 8 blades is very respectable for a lens of this price and not much is usually OOF.

Build:
Superior. Suprisingly light for it's size. Fast AF. The 82mm front thread is accomplished using a felt lined cap that slides firmly over the permanent pedal hood. A little awkward but it works a lot better than it sounds. No vignetting with an 82mm front filter using a cropping DSLR at 15mm, I doubt the same would be true with full frame where the angle of view is really uncanny.

Overall:
Arguably the best in its class, great price makes it even better. Everytime I see the images I thank myself for buying this lens.

Sigma 20mm EX is an exceptionally well made lens. Performance is extremely satisfactory. It is almost indispensable for me to go without it when I am outdoors. Takes very good wide angle shots of buildings, parks and friends and family picnicking in the park. Shots have come very sharp and crisp with edge to edge brightness and sharpness. 20mm wide angle focal length gives you a very large depth of field which is essential for taking shots of wide open outdoors, filling your frame with a large expanse of ground/sky. Fast f1.8 aperture will let you take snaps indoors in natural light and hand-held shots of lighted buildings etc. in night time. Rear focusing feature of this lens results in fast AF and also the length of the lens remains same. Macro shots of subjects will give you convex mirror type of fascinating images and one can produce far more interesting effects depending on one's creativity.

Indoor flash photography may give rise to vignetting due to ultra wide nature of the lens as most flashes cover only 28mm span. This may probably be solved by using a wide angle attachment on the flash which to my disappointment was not available for my flash (Pentax AF-280T). Also 82mm filters may prove to be expensive. But I think a filter is essential for this lens as the front element glass is very near to the filter area.

All said this is an extremely satisfying buy (most bang for bucks) which gives you great results.

It as sharp as any prime at any focus length.
It smooth and perfectly lies in the hand.
It exhibit the BEST optical performance you can imagine.
It is HIGH resolution lens, it is of imperative for digital photography.
It looks cool and perfect cosmetically! :-)
It is durable one!
BTW, take EX 82-mm UV multicoated Sigma filters! They are the best I ever seen in my life! No seriously, Heliopan, Hoya, Tiffen all of them could not handle candle for Sigma in this regard!

This is aspherical zoom lens is a 2 in 1 zoom lens taking care of 28-70mm and 70-210mm zoom lens so no more lens changing hassles.

The results from this lens has come out very well and the crispness, clarity, exposure and sharpness are quite satisfying.

It's quite compact and lightweight but not as light as the Tamron's 28-200mm. But then I guess weight does add sturdiness and strength to a product.

It's got a very good aperture range of 3.5-5.6 for such a huge focal range. The aspherical design has added to it's compactness. Due to the non-rotating filter mount, using of polarizers has become easier.

On the downside the depth of field is the only casualty in the mid to tele range compared to smaller range zooms.

Since no one has had a chance to review this product I thought I would share my experiences. I have always been impressed with the size of projection tv's but their picture quality is usually terrible unless you have them in a dark room. My opinion changed when I had a chance to review similar makes and models and got a look at this 48" Sony projection television. I could not believe the picture and sound quality coming from this unit. I was also very impressed with the two tuner pip feature. Most tv's contain only one tuner so a vcr or dvd is required to use this feature on other tv's. The other advantage to this model is the limited space one needs to be able to view it properly. I presently live in an apartment and space is limited. The room size is about 13' X 12' and this model fits well into the room without being over powering. Other advantages include full surround sound with adjustment features, three different video settings and an extremely easy to use remote control. I would definitely recommend this television to someone interested in purchasing a model larger than a 36" television. Take a look I'm sure you'll agree, Sony has done a great job on this affordable product.

This television has redefined the entire category of projection televisions. Typically, a big screen was purchased with the understanding that you were getting quantity (screen size) over quality (picture quality). This set from SONY has completely blown away this theory. I am so convinced that this is the best non HDTV on the market that I not only used to sell them, but I broke down and bought one for myself. It is truly a viewing experience that you have to see to believe. It defies not only the quality vs. quantity issue, but it also defies the big screen viewing angle issue. You can have a great, clear view of the screen from just about any angle. I could go on and on but time is at a premium. Trust a former electronics salesman when he recommends this television to headline a great home theater. Couple it with a quality dvd player with some surround sound and you will have a better theater than the local cineplex. Pull out the extra dough and make this the centerpiece of your entertainment universe.

This is a good set from SONY. It has a Digital comb filter that increases picture resolution and reduces noticeable dot-crawl, which is visible on less expensive 27inch brands. It has Rear audio and composite video inputs as well as an S-video input for DVD, Laser Disc players and Super-VHS recorders for higher picture resolution. It also has XDS, which has become a standard feature of late on better TVs. XDS receives information that some broadcasters are sending with their signals. It also comes standard with Clock, Sleep Timer, Channel Jump, Remote and V-chip. I just saw this set this weekend with a satellite signal and DVD demo. It looked very good.

This adapter ring is just what the camera needs, not only does it keep grit out of the works and add balance to the camera, it also gives you a good place to hold the camera, making it feel much more natural.

I live in the Upper Peninsula of Michigan and wanted to take pictures while it was snowing, but didn't want to get snow and water in the exposed zoom lens part of the camera so I ordered the Lens adapter ring and a set of 52mm lens filters that screw onto the filter. Now the internals are safe.

If you are looking for an accessory to add a little something to your S75/85, go with the adapter ring and a protective filter.

It is designed to be used for 37mm camcorders, but I bought mine for use with a digital camera (a Sony DSC-P50). It does the job very nicely. Note that the lens is large when mounted on a DSC-P50, and it will block the flash in the lower left of your frame. However, I found that if I was using the flash outdoors as fill-light, then the shadowing was negligible. This lens is a wide angle, but not quite a fish-eye. I enjoy the slight distortion it lends to my images (eg. curved horizons etc.). At any rate, this lens is very inexpensive, and if you're wanting to experiment it will do the trick.