Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Can you adjust the aperture? If so can you please give me the ranges for the maximum to the minimum.
Document: i have had this lens for well over a year since i bought it from here. i still use it about 70% of the time along with my 85mm f1.8 and 135mm f2. its a great length for indoors and the 1.8 aperture helps with indoor shutter speeds. has a short minimum focus distance, lets you take close ups of food and small objects.few cons i can think of are the edge sharpness is a little soft and it tends to back focus sometimes.
Perfect for large groups with minimum distortion. I would recommend ... be careful when shooting close because distortion of noses is always a problem when using a wide angle
Having waited a long time for the non-stoping changing of price, I decided to put the order at an barely acceptable price.The "Two-day shipping" delivery takes actually 5 days to come to me, after my leaving for a trip during which I had intended to give it a decent "debut".
This lens is going to give you that normal lens feel you had in college when you had your Canon AE-1 or Pentax. This is what I like most about this lens.Build quality is about like my 50mm F/1.4, AF is also similar. but 28mm @ F/1.8 has much more forgiving DOF.
If you're looking for a reasonably wide prime lens for indoor shooting on an APS-C sensor, this will give you a lot of bang for your buck. It's dramatically less expensive than the L series, but will get you over 75% of the quality of the L series. Whether the L series is worth the money for that last little bit is up to you.
This lens takes very sharp photos. The secret is not getting closer than the minimum distance. I have been using this lens almost exclusively at the animal shelter where I volunteer. Image quality is excellent even in lowlight situations. The lens is not heavy at all, preventing a sensation of imbalance on a camera body.I rotate this lens on either a Canon 5D or 7D.
And with the 28mm range, I can easily cram everything in.Some have complained about its weight. I, however, personally like this bulky feeling on a lens. My 50mm is really light so it almost feels like I'm holding a piece of plastic. This 28mm will give you the feeling of "I'm holding an expensive lens" which I enjoy.I know that Canon's L lens are the way to go for you experts.
I was looking for a lens that gave me clean wide view and was faster than most telephotos. This one is it. I just used for the first time this Saturday on one of my wedding shoots and fell in love with it. It has minimum distortion at the fringe, crisp and lite. This lens stayed on my cam (canon 40D) 80% of the shoot. I would highly recommend this lens to anyone who wants to have some prime lenses in their case.
In reading the reviews about this lens I really started to want one for my Canon EOS, but then I realized that for about the same money, my S95 Powershot gives me similar lens capabilities and it's a self contained camera with excellent ISO range. Probably isn't going to give quite the image quality that this lens will, but it's very impressive. I think if you're considering buying this lens and you're not a pro and don't like lugging around a your big DSLR all the time you will love the S95.
I try to work in flare as much as possible to give portraits and other pictures interesting looks. The flare pattern on the 24mm 1.4 was really great. It was smooth and beautiful. On the 28mm you can have some weird patterns and shapes which sometimes look like teardrops. It's not terrible, but sometimes you have to clone out some weird stuff.Pros:Great sharpnessVery little distortionLightweight but built wellInexpensiveCons:Manual focus isn't a smooth as an L-SeriesFlare isn't as pretty as the 35L or the 24L
Answer: Maximum is 1.8 and minimum is 22. Nice bucke at 1.8 but in a crop sensor might get a little distorted on the edges. Fun lens.