Originally I was looking at this for external architecture and museum interiors. I am amazed at how close your able to get to the subject and still capture everything. The ability to take in 180 degrees is great, and with software your able to remove the fisheye effect if needed.

Great quality and construction finish; Feels like a fine instrument; Dead on instant focus - no hunting; Great bag/case

None

An unusually well made fun lens which has full metal construction even the inner barrels.

Full metal barrels; decent sharpness across the frame

Visible CA

This is a very fun lens to use. It provides full frame images on a digital slr through the entire zoom range. It is about the equivalent of a 15-26mm lens on a 35mm camera. It is a great match for the 18-55 kit lens that comes with most Pentax digital cameras.

Compact size; Good quality optics; Smooth operation; Zoom

No filter system; Only useable on digital cameras

This lens is included fisheye function 180 degree at 10mm and ultra wide 100 degrees at 17mm. Sure, there is lots of distortion in 10mm because it is fisheye, but it is not a bad point you cab create many creative photo from it. At 17mm, you can take 100 degree with just a few distortion.

Both fisheye and ultra wide in the same lens; good build quality

Cannot install filter; an unique design of lens cap if lost it have to pay much for it

Traditionally fisheyes are often used for aerial-, underwater- and some kind of indoor photography. Due to the uncorrected extreme field-of-view the fisheye perspective can produce some oooohs and aaahs from your audience but it shouldn′t be used too often in presentations because the effect of...

This lens is so fun! I bought it at first with some hesitation that I might not use it as often because it is seemingly "less practical" than normal lenses. But this has become my favourite lens to bring everywhere! You can really be creative with this lens and take some specacular pictures.

Pentax build quality; quick AF; light

Can't attach filter to protect lens (like most fisheye lens

I have the Pentax 12-24 lens already, but found that I really wanted something that was going to offer another perspective. The DA 10-17mm f/3.5-4.5 ED(IF) by Pentax offers a fish-eye look at 10mm while having minimal distortion by 17mm.

fisheye at 10mm but pretty straight at 17mm

hard to add polarizing filter

This lens is one of hardest to use because of image distortion is very serious. However, once you have used, you can't stop because it makes the object emphasised. So Great!!!

The lens gives a viewing angle of 1800 at 10mm and 1000 at 17mm and being a DA format lens this equates to a 15mm-25.5mm full-frame equivalent.

"I would like to start by stating am a very amateur photographer. I have read many reviews about extra wide vs. fisheye lenses. I do not have an extra wide angle lens and so I relied on online reviews to make my choice.