SIGMA 8-16mm F4.5-5.6 DC HSM

I just saw that Sigma have released their 8-16mm F4.5-5.6 DC HSM for crop sensor. Wow, that's WIDE for a non fisheye! Will interesting to see how it goes in the water.

I would assume that such a wide lens would have even more problems with soft corners though?

Ryan.

That's a wide lens. 4.5 to 5.6 makes is a somewhat slow lens.

If it's anything like the 12-24 on FF, the corners will be soft until f11, and best at f16... by which time it'll be softened by diffraction. This is all tested on 16 and 21mp cameras.

It is for APS size cameras. These cameras crop out the soft edges. The reason why some prefer APS size cameras to full frame for wide angle.

Still I would be suspicious of soft corners due to the slow maximum aperture of this lens.

If it's anything like the 12-24 on FF, the corners will be soft until f11, and best at f16... by which time it'll be softened by diffraction. This is all tested on 16 and 21mp cameras.

Let's not speculate about soft corners until someone actually takes the lens underwater.

The built-in hood could be a problem for those of us with smaller domes and could cause unwanted reflections from inside larger domes.

It also looks like a "Phat" lens, remember the problems with the Nikon 105 VR and port diameters!

The minimum focus of 0.46m makes me think a diopter might be needed with a dome port.

Since the Sigma 12-24 has a minimum focus distance of 0.28m, this sounds like a different optical formula and not just the 12-24 scaled down for APS sensors.

Edit to add: it looks like I made a mistake, the 8-16 actually has a minimum focus distance of 24cm. Now that I look, I can't actually find where I got the 46cm number, although I swear I didn't make it up!

The minimum focus of 0.46m makes me think a diopter might be needed with a dome port.

According to the stats on dpreview (which I'm not saying is correct):

Closest focus distance 24cm (9.4in)

Does anyone know how much this lens will cost?

does anyone know the release date? can not find it anywhere.....