[JHD]

15mm on APS-C is NOT ultra wide.

Unlike a long lens, every mm at the short end makes a big difference. Try mounting a 10-20mm lens on a camera and set it a 15mm before looking through the VF. Then pull back to 10mm. If you have no idea how much 5mm can make (at the short) the difference is enough for most peoples jaw to hit the floor. Now if you think that is wide, do the same thing with the 8-16mm lens. Pull back from 10mm to 8mm.

Anyone contemplating an ultra wide lens needs to know just how vast each mm is before choosing a lens.

[wlachan]

Depends on how old you are I guess. 24mm was ultra wide decades ago, then came 20mm, 18mm, 15mm, 8mm, 6mm (a lens that sees behind you, okay the last 2 are fisheyes). DA15 is like 22.5mm on FF, that's ultra wide to some, or me. My comfortable wide stops at 24mm, which is 16mm for 1.5x crop. Now if Pentax made a DA16/2 ED AL w/o SDM, I am willing to drop 1k for it.

[RioRico]

If I could just get the hoodlet off my DA10-17 without wrecking the lens, it would be a frame-filler on my FF film cams, with FOV equivalent to 6.66mm on APS-C. Seeing behind me, indeed! The 10-17 FE is what drove me to Pentax in the first place. Yes, it is WIDE! I more recently got a Tammy 10-24 and it's nice, but it doesn't really seem WIDE, not after using the 10-17.

Back in film days, it was easier. Just get a Widelux or similar pano camera, wind it up and tripod it, punch the button, and watch the lens swing around its 180 or 270 degree arc. Or, even simpler, the old oatmeal carton pinhole pano cam. Digital electronics has taken the fun out of wide shooting.

[CWyatt]

I would agree with this. If you are using a DSLR you should not be afraid of larger lenses or zooms.

This is a big generalisation and simply doesn't make sense for some shooters. Part of the reason I use Pentax is the comparatively compact camera bodies. I don't want to go out shooting street with a large lens; it simply isn't the best tool for my work.

[cmohr]

Another very important thing with the Ultrawide, is that they allow you to be close to subject and still be able to get everything in frame. Really with an Ultrawide, the best result is achieved up close, unless you are simply shooting an open landscape specific features are lost with an Ultrawide because they are so small. But, in confined spaces, like streets and buildings in small European towns and villages, you just cant get back far enough to get everything you want in frame, there, the Ultrawide shines, you can have the subject prominate in the shot, yet still get the whole building in one frame. Well, thats the way I use mine.

[crf529]

Does anyone have comparison shots between 8mm and 10mm on a Pentax APS-C to see the FoV difference? Or a link to a website with the same thing? I've been looking for a while but havn't come across a useable set of comparison images to decide whether the 10-20mm will satisfy me, or if the 8-16mm justifies the lack of filter compatibility. I'd love to see some images as I have no access to either lens except for when I purchase off the net.

[cmohr]

I have both so I'll see if I can take a few in the next day or so.

[crf529]

I have both so I'll see if I can take a few in the next day or so.

Thanks very much, that would be fantastic!

[Class A]

Does anyone have comparison shots between 8mm and 10mm on a Pentax APS-C to see the FoV difference?

It only goes down to 10mm but you could try the Tamron focal length comparison tool. Not sure if the sample images are that useful. As cmohr wrote, ultra-wides shine when they exaggerate angles in close proximity. I think the Tamron tool doesn't quite manage to show all the impact a change from say, 14 to 10mm can have.

Have you seen the Sigma 8-16mm and Sigma 10-20mm Club threads? Not quite as good as direct comparisons but useful to get an impression what you can do with these focal lengths.

[cmohr]

Sorry Not very exciting photos, work has been a bit nuts.

I set up the tripod and locked the camera on for the three shots. Each was taken at the widest angle each was capible of, I did not move the camera angle at all between shots. I was about 5-6 meters from the tree, the tree itself would be around 8-9 meters high.

1st - Sigma 12-24 set at 12
2nd - Sigma 10-20 set 10
3rd - Sigma 8-16 set at 8

[crf529]

Thanks heaps for that cmohr! That's exactly the sorta comparison I needed.

The 8-16 is WIDE! Man, I was hoping the difference wouldn't have been that great, but it's quite substantial. Guess i'm no longer set on a 10-20, with some consideration needing to be given the 8-16 now....if only there was a filter solution for it...

[cmohr]

The lens cap is a two piece cap. The whole thing pulls off to reveal the inbuilt steel petal hood, but, if you only remove the pinch cap and leave the sleeve in place you can screw a filter on the front, not sure how much you loose from the 8mm end. Unfortunately it has no gel draw at the rear like the 8mm fisheye does.


Remember, with great wideness, comes great responsibility. lol..

[JHD]

Just imagine what that tree would look like at 15mm. And some people say the DA15 is an UWA!

[DanielT74]

8mm is not a FL that one is likely to need very often at all! What do you plan to use it for?

I find I very rarely need 10-12mm.

I was also not sure which UWA to get so I got all of them, just about. And guess what they are all pretty good.

I guess DA12-14 is probably the best bet overall. Samyang is the sharpest but the distortion is annoying sometimes and needs correction (in PTlens), Sigma 12-24mm probably has the least distortion is not the sharpest but OK and meters very funny on my K20D so I have to watch for that. The old K 15/3.5 is probably the best IQ you can get in pentax ultrawide and meters well in the Av mode but I am very scared to take it out in bright conditions - I suspect it will flare terribly (but haven't tried yet - it's been very overcast).

Sigma 10-20/4-5.6 is a good compromise in terms of IQ, size and price. Tamron is not bad at all if you don't worry about your corners being a bit soft.

Da15 is nice enough, small and snazzy, but the Da 12-24 is probably better is all respects except possibly the distortion.

Been trying the Leica 19/2.8 ver. 1 and it is sharp as hell in the centre and has the typical Leica colours. Will probably have to stop it down to f7.1 or so to get very sharp corners.

Want the ultimate UWA lens? They say that Leica 15/2.8 is perfect (at 7k)!

[selar]

Just imagine what that tree would look like at 15mm

Depends on which tree you are looking at. For example the tree in the far right wouldn't look like it was about to fall down on the DA15.

I like my wide angles rectilinear, thank you kindly.