[klh]

I'm looking forward to a trip to Niagara Falls this summer, and wanting to get an UltraWide lens for the scenery. I can also see using it for cityscapes and inside churches when I visit Europe. I don't see myself using it as often as my 28-75 and 70-200 lenses.

I can't seem to narrow down my choices between Tamron 10-24/3.5, Sigma 10-20/4, DA14/2.8, DA15/4, Vivitar 13/2.8, or Samyang 14/2.8, so help me with a few questions.

1) How important would a fast aperture of f/2.8 be? Most likely I will be on a tripod when I use this and can use slower shutter speeds anyway.

2) How often would one be frustrated with 13-15mm not being wide enough?'

3) How do you compare the weight/portability of the DA15?

4) Is manual focus all that difficult with these?

5) Does the rule that image quality of a prime is superior apply to this focal range?

In the end it may just come down to the best deal I can find at the time, but I'd like to narrow the field a bit.

[paperbag846]

1) How important would a fast aperture of f/2.8 be? Most likely I will be on a tripod when I use this and can use slower shutter speeds anyway.

Not very. Shutter speeds at the wide end matter little, low DOF stuff is not the primary use of these lenses. They have *some* utility, but not as much as a longer fast prime would.

4) Is manual focus all that difficult with these?

Yes... it's just not very easy to see.

AF is the way to go.

5) Does the rule that image quality of a prime is superior apply to this focal range?

Not really. Pentax 14 / 15 / 12-24 are all similar in IQ. Size / utility of each is very different.

2) How often would one be frustrated with 13-15mm not being wide enough?'

Incredibly subjective. I would say I often find it too wide, but others would say theycan't live without their sigma 10-20.

3) How do you compare the weight/portability of the DA15?

This is the best reason to get the DA 15... size. Yes it looks good but so do the others... this lens is strong in compactness.

[twitch]

I can't seem to narrow down my choices between Tamron 10-24/3.5, Sigma 10-20/4, DA14/2.8, DA15/4, Vivitar 13/2.8, or Samyang 14/2.8, so help me with a few questions.

1) How important would a fast aperture of f/2.8 be? Most likely I will be on a tripod when I use this and can use slower shutter speeds anyway.

2) How often would one be frustrated with 13-15mm not being wide enough?'

3) How do you compare the weight/portability of the DA15?

4) Is manual focus all that difficult with these?

5) Does the rule that image quality of a prime is superior apply to this focal range?

In the end it may just come down to the best deal I can find at the time, but I'd like to narrow the field a bit.

1. not very
2. I'm finding 12 nice to have, but it's pretty rare 15mm isn't wide enough for me
3. The 15 is an absolute joy to use compared to my 12-24, as a result I use my 15 far more, in fact it's probably my most used lens.
4. UWAs are easy use hyperfocal, actually the DA15 is as it has markings but the 12-24 doesn't, for that I just guess
5. No, except perhaps for flare resistance which the DA15 has in spades.

[JHD]

I agree with everything paperbag said, however if the size and weight on a short to normal range lens is an issue, then you're need to supplement your kit with a smaller camera. My NEX-5 makes any DSLR (including the K-x) look like a gigantic monster and feel like boat anchor. Even so that wasn't my motivation for supplementing my system with a NEX.

[paperbag846]

if the size and weight on a short to normal range lens is an issue, then you're need to supplement your kit with a smaller camera.

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

After I got over my honeymoon with the DA 40, I realized it was just too compact for the camera. I would be brilliant on an ASPC EVIL, though.

I think the DA 15 is best for A) Adventurers, or B) People who need a wide angles but it's not their most used lens. That way it does not take up too much space in the bag but still makes it out. I mostly shoot on the longer end, and if I had a 12-24, I doubt I would be able to justify bringing it out with me. On the other hand, the 15 almost always sees the bag, even though I don't always end up using it. I'm going to guess most people who use the DA 15 fall into the second category.

If you plan on using wide angles a lot, you will be much better served by some sort of zoom IMHO.

[zoltan1983snapper]

Sigma 8-16

[wjt]

What paperbag and twitch said basically sums it up. The only drawback of the 12-24 is the size. With the K5 era sensors you can easily bump the ISO up for shooting inside churches etc so the difference between f2.8 and f4 is not an issue for travel happy snaps bearing in mind basically all the churches won't allow a tripod to be used, not sure on the monopod though. Landscapes are going to be at higher aperture anyways. The 15ltd is small, I have used one a few times and I will be buying one once BH gets it back in stock (this may be a factor if you want it soon).

[cmohr]

Got admit, UltraWide is a specific term.

On film I originally had a 24mm/2.8 and it was great, but longed for wider, I eventually got the 17-28 Fisheye Zoom and the Sigma 12-24 and they had all the view I could ever want. But then, digital reduced there feild of veiw to ordinary wide angle statis.

I then managed to get a 8mm fisheye, but was delighted with the Sigma 10-20 when I first put it on the camera, but, still, wanting for that ultrawide lens, Till the 8-16 became available. Wow, it has terriffic angle of veiw, creates a wide broad image, incredible perspective. Happy chappy now. It doesnt have a big Fstop, but being so wide it is no problem whatsoever, I can hand hold up to 1 sec on low light conditions and still achieve an acceptable result.

PS - I also put the Pentax 10-17 Fisheye zoom in the camera bag too.

[Ash]

The 12-24 may take up a little more girth space in your camera bag than your Tamron 28-75, but not extra weight. I have found I use 12mm often when I carry this lens with me.

Most of these UWA zooms are rather bulky lenses, but not the DA 15 ltd (quite a unique little lens - I haven't seen anything like it in size, and its IQ is top notch).

[jlstrawman]

The IQ of my Sigma 10-20, f4-5.6, is more than adequate. I have not found f4 to be a limitation in any situation to date.

[klh]

If you are using a DSLR you should not be afraid of larger lenses or zooms.

Ha! Who's afraid?

It's not that I don't want larger lenses, it's just that my travel bag has enough room for my K20D with grip, th 28-75, and couple smaller lenses. I prefer not to take the full backpack when I'm flying to Europe or packed in a minivan with four kids. The DA 15 is attractive since it won't take up much space.

Lots of good thoughts here. Thanks. I've got some thinking to do.

[Class A]

I can't seem to narrow down my choices between Tamron 10-24/3.5, Sigma 10-20/4, DA14/2.8, DA15/4, Vivitar 13/2.8, or Samyang 14/2.8, so help me with a few questions.

There is no Sigma 10-20/4. There is one constant aperture version 10-20/3.5 (has seven aperture blades which allow nice starburst effects, and has HSM) and a variable aperture version 10-20/4-5.6 (which has screw-drive AF, has a bit more complicated distortion at 10mm but less CA overall). Both lenses are very good and popular and I suggest that you look at individual test results to check which one ticks your boxes.

The Tamron 10-24 is generally regarded as being optically not quite as good as the Sigmas.
I personally wouldn't consider the primes unless you had very specific reasons (less weight in the bag, potentially better flare resistance, ...).

You might also want to look at the Sigma 8-16. Those who own it, typically love it.

1) How important would a fast aperture of f/2.8 be?

As others have said: Not very important in general. Ultra wides get a lot in the frame and their bokeh isn't fantastic; one usually uses them stopped down to achieve sufficient DOF for rendering almost everything acceptably sharp.

Most likely I will be on a tripod when I use this and can use slower shutter speeds anyway.

If your subjects don't move, you may also consider doing panoramas with a less wide lens. Potentially much better quality but problematic if things in the frame move.

2) How often would one be frustrated with 13-15mm not being wide enough?'

I understand many opt for a 10-20 rather than a 12-24 because the 2mm at the wide end really matter. The increase in FOV is substantial (unlike a 50mm increase from 300 to 350 which is insignificant in comparison, i.e., less of a tenth). If you like ultra wide, you'll like 10mm or even 8mm. BTW, when comparing FOV figures between lenses, note that Sigma expresses the FOV of their lenses in terms of their (slightly smaller) own Foveon sensor. This means their FOV figures are not as high as they would be if they expressed them in terms of Pentax/Sony APS-C.

4) Is manual focus all that difficult with these?

Contrary to what has been written before, it is a piece of cake. I use my 10-20 in MF all the time. At most f-ratios the DOF is huge so just make sure the nearest object you want to have sharp is in focus (the green, focus confirmation, hexagon helps) and typically the rest will be fine. You can also go a step further and use hyperfocal focusing. With typical apertures, the hyperfocal focusing distance will be really short so many times it can be a matter of "set and forget".
Ultra-wides are the easiest lenses to MF. They seem to be hardest to AF as well, since the AF area covers so much content. I believe that experienced wide-angle shooters avoid AF.

5) Does the rule that image quality of a prime is superior apply to this focal range?

On this forum, I've often read that the Pentax 12-24 is at least as good as the wide-angle Pentax primes. I believe the Sigma 10-20/3.5 is better than the 12-24 in some disciplines and worse in others. Again, worth looking at individual aspects of tests, rather than going for an overall star rating or similar.

[wlachan]

1) Not very for scenery. The classic approach is f8-11 on tripod.
2) If you have tried to cover everything, no lens is ever wide enough. However, being too wide can be boring if not used effectively.
3) It's as small as it gets.
4) Manual focus with super wide is difficult even with 2x viewfinder magnifier. When I thought it was in focus, often it wasn't. No idea how other LV works, but my 40D's LV is off the actual 10MP CCD. At 10x, I can nail the focus with great precision. Something my K-m cannot. However, you will likely to use hyper-focal for scenery.
5) Not anymore imho. My EF-S 10-22 is sharper than my DA14 corner to corner. In fact, I have found the DA14 quite poor for scenery where the sharpness beyond the centre 60% is rather embarrassing even stopped way down. With subject matters like high contrast buildings, they appear sharp. For trees, they are simply blurry. All 3 copies I have come across share this characteristic. Even the DA16-45/4 is much better. No idea what went wrong. I will try a few more times and see. If you don't mind the size, the Sigma and the DA12-24/4 are probably the best for Pentax. The DA is known to have CA though, so it might take some time to remove afterward.

[reeftool]

The majority of my shots with wide angle lenses are stopped down to f/8 or more so for myself, f/2.8 wouldn't be much of an advantage but everybody's needs are different. I can understand the difficulty choosing which lens as I went through it myself. They are all pretty good lenses. I bought the 10-17 because I love fisheyes and the DA 15 for its size and no regrets so far on my choices. I spent days looking at photos throughout the forum from all the wide lenses and there are some stunning shots from all of them. You are really getting down to nit picking comparing IQ so you really have to look at other things. The slight size difference between a 12-24 and 10-20 might make a difference. Do you need the extra reach to 24mm? How about even wider yet with the Sigma 8-16? There are also price differences. The Samyang's are cheaper but manual focus. The DA 12-24 is the most expensive. It's a tough decision... good luck!

[john5100]

Go for the DA12-24. GREAT LENS