[Biro]

Okay, I've read all the reviews for the Pentax DA 12-24mm f/4 and the Sigma 10-20mm f/4-5.6. And I've read strings about both lenses on this forum. Both lenses are quite good but of course have different strengths and weaknesses. I have seen beautiful images from both.

To sum up, most Pentaxians say if you have the money, the overall IQ of the Pentax 12-24 is the best while the Sigma is still a great alternative for a lot less money. The truth is, the price and 10mm wide end attract me to the Sigma while I like everything else about the Pentax. In other words: Is it worth $700 for the Pentax to gain an extra 4mm over my DA*16-50 and DA 16-45?

I think it boils down to this for me: How much of a difference does that extra 2mm on the Sigma make in the real world? We know that 2mm makes a lot more difference in the 10-12mm range than it does at 100mm - or even 50mm. But can the disadvantage of the Pentax with this particular feature be overcome by a step or two backward in that range? Or do owners of UWA lenses find that typical subjects (such as landscapes) usually offer no such latitude? And in terms of distortion, is the Sigma more or less equal with the Pentax if you take the lens from 10mm to 12mm?

I've been wrestling with this lens choice for a while and I think I want to get on with it very soon. Thanks in advance for any input.

[AndrewG NY]

One thought. The ultra-wide zooms like DA12-24 are virtually distortion-free at 15-16mm while the wide end of the standard zoom will be at its worst.

If you've seen sample images from 10 & 12mm you should know that they are very different from 16mm. How important 10 vs. 12 is to you is another question. I find with the 12-24 even reaching to 24mm that I still end up switching to other lenses pretty often. Another consideration is whether you have any interest in the 10-17 fisheye zoom--at 17mm it basically starts where the other ultra-wide zooms leave off (effective angle of view at 17mm is about the same as the 12mm end of the DA12-24) but with more distortion.

[Doanh]

I have both. I succumbed to LBA and bought the Sigma 10-20 brand new but then later found a used Pentax 12-24 at reasonable price. They are both so wide that I don't really see the 2mm difference. Pentax is better in term of even sharpness, distortion and color. BTW, don't forget Pentax DA 14mm f2.8.

Peter

[Pentaxor]

unless you are taking landscape shots which are shoot at a considerable long distance, the 2mm difference can increase exponentially. the effects don't look that much if you are shooting at close-up shots around MFD but as you focus to infinity or long range, the difference between the two lenses show. the DA12-24 has better IQ than the Sigma 10-20 so think this over if this is important for you. the Sigma isn't bad though but is enough to get the job done. as far as focal length difference is concerned, this depends on the photographers need. you might prioritize the wider end of the zoom or you might want to have the longer end of the zoom. personally, I want my zoom to have the 24mm focal length when I'm on a 1 camera and one lens setup for walkarounds, since I usually tend to shoot closer shots with a longer focal length for magnification or closer view of the subject and most of the times, I find that most of my shots are at 24mm due to my use and situational preference. the 10mm focal length is more useful to those who liked and want a convenience of a wider perspective lens or to those who shot with one more often.

anyway, if I were someone who prefer or uses a wider fov most of the time, the Sigma 8-16 would be the best alternative. judging from the images shown, it looks to be as good as the DA12-24 or a even bit better.

[elho_cid]

I find it quite difficult to find good composition of an image on ultra wide FOV. I prefer to use the UW to stress the extreme perspective. For this the DA14 s ideal, allowing to focus as close as 1 inch from the front element.

[Big G]

I had the same dilemma on my K20D and ending buying the Sigma 10-20mm for the following reasons:

- Cost. The DA 12-24 was over twice the price at the time.
- Distortion. Whilst the DA 12-24 is reasonably well controlled at 12mm, the Sigma is better corrected for barrel distortion at 10mm than the Pentax is as 12mm. The Sigma is pretty distortion free except for the extreme corners of the frame.
- Reputation. The Sigma was well regarded across Pentax / Canikon.

However, based on Photozone's resolution tests, the DA 12-24 shows much better corner performance at the wider apertures than the Sigma - this may or may not be important to you.

Would you notice a 2mm difference? probably not; I often shoot my Sigma 10-20mm at 12mm anyway because my polarising filter can be visible in the extreme corners at anything less than 12mm.

[pop4]

Here's a chart I did a while back with my Sigma 10-20mm. It's a bit rough and there's no 12mm, but I think it provides a rough idea of what you're after, and also notice the BIG difference between 16mm, and 10mm.


Note that the image only compares FOV, and does not take into account the changes in perspective and the 'compression' effect of longer lenses.

[Biro]

Wow, pop4... that's pretty impressive and quite helpful. Distortion doesn't seem that bad at the edges. I imagine if people were located where the swing set and trees are it might be more obvious. I apprecicate all the feedback. Both lenses continue to appeal to me at different levels but all of this helps. Any further input is still quite welcome.

[jeffshaddix]

How about the new Sigma 8-16mm? It's optically better than the 10-20, and has HSM to boot!

[typical8o8]

How about the new Sigma 8-16mm? It's optically better than the 10-20, and has HSM to boot!

i have one currently en route and am just chomping at the bit to play with it.

not to threadjack, here's a post showing the difference in angle of view between 8mm and 10mm. it doesn't answer the OP's question specifically but gives some idea of a 2mm difference in UWA.

Unique Photo: Lens Review: Sigma 8-16mm f/4.5-5.6 DC HSM

[Biro]

Thanks for the link. Unique Photo is in New Jersey, my home state, BTW. You're not threadjacking at all. It's funny... I'd never seriously considered the Sigma 8-16mm. I wonder how many owners of the Pentax 12-24 would have gone for the Sigma 8-16 if it were available at the time they made their purchase? I wonder how useful it is hand held. But it is an interesting proposition.

[Jools]

I have taken some interest on this thread because I am in the market for a UWA.
At the moment, I got my eyes set on a 10-17mm distortion and all.

[Pentaxor]

Thanks for the link. Unique Photo is in New Jersey, my home state, BTW. You're not threadjacking at all. It's funny... I'd never seriously considered the Sigma 8-16mm. I wonder how many owners of the Pentax 12-24 would have gone for the Sigma 8-16 if it were available at the time they made their purchase? I wonder how useful it is hand held. But it is an interesting proposition.

I may have done so and would had gotten myself an FA20-35 as a secondary zoom wide lens. but with my current line-up, Im pretty much covered those secondary wide focal lengths. will I be missing the 4mm difference between the 12 and 8mm? probably not, but it would had been a great capability and luxury for a much wider perspective. maybe for ultra-tight situations involving corridor shots which requires a wider view.

[Big G]

I have taken some interest on this thread because I am in the market for a UWA.
At the moment, I got my eyes set on a 10-17mm distortion and all.

I have the Sigma and the Pentax fish-eye, in my opinion the fish-eye is a niche lens, it only works well where fish eye adds something to the shot (architecture, urban etc.). You also can't use filters with the Pentax 10-17mm which will scunner a lot of landscape photographs; the Sigma is definitely better suited here. That's not to say you can't use it for landscapes (I have a few taken), but I really don't think the fish eye distortion suits it.

It's all down to personal opinion, but worth listening to a guy that owns and shoots both lenses .

[Lowell Goudge]

Let's look at this another way

First of all I have the sigma 10-20 and I use this lens a lot. In fact on average I use it for 20% of all my shots, and 60% of all shots with this lens are at 10mm I would mis the extra FOV now that I have used it if it were taken away

My first "ultra wide" was the FA-J 18-35 on film. This is equivalent to the 12-24 on a DSLR so I had experience at that focal length and the additional width is greatly appreciated

There is a review of all current ultra-wides in a UK magazine and pentax is rated very poorly compared not only to the sigma but to canon and nikon also. The minimum focal length is considered along with Sony's offering as unimpressive. In fact the conclusion of that magazine is that compared to all other lenses in this range it is over priced for what you get