Wide angle options ?

I currently own the Sigma 17-70 & am delighted with the lens - however I'm looking for a little more at the wide end to complement the 17-70 & was hoping for a few recommendations.

I've already discovered the sigma 10-20 which seems to be well respected, any better alternatives ?

thanks

simon

I haven't tried the Sigma but I am very pleased with the results I get from the Pentax 12-24.

Kim

Either the Sigma 10-20 or Pentax 12-24 would be great options.

In the UK the Sigma is half the price of the Pentax which makes the choice a "no-brainer" for me, however elsewhere (especially in the US) the price differences seem to be considerably slimmer so that could be a big factor.

If both lenses were the same price I'd possibly have went for the Pentax - even though it's not as wide it'd have better re-sale value once Pentax bring out a full-frame body and I can start using my 20-35 F2.8 again. I wouldn't pay much more for the Pentax though.

I haven't tried the Pentax but I am very pleased with the results I get from the Sigma 10-20.

Dan

I've not tried the Sigma but I'd like to put in another vote for the Pentax DA12-24. I really can't fault the IQ and the distortion levels for such a wide lens are astonishingly low (in fact, at 24mm they're pretty much non-existant). If you're in the UK then Mathers of Lancashire seem to have the best price (£489 for the Pentax / £299 for the Sigma): http://www.mathersoflancashire.co.uk/page5.html

Thanks everyone for the information. To be honest the price difference between the Sigma & Pentax makes me lean heavily towards the Sigma.

As I intend using a polariser most of the time could any users give me comments relating to the amount of vignetting I'm likely to find ?

thanks

simon

I use a polariser regularily on my Sigma 10-20 and have not had any problems with vignetting:

I can use my Cokin (actually a Kood) P-size set above 12mm without vignetting, but below that will show the holder. You could always modify the holder by cutting off the front couple of filter slots and that would probably avoid the problem.

If you have a scew in polariser I don't see it being a problem at all (guessing that's what Niblue uses?).

Dan

It is indeed.

I've also used Cokin-P filters with the lens however like you I've also had problems below 12mm or so. I've got a cut-down holder somewhere (that only holds 1 filter) that'll probably work fine down to 10mm but I've yet to try it on this lens.

I have a cut-down P-holder (will hold 1 polariser or 1 filter) - no real problems on the Pentax 12-24. The polariser is the only reason I keep the P system (I can't afford or justify a 105mm circ pol for the Lee kit :shock

A friend of mine has the Canon fit Sigma 10-20mm and has found that the inside circle of the P-holder has to be filed out at the corners - there's a tiny amount of vignetting in the four corners at 10mm otherwise.

Matt

When I use the P filter holder on my Sigma, I don't use an adaptor ring, the holder sits quite nicely in the bayonet mount for the lens hood instead. So the holder sits a bit further back than it would on an adaptor ring, which may well help matters. I'll have to try cutting off the front sections because I only ever use the polariser in it anyway.

Dan

P.S. If the Canon shows vignetting at 10mm, the Pentax would (should) show more, as it's got a slightly larger sensor and therefore a wider field of view with this lens.

Copied from Cokin Website :
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P Wide-Angle Holder (BPW-700) P299:
This extra slim holder helps to eliminate vignetting down to 20mm focal length.
Can hold 1 filter (can be a polarizer) and allows the use of filters with super wide lenses (focal lengths under 20mm) 35mm format.
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Not sure how it'd be at 10mm though... I decided to go with the Z format to cover the wide end, and any larger lenses I (hopefully) may acquire; although I was thinking more about ND Grads than polarizers...

The results of using polarizers at such wide angles sometimes results in uneven polarization, since the FOV has such a wide variance in "angle of reflectance" (I think I just made that term up...) that different parts of the picture receive varying amounts of polarization... I'm sure someone else could explain it better...

I too am wondering if the 10-20 Sigma is going to be ideal for my needs.

Can anyone tell me (by example if possible) what the distortion effects are if photographing say people up close in a street scene, do you get massive distortion of main subject and out to sides?

I ask because I am aware the the 18-55 gives me bendy horizons as it is at 18mm, so will the Sigma 10-20 be a lot worse? Or is it a better lens

Cheers Lilly

There are two types of distortion to think about with wide lenses.

One is an optical fault and that is the inability of a lens to record straight lines as straight lines, especially at the edges. It's usually a result of trying to design a lens for compactness and/or low cost.

The other is the apparent perspective distortion. When you get very close to subjects, as you well might with ultra-wide lenses, the edges and corners will show circles as elongated, so a footbal will look like an American football. This is normal and actiually correct so ther's nothing to be done about it.

I've just received the SMC Pentax-DA 10-17mm which at the wide end exhibits masses of this type of distortion, or at least if it doesn't I'll want a refund!

Used creatively, the "defects" can be turned to advantage.

It's not the sort of shot I take much of, however I've found the Sigma pretty well corrected for a lens that wide. You can get quite unusual results with people just due to perspective though. This one of my wife on the trampoline in our garden being an example: