12-24mm on full frame K7.....

Hello,

Just got a big job doing interiors so I'm going to treat myself to a new lens, was looking at sigma 10-20mm but read that it would vignette images on full frame sensor.... Have K10, K20 and K7 and want to use the K7 for it's Full frame-ness.

Just wondering if the 12-24mm is designed for full frame images, as I need good lean images with nooooo dark edges.

Many thanks,

K

Mmmmm...the K7 isn't full frame.

I think you are confusing some of the industries confusing terms....
100% viewfinder view is not the same thing as Full Frame... Full Frame is a sensor the same size (24x36mm) as a frame of 35 mm film.
The k7 has an aps sized sensor...
you'll get the same "cropped" feild of view on the k7 as you would on the k20, only you'll have a more accurate view (in the viewfinder) of what is in that frame with the k7...

Ahh, I think Don may have sussed the confusion. Having said that, the 12 -24 is a very nice lens and more than capable of doing what you want on the K7 . ( or the K20 for that matter)

The DA 12 - 24 would be ideal for your new assignment.

Occasionally they appear for sale on the forum.

Ahhh I see.... okay indeed I am confusing full frame viewage with the sensor and have done so because I read about the sigma 10-20mm vignetting when on a full framer, didn't realise there was a full frame sensor and FF viewfinder, and that they were separate things... I don't really know my onions when it comes to sensors so thank you kindly for putting me straight. So I guess with a full frame sensor you don't get the crop factor that changes the effective focal length of the lens? Just getting my head round all of that stuff.... haven't been digi very long, tis alot different and a friking minefield.... I mourn my 6x6.

So that sorted, I have the choice of 2 again..... which lens sigma 10-20mm or Pentax 12-24mm.....???? hmmmm

Thanks for your help guys, I hope pentax pay you well....

Yes you wouldn't have to do that since the size of full-frame sensor equals that of 35mm film, but that isn't the same as it is on 6x6 film though.

Of the two lenses the 12-24 is the best one but also a lot more expensive in the UK. If you really want the Pentax I would advice you to shop abroad or better yet contact Amin (aminstar) a member of this forum.
He bought some Samsung versions of the Pentax lens very cheaply some months ago and might still have some left.

I have a Sigma 10-20 and I'm happy with it but I think the 12-24 supporters will say it suffers from more distortion and thank the lord it does because that's one its characteristics that I like.

I suspect that the 12-24 will suit your needs better.

If you are doing interiors I'd just like to say that probably teh best HDR shots I have seen were done for interiors where all parts of the room were well exposed and the view from the windows was as well. I have sadly lost the link but it was a clever Canadian lady called Sheena who managed it.

Mike

All of these images were shot using a K20D and the DA 12-24mm. With careful camera positioning you'll get good coverage and very little perspective distortion (converging verticals). OK, I wasn't so careful in some of them.

All interior shots used an AF540FGZ without any diffuser but aimed at the white ceiling for plenty of diffused light.

Shots through the windows would have benefited from HDR treatment but it wasn't necessary for my purpose.

Lots of fans of 12-24mm here, I would certainly buy it again if I had to.

The DA12-24 gets my vote too - I'd buy it again without hesitation

(and mine is primarily used for interior shots where it excels)

Hold on before this becomes one sided

My name's Mike and I'd buy a Sigma 10-20 again if I had to

The Pentax lens is good but so is the Sigma.

The original Sigma 10-20 (the DC F4-5.6) shows quite pronounced barrel distortion at 10mm (which is almost gone by 12 mm). So straight lines at the edges are not straight at the extreme wide end of the range.

By any measure, especially for anything architectural, inside or out, this can't be a good thing.

Presumably, Mike, the 'distortion' you like is the way when you're already close, anything even slightly closer looks so much bigger, so you get the apparent enlargement of objects at the edges when the subject plane is close to the focal plane, and extreme converging verticals when the camera isn't horizontal.

These can be interesting effects, but it's not the same as barreling. By all accounts (though I have no direct experience of it), the 12-24 is much better in this regard.

All that aside, I've had the 10-20 for quite a while now, and in value-for-money terms, it's excellent.

The barreling can be removed in software easily enough, too, and it has less CA (which can also be removed in software) from what I've heard than the Pentax 12-24.

As for vignetting, I have a thin UV filter (Hoya Pro1 digital) on mine, and even with that at 10mm on the K10D, any vignetting is pretty minor. It's often hard to get lighting that is so perfectly even that I can be sure it's vignetting rather than anything else.

I think it comes down to budget, whether you have a need for 10mm as opposed to 12, and preference for colour rendition, since all the other issues can be fixed in software. I certainly prefer the 'look' from Pentax lenses in general when I've had enough information to form a view, but it's not enough to justify the cost of the Pentax 12-24 for me.

Have gone 12-24mm purely as I got it for a super price from Amin. I don't doubt that the sigma 10-20 though.... I bought the Sigma 17-70mm for weddings at the begining of the year, as pentax didn't offer one and it's a corker.

Thank you for all your help peeps, it's muchly appreciated...

K x

Wise decision re. the 12-24 IMHO. Re. the 17-70, Pentax do offer one actually. Very nice it is too, though now rather overpriced in comparison to the Sigma.