Pentax Forums reviews the Sigma Art 18-35mm
Posted 03/11/2014 - 08:50
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Interesting how it gets slated for poor AF performance; but could that not be down to the camera AF sensor not able to work well with such a wide aperture as the DOF is too low? Pentax make the point that some of the sensors can cope with f2.8 for example and so is 1.8 (and 1.4 for the other art lens) too open?
Andy
Posted 03/11/2014 - 15:02
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Don't know really, Andy?
I read somewhere that Pentax use F2 sensors but just rate them as better than 2.8, no idea where though! What strikes me about the review is not really how good the Sigma is, as it's fantastic in all areas except the focus thing, it is a very very bright zoom lens, so it may be affecting the K3 Af? It's how well the 20-40 Ltd did against it and just how bad the DA* 16-50 is? The 16-50mm performance actually came as no suprise to me as I have had two of those previously and decided to bail on that un permanently but the 20-40 has now piqued my interest...
I read somewhere that Pentax use F2 sensors but just rate them as better than 2.8, no idea where though! What strikes me about the review is not really how good the Sigma is, as it's fantastic in all areas except the focus thing, it is a very very bright zoom lens, so it may be affecting the K3 Af? It's how well the 20-40 Ltd did against it and just how bad the DA* 16-50 is? The 16-50mm performance actually came as no suprise to me as I have had two of those previously and decided to bail on that un permanently but the 20-40 has now piqued my interest...
Cheers Jules...
My viewfinder is 576,000,000 pixels.
My other viewfinder is 5.76,000,000.
www.exaggeratedperspectives.com
My viewfinder is 576,000,000 pixels.
My other viewfinder is 5.76,000,000.
www.exaggeratedperspectives.com
Posted 03/11/2014 - 17:40
Link
jules wrote:
Don't know really, Andy?
I read somewhere that Pentax use F2 sensors but just rate them as better than 2.8, no idea where though! ...............
You shouldn't be reading nonsense like that Jules Don't know really, Andy?
I read somewhere that Pentax use F2 sensors but just rate them as better than 2.8, no idea where though! ...............
Have you seen the Digitalis test on the US forum?
Doesn't impress me
--
Half Man... Half Pentax ... Half Cucumber
Pentax K-1 + K-5 and some other stuff
Algi
Pentax K-1 + K-5 and some other stuff
Algi
Posted 03/11/2014 - 17:48
Link
Algernon wrote:
Have you seen the Digitalis test on the US forum?
Doesn't impress me
--
Digitalis??
jules wrote:
Don't know really, Andy?
I read somewhere that Pentax use F2 sensors but just rate them as better than 2.8, no idea where though! ...............
You shouldn't be reading nonsense like that Jules Don't know really, Andy?
I read somewhere that Pentax use F2 sensors but just rate them as better than 2.8, no idea where though! ...............
Have you seen the Digitalis test on the US forum?
Doesn't impress me
--
Andy
Posted 03/11/2014 - 18:09
Link
Algernon wrote:
Have you seen the Digitalis test on the US forum?
Doesn't impress me
--
Nope first review of a lens that I have absolutely no interest in, got a link Algi? It's way to big and fat to make it to my bag
jules wrote:
Don't know really, Andy?
I read somewhere that Pentax use F2 sensors but just rate them as better than 2.8, no idea where though! ...............
You shouldn't be reading nonsense like that Jules Don't know really, Andy?
I read somewhere that Pentax use F2 sensors but just rate them as better than 2.8, no idea where though! ...............
Have you seen the Digitalis test on the US forum?
Doesn't impress me
--
Cheers Jules...
My viewfinder is 576,000,000 pixels.
My other viewfinder is 5.76,000,000.
www.exaggeratedperspectives.com
My viewfinder is 576,000,000 pixels.
My other viewfinder is 5.76,000,000.
www.exaggeratedperspectives.com
Posted 03/11/2014 - 18:30
Link
alfpics wrote:
Interesting how it gets slated for poor AF performance; but could that not be down to the camera AF sensor not able to work well with such a wide aperture as the DOF is too low? Pentax make the point that some of the sensors can cope with f2.8 for example and so is 1.8 (and 1.4 for the other art lens) too open?
I have a Pentax A50 f/1.2 and it's worked great at 1.2 with all the Pentax DSLRs I've owned... K10D, K20D, K-5 ( three of them ) and K-5IIs
Interesting how it gets slated for poor AF performance; but could that not be down to the camera AF sensor not able to work well with such a wide aperture as the DOF is too low? Pentax make the point that some of the sensors can cope with f2.8 for example and so is 1.8 (and 1.4 for the other art lens) too open?
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283
Posted 03/11/2014 - 18:46
Link
Smeggypants wrote:
Well that blows that theory out of the water then!
alfpics wrote:
Interesting how it gets slated for poor AF performance; but could that not be down to the camera AF sensor not able to work well with such a wide aperture as the DOF is too low? Pentax make the point that some of the sensors can cope with f2.8 for example and so is 1.8 (and 1.4 for the other art lens) too open?
I have a Pentax A50 f/1.2 and it's worked great at 1.2 with all the Pentax DSLRs I've owned... K10D, K20D, K-5 ( three of them ) and K-5IIsInteresting how it gets slated for poor AF performance; but could that not be down to the camera AF sensor not able to work well with such a wide aperture as the DOF is too low? Pentax make the point that some of the sensors can cope with f2.8 for example and so is 1.8 (and 1.4 for the other art lens) too open?
Andy
Posted 03/11/2014 - 20:43
Link
Yeah thanks Algi! Both lenses are rubbish!
http://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/270250-pentax-f...
http://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/270250-pentax-f...
Cheers Jules...
My viewfinder is 576,000,000 pixels.
My other viewfinder is 5.76,000,000.
www.exaggeratedperspectives.com
My viewfinder is 576,000,000 pixels.
My other viewfinder is 5.76,000,000.
www.exaggeratedperspectives.com
Posted 03/11/2014 - 21:15
Link
screwdriver222 wrote:
Jeff
It came with a FREE 30 Metre Tape! Quote:
I have a Pentax A50 f/1.2 and it's worked great at 1.2 with all the Pentax DSLRs I've owned... K10D, K20D, K-5 ( three of them ) and K-5IIs
Did it auto focus?I have a Pentax A50 f/1.2 and it's worked great at 1.2 with all the Pentax DSLRs I've owned... K10D, K20D, K-5 ( three of them ) and K-5IIs
Jeff
--
Half Man... Half Pentax ... Half Cucumber
Pentax K-1 + K-5 and some other stuff
Algi
Pentax K-1 + K-5 and some other stuff
Algi
Posted 03/11/2014 - 21:35
Link
The way I read the AF issue, it's also something Nikon and Canon owners have been experiencing, and it seems to only be present with Phase AF.
Hopefully they can fix it via a firmware update, as that issue aside it sounds like a damn fine lens.
Hopefully they can fix it via a firmware update, as that issue aside it sounds like a damn fine lens.
Pentax K-30
DA 18-135 WR, DA 18-55 WR, DA 55-300, FA 35-80
Chinon 50mm 1.7, RMC Tokina 28mm 2.8
32GB Toshiba FlashAir
DA 18-135 WR, DA 18-55 WR, DA 55-300, FA 35-80
Chinon 50mm 1.7, RMC Tokina 28mm 2.8
32GB Toshiba FlashAir
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http://www.pentaxforums.com/reviews/sigma-18-35mm-f18-dc-hsm-art/introduction.ht...
My viewfinder is 576,000,000 pixels.
My other viewfinder is 5.76,000,000.
www.exaggeratedperspectives.com