Sigma 18-35mm F1.8 Coming for Pentax!

tzrenz0 · 08-22-2013, 06:33 AM

Originally posted by dadipentak

Good--because I'm broker than I was when I pre-ordered.

I got the standard "Backorder Status" email from B&H a couple of days ago.

haha.

I don't have a lot of wides so I am really longing for this one. Or should I buy a 15 while waiting?

VoiceOfReason · 08-22-2013, 07:26 AM

If you want REALLY wide the 8-16 will get the job done. It's fun too!

**Digitalis** · 08-22-2013, 06:54 PM

Originally posted by VoiceOfReason

If you want REALLY wide the 8-16 will get the job done. It's fun too!

It certainly is fun, but the Sigma 8-16mm f/4.5-5.6 ASPH isn't the brightest bulb* in the chandelier - there isn't really any other option other than the sigma 18-35mm f/1.8 especially if you want an 18mm f/1.8 lens.

*speaking of bulbs - the inability of this lens to use filters is also a bit of a turn off.

Edgar_in_Indy · 08-22-2013, 08:17 PM

Originally posted by Digitalis

*speaking of bulbs - the inability of this lens to use filters is also a bit of a turn off.

I've never used a filter. Am I missing out on something?

**StigVidar** · 08-22-2013, 09:55 PM

Originally posted by Edgar_in_Indy

I've never used a filter. Am I missing out on something?

No. But some do like to use a graduated ND filter on lenses like this. But there are more than one road to Rome......

Barry Pearson · 08-23-2013, 01:39 AM

Originally posted by Edgar_in_Indy

I've never used a filter. Am I missing out on something?

One filter that I hate to be without for any lens is a polarising filter; (for dSLR, that means circular polarising filter). It can't be simulated in Photoshop.

But - it can be tricky with very wide-angle lenses, because the polarisation of the light varies so much over the field of view. I can understand why someone would not think it worth it.

wed7 · 08-23-2013, 02:58 AM

Can't we use square filters on 8-16mm instead?

**Digitalis** · 08-23-2013, 03:04 AM

Originally posted by wed7

Can't we use square filters on 8-16mm instead?

Yes - but they need to be BIG filters, and they need a specialized filter holder to deal with the built-in lens hood.The sigma 18-35mm f/1.8 shouldn't have any issue with regular or square filter systems.

VoiceOfReason · 08-23-2013, 04:35 AM

The Tamron 10-24 and Sigma 10-20 should take filters.

tzrenz0 · 08-25-2013, 06:40 PM

Got a call this morning from DigiDirect, I got excited, thought they're going to ship today, it will be here in 1 and half month from now. Mehhhh. Thought it was a good news turned out it was just a "hang in there" kind of call. I hope it gets to me before I go on a holiday. Crossing my fingers.

Sandy Hancock · 08-25-2013, 07:15 PM

I rang C.R. Kennedy a couple of days ago to enquire about availability of the K-mount version in Australia. I was told not to expect it before December.

**Digitalis** · 08-27-2013, 02:06 AM - **1 Like**

Having handled a copy of this lens, which was owned by a student of mine I can say I'm impressed with the build quality of this lens, however this lens is twice the size of the FA31mm f/1.8 - which is one of the larger sub 50mm lenses pentax has ever made.

Since I don't own a current APS-C format Canon camera my impressions are on the 7D my student was using: The lens is certainly heavy, it balances rather well on a Canon DSLR - Pentax cameras tend to be a bit smaller in certain places and I can sense this may be a bit problematic with current pentax ergonomics. Focusing on this lens can be difficult* for a camera to nail (even for a 7D) due to the limited depth of field. I had to assist my student in calibrating the AF properly (slight front focus issue) and I also suspect that this lens has a bit of residual focus shift as it is stopped down. Sadly, I didn't get a chance to do my usual dedicated tests for optical characteristics on my optics testing bench ( I would have loved the opportunity to do so though).

*let me clarify - In my mind there are two aspects to accurate AF - repeatability and accuracy, the AF repeatability was a bit of an issue. The 7D was able to lock focus, even when I turned the modelling lights down. However there were sometimes marked differences in exactly where the plane of focus was when compared to the preceding image, even though the same point of focus was used on a static subject. Canon cameras do have greater accuracy with lenses with apertures greater than f/2.8 - but as always repeatability is going to be an issue.

Edgar_in_Indy · 08-27-2013, 08:20 AM

Originally posted by Digitalis

*let me clarify - In my mind there are two aspects to accurate AF - repeatability and accuracy, the AF repeatability was a bit of an issue. The 7D was able to lock focus, even when I turned the modelling lights down. However there were sometimes marked differences in exactly where the plane of focus was when compared to the preceding image, even though the same point of focus was used on a static subject.

Interesting observation, as I don't recall reading a review where they complained about focus accuracy (not that I've read them all), but I seem to remember reading at least a few where they praised the lens for its accuracy and consistency. Too bad you weren't able to spend more time with it, especially in the field.

**K6-III** · 08-27-2013, 10:42 AM

At least with Canon and Nikon versions of the lens the USB dock is available to tweak front/back focus at various focal lengths. Who knows when the Pentax version of the Sigma dock might even ship?

rawr · 08-27-2013, 03:17 PM

Originally posted by Digitalis

this lens is twice the size of the FA31mm f/1.8

Indeed, it's a big mofo of a lens.

These photos are from the DCWatch photo review of the lens on a Sigma body:

08-27-2013, 02:06 AM - 1 Like	#387
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Having handled a copy of this lens, which was owned by a student of mine I can say I'm impressed with the build quality of this lens, however this lens is twice the size of the FA31mm f/1.8 - which is one of the larger sub 50mm lenses pentax has ever made. Since I don't own a current APS-C format Canon camera my impressions are on the 7D my student was using: The lens is certainly heavy, it balances rather well on a Canon DSLR - Pentax cameras tend to be a bit smaller in certain places and I can sense this may be a bit problematic with current pentax ergonomics. Focusing on this lens can be difficult* for a camera to nail (even for a 7D) due to the limited depth of field. I had to assist my student in calibrating the AF properly (slight front focus issue) and I also suspect that this lens has a bit of residual focus shift as it is stopped down. Sadly, I didn't get a chance to do my usual dedicated tests for optical characteristics on my optics testing bench ( I would have loved the opportunity to do so though). let me clarify - In my mind there are two aspects to accurate AF - repeatability* and accuracy, the AF repeatability was a bit of an issue. The 7D was able to lock focus, even when I turned the modelling lights down. However there were sometimes marked differences in exactly where the plane of focus was when compared to the preceding image, even though the same point of focus was used on a static subject. Canon cameras do have greater accuracy with lenses with apertures greater than f/2.8 - but as always repeatability is going to be an issue. Last edited by Digitalis; 08-27-2013 at 02:20 AM.

08-27-2013, 03:17 PM	#390
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Originally posted by Digitalis this lens is twice the size of the FA31mm f/1.8 Indeed, it's a big mofo of a lens. These photos are from the DCWatch photo review of the lens on a Sigma body: Attached Images

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08-22-2013, 06:33 AM	#376
tzrenz0 Veteran Member Join Date: Oct 2012 Location: Gold Coast Photos: Albums Posts: 324	Originally posted by dadipentak Good--because I'm broker than I was when I pre-ordered. I got the standard "Backorder Status" email from B&H a couple of days ago. haha. I don't have a lot of wides so I am really longing for this one. Or should I buy a 15 while waiting?

08-22-2013, 07:26 AM	#377
VoiceOfReason Site Supporter Join Date: Jun 2010 Location: Mishawaka IN area Photos: Albums Posts: 6,124	If you want REALLY wide the 8-16 will get the job done. It's fun too!

08-22-2013, 06:54 PM	#378
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Originally posted by VoiceOfReason If you want REALLY wide the 8-16 will get the job done. It's fun too! It certainly is fun, but the Sigma 8-16mm f/4.5-5.6 ASPH isn't the brightest bulb* in the chandelier - there isn't really any other option other than the sigma 18-35mm f/1.8 especially if you want an 18mm f/1.8 lens. *speaking of bulbs - the inability of this lens to use filters is also a bit of a turn off.

08-22-2013, 08:17 PM	#379
Edgar_in_Indy Veteran Member Join Date: May 2010 Location: Indiana, USA Photos: Gallery Posts: 2,685	Originally posted by Digitalis *speaking of bulbs - the inability of this lens to use filters is also a bit of a turn off. I've never used a filter. Am I missing out on something?

08-22-2013, 09:55 PM	#380
StigVidar Site Supporter Join Date: Nov 2006 Location: Norway Photos: Gallery \| Albums Posts: 705	Originally posted by Edgar_in_Indy I've never used a filter. Am I missing out on something? No. But some do like to use a graduated ND filter on lenses like this. But there are more than one road to Rome......

08-23-2013, 01:39 AM	#381
Barry Pearson Veteran Member Join Date: Jul 2013 Location: Stockport Posts: 964	Originally posted by Edgar_in_Indy I've never used a filter. Am I missing out on something? One filter that I hate to be without for any lens is a polarising filter; (for dSLR, that means circular polarising filter). It can't be simulated in Photoshop. But - it can be tricky with very wide-angle lenses, because the polarisation of the light varies so much over the field of view. I can understand why someone would not think it worth it.

08-23-2013, 02:58 AM	#382
wed7 Pentaxian Join Date: Mar 2010 Location: Manila, Philippines Posts: 1,421	Can't we use square filters on 8-16mm instead?

08-23-2013, 03:04 AM	#383
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Originally posted by wed7 Can't we use square filters on 8-16mm instead? Yes - but they need to be BIG filters, and they need a specialized filter holder to deal with the built-in lens hood.The sigma 18-35mm f/1.8 shouldn't have any issue with regular or square filter systems.

08-23-2013, 04:35 AM	#384
VoiceOfReason Site Supporter Join Date: Jun 2010 Location: Mishawaka IN area Photos: Albums Posts: 6,124	The Tamron 10-24 and Sigma 10-20 should take filters.

08-25-2013, 06:40 PM	#385
tzrenz0 Veteran Member Join Date: Oct 2012 Location: Gold Coast Photos: Albums Posts: 324	Got a call this morning from DigiDirect, I got excited, thought they're going to ship today, it will be here in 1 and half month from now. Mehhhh. Thought it was a good news turned out it was just a "hang in there" kind of call. I hope it gets to me before I go on a holiday. Crossing my fingers.

08-25-2013, 07:15 PM	#386
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,272	I rang C.R. Kennedy a couple of days ago to enquire about availability of the K-mount version in Australia. I was told not to expect it before December.

08-27-2013, 08:20 AM	#388
Edgar_in_Indy Veteran Member Join Date: May 2010 Location: Indiana, USA Photos: Gallery Posts: 2,685	Originally posted by Digitalis let me clarify - In my mind there are two aspects to accurate AF - repeatability* and accuracy, the AF repeatability was a bit of an issue. The 7D was able to lock focus, even when I turned the modelling lights down. However there were sometimes marked differences in exactly where the plane of focus was when compared to the preceding image, even though the same point of focus was used on a static subject. Interesting observation, as I don't recall reading a review where they complained about focus accuracy (not that I've read them all), but I seem to remember reading at least a few where they praised the lens for its accuracy and consistency. Too bad you weren't able to spend more time with it, especially in the field.

08-27-2013, 10:42 AM	#389
K6-III Site Supporter Join Date: Apr 2010 Location: Montreal Posts: 222	At least with Canon and Nikon versions of the lens the USB dock is available to tweak front/back focus at various focal lengths. Who knows when the Pentax version of the Sigma dock might even ship?