Ultrawide for the KP

Bertrand3000 · 04-23-2021, 03:00 PM

Originally posted by mikesbike

Not only that, as to16mm from the DA 16-85mm, for subjects having linear features where linear distortion is of concern (buildings, or parts of buildings in the frame, interiors, street light poles, cityscapes, etc.) the distortion will be quite high, where the Sigma 10-20mm f/3.5 will present very low to nil distortion from about 12mm, and has constant aperture design for good low light capability at all its focal lengths.

Now that you mention it, it is a very good point, often overlooked. The Sigma 10-20 is distortion free starting with 14mm if I remember correctly, whereas when I spin around my 16-85 at 16mm in the viewfinder I clearly see the distortion. Time to undust my 10-20.

**mikesbike** · 04-23-2021, 03:36 PM

Good idea! And the super wide angle of 10mm or even 14mm is vey impressive. Just be sure not to confuse wide angle perspective distortion, which can be avoided or improved sometimes just by positioning for a better angle, with linear distortion as it bends a straight line in the middle, even when shot at a perfect dead-on vertical angle. Those test grids for linear distortion tell the story.

AlanM · 04-30-2021, 12:27 AM - **3 Likes**

Thanks for all your advice. I pulled the trigger and got the Pentax 11-18mm yesterday. It has a lot going for it and, after all, it's a Pentax and we all want Pentax to survive and prosper. Now I just need to improve my photographic skills to match the lens.

LittleSkink · 04-30-2021, 01:47 AM

The 11-18 is superb, from what I have seen - much envy here

Not sure how you plan to use it, but having the 10-17 myself I see it much more of a novelty / fun lens (with a bunch of aberration issues to boot) while the 11-18 is a "proper grown up lens" with outstanding capabilities and almost nothing to see in terms of aberrations

bdery · 04-30-2021, 10:52 AM

Originally posted by AlanM

Thanks for all your advice. I pulled the trigger and got the Pentax 11-18mm yesterday. It has a lot going for it and, after all, it's a Pentax and we all want Pentax to survive and prosper.

Congrats on this purchase, it will serve you well.

Bertrand3000 · 04-30-2021, 03:16 PM

Congratulations for your purchase. You cannot go wrong with the 11-18.

**MrNPhoto** · 04-30-2021, 06:17 PM

Agreed, the 11-18 is excellent all around.

**caliscouser** · 04-30-2021, 07:13 PM

Congrats the 11-18 is a no compromise lens unlike the the other options.

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04-23-2021, 03:00 PM	#31
Bertrand3000 Veteran Member Join Date: Feb 2019 Posts: 2,009	Originally posted by mikesbike Not only that, as to16mm from the DA 16-85mm, for subjects having linear features where linear distortion is of concern (buildings, or parts of buildings in the frame, interiors, street light poles, cityscapes, etc.) the distortion will be quite high, where the Sigma 10-20mm f/3.5 will present very low to nil distortion from about 12mm, and has constant aperture design for good low light capability at all its focal lengths. Now that you mention it, it is a very good point, often overlooked. The Sigma 10-20 is distortion free starting with 14mm if I remember correctly, whereas when I spin around my 16-85 at 16mm in the viewfinder I clearly see the distortion. Time to undust my 10-20.

04-23-2021, 03:36 PM	#32
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,560	Good idea! And the super wide angle of 10mm or even 14mm is vey impressive. Just be sure not to confuse wide angle perspective distortion, which can be avoided or improved sometimes just by positioning for a better angle, with linear distortion as it bends a straight line in the middle, even when shot at a perfect dead-on vertical angle. Those test grids for linear distortion tell the story.

04-30-2021, 12:27 AM - 3 Likes	#33
AlanM Forum Member Join Date: Mar 2020 Location: Søborg Posts: 61 Original Poster	Thanks for all your advice. I pulled the trigger and got the Pentax 11-18mm yesterday. It has a lot going for it and, after all, it's a Pentax and we all want Pentax to survive and prosper. Now I just need to improve my photographic skills to match the lens.

04-30-2021, 01:47 AM	#34
LittleSkink Senior Member Join Date: Jul 2008 Location: t'North Photos: Albums Posts: 166	The 11-18 is superb, from what I have seen - much envy here Not sure how you plan to use it, but having the 10-17 myself I see it much more of a novelty / fun lens (with a bunch of aberration issues to boot) while the 11-18 is a "proper grown up lens" with outstanding capabilities and almost nothing to see in terms of aberrations

04-30-2021, 10:52 AM	#35
bdery Pentaxian Join Date: Mar 2008 Location: Quebec city, Canada Photos: Gallery Posts: 9,362	Originally posted by AlanM Thanks for all your advice. I pulled the trigger and got the Pentax 11-18mm yesterday. It has a lot going for it and, after all, it's a Pentax and we all want Pentax to survive and prosper. Congrats on this purchase, it will serve you well.

04-30-2021, 03:16 PM	#36
Bertrand3000 Veteran Member Join Date: Feb 2019 Posts: 2,009	Congratulations for your purchase. You cannot go wrong with the 11-18.

04-30-2021, 06:17 PM	#37
MrNPhoto Loyal Site Supporter Join Date: Aug 2014 Location: Boston Photos: Gallery Posts: 276	Agreed, the 11-18 is excellent all around.

04-30-2021, 07:13 PM	#38
caliscouser Site Supporter Join Date: Sep 2014 Location: SF Bay Area, CA Photos: Albums Posts: 1,037	Congrats the 11-18 is a no compromise lens unlike the the other options.