Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
02-26-2017, 03:50 AM   #1
New Member

Join Date: Jan 2016
Posts: 1
K1 with Sigma DC 18-250 Macro HSM

I'm looking to upgrade from my K3-II and I would like to keep my DC 18-250 as a walking around lens.

Anyone tried one of these on the K1?

02-26-2017, 04:16 AM   #2
kooks's Avatar

Join Date: Apr 2011
Location: San Josť, Costa Rica
Photos: Albums
Posts: 794
It will work.. using it at APC crop mode but not as a FF lens.
02-26-2017, 06:12 AM   #3
Loyal Site Supporter
Loyal Site Supporter

Join Date: Feb 2010
Location: Maryland
Posts: 468
I occasionally use my 18-250 Pentax DA on the K-1 in crop mode. You probably can get away with the 1:1 crop mode for a 24 Mp image using the Sigma. Be aware that through the viewfinder you will see a large vignetted image with a black box indicating crop mode. If you don't like this effect, you can use live view which works normally. Personally I am not a fan of crop mode as a general solution because of this effect which impacts composition in the viewfinder taking away one of the advantages of the DSLR.
02-26-2017, 06:28 AM   #4
Loyal Site Supporter
Loyal Site Supporter
dakight's Avatar

Join Date: Sep 2014
Location: Phoenix, AZ
Photos: Albums
Posts: 1,216
I suppose it should go without saying, but one always has the option to shoot in full frame mode then crop in post. There is no reason at all to be bound by the built in crop ratios.

02-26-2017, 06:56 AM   #5
Forum Member

Join Date: Mar 2013
Location: Slovakia
Posts: 63
K-1 + DA18-135WR



left - FF mode and manualy crop in editor
right - APS-C mode in K-1
02-26-2017, 07:14 AM   #6
Senior Member

Join Date: Feb 2012
Posts: 183
The comparison between crop and crop seems to be somewhat ... futile.

More interesting would be a non-cropped FF image. Yes, that'll be with severe vignetting, but depending on the lens' construction and the focal length chosen, this could change, and there's even some chance for less vignetting with longer focal lenghts.

Could you post non-cropped FF images to compare them with APS-C crops?
02-26-2017, 11:48 AM   #7
Forum Member

Join Date: Mar 2013
Location: Slovakia
Posts: 63
K1 + DA18-135WR

18mm f11 FF vs APS-C

135mm f11 FF vs APS-C

full size JPG!ccrzkwq3vm9l/da18-135-k1-rar
02-26-2017, 12:03 PM   #8
Senior Member

Join Date: Feb 2012
Posts: 183
You're aware that you can post images as part of this forum without using external file sharing services?

02-26-2017, 12:48 PM   #9
Forum Member

Join Date: Mar 2013
Location: Slovakia
Posts: 63
if the AF focus is correct, details are the same, from FF mode and APS-C mode.

attachment JPG can be maximum 1400x900 pix
Attached Images
02-26-2017, 12:49 PM   #10

Join Date: Mar 2013
Posts: 360
If that was the question, Sigma DC lenses are not usable in full frame mode at any focal length and any apperture.
You'll have to use crop mode.
02-26-2017, 01:01 PM   #11
Senior Member

Join Date: Feb 2012
Posts: 183
QuoteOriginally posted by lennyl Quote
attachment JPG can be maximum 1400x900 pix
Oh, that explains things. I might have been not to clear in my words. By "uncropped" I did not mean an image in the 100% camera resolution, but an image that shows the vignetting that you have removed, that is, the unuseable parts of the full frame image.
02-26-2017, 01:24 PM   #12
Forum Member

Join Date: Mar 2013
Location: Slovakia
Posts: 63
if you want more examples, you can download full size JPGs from my previous post with FF mode vignetting and APS-C mode JPGs also.

i understand very well what you wrote. i want show the details in 1:1, thats all
for me is not APS-C/square mode solution, only a temporary solution who has not yet FF lenses

orignal APS-C lenses have brutal vignetting - for example DA15/4, DA18-135WR and others
02-26-2017, 01:35 PM   #13
Senior Member

Join Date: Feb 2012
Posts: 183
Comparing a manual crop (done in post-processing from a full-frame shot) to an in-camera crop is quite pointless, since the result is invariably the same.

Why the bother?
02-26-2017, 01:45 PM   #14
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 36,221
The main thing is on the K-1, it's going to be a full frame equivalent of 12mm-175mm, even if you could use the full frame. With my 60-250 I can use it in FF mode, but it's distressing how much more field of view is involved if you're used to the crop FoV.

  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
dc, dc 18-250 macro, dslr, full frame, full-frame, k-1, k1, k1 with sigma, pentax k-1, sigma dc, sigma dc 18-250 hsm macro
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Sigma 18-250/3.5-6.3 DC Macro HSM buster2015 Sold Items 6 06-27-2016 07:22 PM
$249.99 - Sigma 18-250 F3.5-6.3 DC Macro OS HSM with Optical Stabilizer glee46 Pentax Price Watch 4 08-09-2015 02:26 AM
For Sale - Sold: Sigma 18-250mm F3.5-6.3 DC Macro HSM for PENTAX 18-250 NEW (price reduced) transam879 Sold Items 9 08-12-2014 10:08 PM
Sigma 18-250 DC HSM Macro Lens Sample sumx4182 Lens Sample Photo Archive 14 03-07-2014 12:29 PM
Wanted - Acquired: Sigma 150-500mm HSM, 150mm MACRO HSM, Sigma 18-250 HSM, Sigma 10-20mm HSM mackloon Sold Items 7 05-01-2011 02:25 AM

All times are GMT -7. The time now is 03:15 PM. | See also:, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]