Sigma 100-300 f4

jab2980 · 10-22-2020, 11:28 AM

edit: thought I was having issues with the lens, but it turns out that it just needed an in-camera AF adjustment

Last edited by jab2980; 09-21-2021 at 07:11 AM.

**marcusBMG** · 10-22-2020, 12:07 PM - **1 Like**

Well you can compare yours to the one I had - test pics here post :

300mm plus Lens Club: discuss your long lenses - Page 2190 - PentaxForums.com

f8, f11 I was pretty satisfied but like you I was expecting more at 300mm f4. I think which one you have is significant - there are successive generations, EX, EX DG... Mine was a film era EX.

jab2980 · 10-22-2020, 12:12 PM

Originally posted by marcusBMG

Well you can compare yours to the one I had - test pics here post :

300mm plus Lens Club: discuss your long lenses - Page 2190 - PentaxForums.com

f8, f11 I was pretty satisfied but like you I was expecting more at f4. I think which one you have is significant - there are successive generations, EX, EX DG... Mine was a film era EX.

Thank you. Mine is the EX DG

**luftfluss** · 10-22-2020, 12:35 PM - **1 Like**

Quite possible you are experiencing spherical aberration.

**pentageek** · 10-22-2020, 02:31 PM - **1 Like**

I've got EX DG, and at a first glance these pictures look surprisingly soft. However, I never tried to use my lens in 'pseudo macro' mode, i.e. when relatively small subjects are photographed from close distance. When used in proper 'tele' mode, it is one of two lenses (the other one is F 100/2.8 macro), which renders OOC pictures beautifully. I can test 'macro' mode next week if you are interested (I can do it with either K-S2 or K-1).

**JensE** · 10-22-2020, 03:42 PM - **1 Like**

I think Digitalis once reported that he observed quite some sample variation going through multiple of those lenses. Not untypical for this Sigma era, I'm afraid.

jab2980 · 10-22-2020, 06:39 PM

These are 100% crops. I am pixel peeping admittedly but I've read so many good reviews about this lens that I had high expectations for it. Thank you for the offer!

Originally posted by pentageek

I've got EX DG, and at a first glance these pictures look surprisingly soft. However, I never tried to use my lens in 'pseudo macro' mode, i.e. when relatively small subjects are photographed from close distance. When used in proper 'tele' mode, it is one of two lenses (the other one is F 100/2.8 macro), which renders OOC pictures beautifully. I can test 'macro' mode next week if you are interested (I can do it with either K-S2 or K-1).

**Lowell Goudge** · 10-23-2020, 04:22 AM - **1 Like**

At first glance they seem softer than what I get out of my 70-200/2.8 EX with either the 1.4 or 2x TC attached. The shots at F5.6 and F8 are noticeably improved from those at F4. Also when viewing a 100% crop on the K1, the shutter speed you use at 1/320 or 1/400 is not sufficient for hand held (Assumption on my part). You should let the shutter speed go up as well as the ISO.

You might also want to turn off shake reduction, especially if you let the shutter speed go up significantly.

Try the same shots with flash, because it will tell you how capable the lens really is as the flash duration is typically 20-50 microseconds( 1/50,000 to 1/20,000 And will truly freeze the image.

Also you are using MF, with focus assist, what about AF? Your DOF is really limited. Any focus error will make the lens appear soft

One last comment, I don’t know it this applies to the 100-300, but for the 70-200 from the same era, the last film version was the sharpest and as they added macro features, the maximum focal length wide open was soft, this was true up until the very last version made for Pentax. As the lens designs are very similar, the same may well apply to the 100-300

jab2980 · 10-23-2020, 01:37 PM

Thank you all for taking time to think about this and look into it. Based on your comments and suggestions plus another round of testing (as well as comparisons to my DA* 60-250 @250 and @135 and Samyang 135) I have concluded that it simply is a bit more soft/glowy than I expected at 250-300 f/4 through at least f/8 and slightly softer than the 60-250 between 135mm and 250mm. I love the look and feel of the lens and it actually creates really beautiful photographs when not pixel peeping. Side note, I really wish Samyang would make a 300mm equal to or greater than the 135 f/2.0.... that's an incredible lens.

Mike.P® · 10-24-2020, 05:45 AM - **1 Like**

I took my 100-300mm DG EX out this morning and despite the weather being very poor I took a couple of test shots with my K-1. These were 300mm wide open, handheld with SR off and no processing. Personally I think yours are quite soft but here are mine along with 100% crops plus the second crop had a little processing.

jab2980 · 10-26-2020, 12:53 PM

Originally posted by Mike.P®

I took my 100-300mm DG EX out this morning and despite the weather being very poor I took a couple of test shots with my K-1. These were 300mm wide open, handheld with SR off and no processing. Personally I think yours are quite soft but here are mine along with 100% crops plus the second crop had a little processing.

Thank you for taking the time to do this - it is very helpful.

10-22-2020, 11:28 AM	#1
jab2980 Pentaxian Join Date: Apr 2013 Location: Pittsburgh, PA Photos: Albums Posts: 578	Sigma 100-300 f4 edit: thought I was having issues with the lens, but it turns out that it just needed an in-camera AF adjustment Last edited by jab2980; 09-21-2021 at 07:11 AM.

10-22-2020, 12:07 PM - 1 Like	#2
marcusBMG Site Supporter Join Date: Nov 2012 Location: North Wales Photos: Gallery \| Albums Posts: 2,868	Well you can compare yours to the one I had - test pics here post : 300mm plus Lens Club: discuss your long lenses - Page 2190 - PentaxForums.com f8, f11 I was pretty satisfied but like you I was expecting more at 300mm f4. I think which one you have is significant - there are successive generations, EX, EX DG... Mine was a film era EX. Last edited by marcusBMG; 10-22-2020 at 12:13 PM.

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10-22-2020, 12:12 PM	#3
jab2980 Pentaxian Join Date: Apr 2013 Location: Pittsburgh, PA Photos: Albums Posts: 578 Original Poster	Originally posted by marcusBMG Well you can compare yours to the one I had - test pics here post : 300mm plus Lens Club: discuss your long lenses - Page 2190 - PentaxForums.com f8, f11 I was pretty satisfied but like you I was expecting more at f4. I think which one you have is significant - there are successive generations, EX, EX DG... Mine was a film era EX. Thank you. Mine is the EX DG

10-22-2020, 12:35 PM - 1 Like	#4
luftfluss Site Supporter Join Date: Jun 2011 Location: NJ Photos: Gallery \| Albums Posts: 11,618	Quite possible you are experiencing spherical aberration.

10-22-2020, 02:31 PM - 1 Like	#5
pentageek Site Supporter Join Date: Jan 2016 Posts: 420	I've got EX DG, and at a first glance these pictures look surprisingly soft. However, I never tried to use my lens in 'pseudo macro' mode, i.e. when relatively small subjects are photographed from close distance. When used in proper 'tele' mode, it is one of two lenses (the other one is F 100/2.8 macro), which renders OOC pictures beautifully. I can test 'macro' mode next week if you are interested (I can do it with either K-S2 or K-1).

10-22-2020, 03:42 PM - 1 Like	#6
JensE Site Supporter Join Date: Dec 2015 Location: Leipzig Photos: Gallery \| Albums Posts: 1,964	I think Digitalis once reported that he observed quite some sample variation going through multiple of those lenses. Not untypical for this Sigma era, I'm afraid.

10-22-2020, 06:39 PM	#7
jab2980 Pentaxian Join Date: Apr 2013 Location: Pittsburgh, PA Photos: Albums Posts: 578 Original Poster	These are 100% crops. I am pixel peeping admittedly but I've read so many good reviews about this lens that I had high expectations for it. Thank you for the offer! Originally posted by pentageek I've got EX DG, and at a first glance these pictures look surprisingly soft. However, I never tried to use my lens in 'pseudo macro' mode, i.e. when relatively small subjects are photographed from close distance. When used in proper 'tele' mode, it is one of two lenses (the other one is F 100/2.8 macro), which renders OOC pictures beautifully. I can test 'macro' mode next week if you are interested (I can do it with either K-S2 or K-1).

10-23-2020, 04:22 AM - 1 Like	#8
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,886	At first glance they seem softer than what I get out of my 70-200/2.8 EX with either the 1.4 or 2x TC attached. The shots at F5.6 and F8 are noticeably improved from those at F4. Also when viewing a 100% crop on the K1, the shutter speed you use at 1/320 or 1/400 is not sufficient for hand held (Assumption on my part). You should let the shutter speed go up as well as the ISO. You might also want to turn off shake reduction, especially if you let the shutter speed go up significantly. Try the same shots with flash, because it will tell you how capable the lens really is as the flash duration is typically 20-50 microseconds( 1/50,000 to 1/20,000 And will truly freeze the image. Also you are using MF, with focus assist, what about AF? Your DOF is really limited. Any focus error will make the lens appear soft One last comment, I don’t know it this applies to the 100-300, but for the 70-200 from the same era, the last film version was the sharpest and as they added macro features, the maximum focal length wide open was soft, this was true up until the very last version made for Pentax. As the lens designs are very similar, the same may well apply to the 100-300

10-23-2020, 01:37 PM	#9
jab2980 Pentaxian Join Date: Apr 2013 Location: Pittsburgh, PA Photos: Albums Posts: 578 Original Poster	Thank you all for taking time to think about this and look into it. Based on your comments and suggestions plus another round of testing (as well as comparisons to my DA* 60-250 @250 and @135 and Samyang 135) I have concluded that it simply is a bit more soft/glowy than I expected at 250-300 f/4 through at least f/8 and slightly softer than the 60-250 between 135mm and 250mm. I love the look and feel of the lens and it actually creates really beautiful photographs when not pixel peeping. Side note, I really wish Samyang would make a 300mm equal to or greater than the 135 f/2.0.... that's an incredible lens.

10-24-2020, 05:45 AM - 1 Like	#10
Mike.P® Veteran Member Join Date: Mar 2008 Location: New Milton, Hampshire, UK Photos: Gallery \| Albums Posts: 2,154	I took my 100-300mm DG EX out this morning and despite the weather being very poor I took a couple of test shots with my K-1. These were 300mm wide open, handheld with SR off and no processing. Personally I think yours are quite soft but here are mine along with 100% crops plus the second crop had a little processing.

10-26-2020, 12:53 PM	#11
jab2980 Pentaxian Join Date: Apr 2013 Location: Pittsburgh, PA Photos: Albums Posts: 578 Original Poster	Originally posted by Mike.P® I took my 100-300mm DG EX out this morning and despite the weather being very poor I took a couple of test shots with my K-1. These were 300mm wide open, handheld with SR off and no processing. Personally I think yours are quite soft but here are mine along with 100% crops plus the second crop had a little processing. Thank you for taking the time to do this - it is very helpful.

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