K1 with 28-105 D FA lens and 1.4x Teleconverter

**i_trax** · 12-21-2019, 11:30 PM - **1 Like**

right now my Tamron is attached to K-3 II and Sigma 18-300 (3.5 - 6.3 rather slow lens ) and do not have a problem with AF even indoors.
I do have :
HD Pentax-DA 1.4x AW AF Rear Converter but never use it, should sell it.

biz-engineer · 12-22-2019, 05:14 AM - **1 Like**

Originally posted by ozarun55

K1 with 28-105 D FA lens and 1.4x Teleconverter

it is not a good idea to stack a TC on a f5.6 lens, especially a zoom lens.

**gaweidert** · 12-22-2019, 05:56 AM

I do have a 55-300mm lens that I like, It is not the PLM version and autofocus searches quite a bit. I often find manual focus quicker. The PLM version is much better in this regard. Still the images are pretty good and probably better than what one would get with the 28-105 lens with a teleconverter attached.

aaacb · 12-22-2019, 06:17 AM

I recently got a k1ii and the 28-105. My older landscape kit is the k3ii + 16-85 + 55-300. I didn't want to use crop mode, and the cost+weight of the 70-200 f2.8 was prohibitive.

Instead I ordered an old manual 70-210 lens to cover the range from 100 to 200. Judging by reviews, image quality should be plenty for how I'm planning to use it (stopped down to f8-f11) but I have yet to receive the lens. Mine is the vivitar series 1 version 2, the pentax a 70-210 may be lighter weight.

**JensE** · 12-22-2019, 06:30 AM - **1 Like**

Just slapped the DA TC + 28-105 on my K-1: Autofocus is surprisingly decisive and accurate (DoF at effectively f/8.0 is not vet shallow anyway), even in my currently dark office (ISO 12800, f/8 and 1/6s with -0.3 exposure correction). Corners are fairly dark at f/8 but image circle is much bigger than APS-C and square crop, I'd say about 5:4 would work.

**ozarun55** · 12-22-2019, 03:02 PM - **1 Like**

See - even here amongst the community people have very different opinions ;-). I guess the one saving grace of 28-105 with k1 is with 36mp you can crop quite heavily (and I have good enlarging software if I need a higher resolution for prints) but it's not ideal really.

@aaacb I'll check out the 70-210... haven't heard much about it, though just at a quick look seems hard to find many copies in good condition. Although I wonder how fiddly MF would be at the 210 end.

Qman · 12-22-2019, 04:57 PM

There are lots of autofocus 70-210 lenses around. The F 70-210 gets good reviews. Bigger and heavier than the 135mm f2.8, but much cheaper and longer reach.

**ozarun55** · 12-22-2019, 08:38 PM

The 70-210 is a good suggestion although some have suggested it is not a great landscape lens due to the lack of infinity focus?. Can't see many copies lying around though, guess I'll have to keep my eye out.

12-22-2019, 03:02 PM - 1 Like	#21
ozarun55 Site Supporter Join Date: Nov 2017 Posts: 50 Original Poster	See - even here amongst the community people have very different opinions ;-). I guess the one saving grace of 28-105 with k1 is with 36mp you can crop quite heavily (and I have good enlarging software if I need a higher resolution for prints) but it's not ideal really. @aaacb I'll check out the 70-210... haven't heard much about it, though just at a quick look seems hard to find many copies in good condition. Although I wonder how fiddly MF would be at the 210 end. Last edited by ozarun55; 12-22-2019 at 03:08 PM.

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12-21-2019, 11:30 PM - 1 Like	#16
i_trax Loyal Site Supporter Join Date: Jan 2011 Location: Perth Western Australia Photos: Gallery \| Albums Posts: 2,621	right now my Tamron is attached to K-3 II and Sigma 18-300 (3.5 - 6.3 rather slow lens ) and do not have a problem with AF even indoors. I do have : HD Pentax-DA 1.4x AW AF Rear Converter but never use it, should sell it.

12-22-2019, 05:14 AM - 1 Like	#17
biz-engineer Pentaxian Join Date: Feb 2015 Photos: Gallery Posts: 12,247	Originally posted by ozarun55 K1 with 28-105 D FA lens and 1.4x Teleconverter it is not a good idea to stack a TC on a f5.6 lens, especially a zoom lens.

12-22-2019, 05:56 AM	#18
gaweidert Loyal Site Supporter Join Date: Mar 2012 Location: Rochester, NY Photos: Gallery Posts: 5,327	I do have a 55-300mm lens that I like, It is not the PLM version and autofocus searches quite a bit. I often find manual focus quicker. The PLM version is much better in this regard. Still the images are pretty good and probably better than what one would get with the 28-105 lens with a teleconverter attached.

12-22-2019, 06:17 AM	#19
aaacb Pentaxian Join Date: May 2016 Photos: Gallery Posts: 3,726	I recently got a k1ii and the 28-105. My older landscape kit is the k3ii + 16-85 + 55-300. I didn't want to use crop mode, and the cost+weight of the 70-200 f2.8 was prohibitive. Instead I ordered an old manual 70-210 lens to cover the range from 100 to 200. Judging by reviews, image quality should be plenty for how I'm planning to use it (stopped down to f8-f11) but I have yet to receive the lens. Mine is the vivitar series 1 version 2, the pentax a 70-210 may be lighter weight.

12-22-2019, 06:30 AM - 1 Like	#20
JensE Site Supporter Join Date: Dec 2015 Location: Leipzig Photos: Gallery \| Albums Posts: 1,975	Just slapped the DA TC + 28-105 on my K-1: Autofocus is surprisingly decisive and accurate (DoF at effectively f/8.0 is not vet shallow anyway), even in my currently dark office (ISO 12800, f/8 and 1/6s with -0.3 exposure correction). Corners are fairly dark at f/8 but image circle is much bigger than APS-C and square crop, I'd say about 5:4 would work.

12-22-2019, 04:57 PM	#22
Qman Senior Member Join Date: Jun 2017 Posts: 232	There are lots of autofocus 70-210 lenses around. The F 70-210 gets good reviews. Bigger and heavier than the 135mm f2.8, but much cheaper and longer reach.

12-22-2019, 08:38 PM	#23
ozarun55 Site Supporter Join Date: Nov 2017 Posts: 50 Original Poster	The 70-210 is a good suggestion although some have suggested it is not a great landscape lens due to the lack of infinity focus?. Can't see many copies lying around though, guess I'll have to keep my eye out.