Fast Autofocus primes

0zerec · 03-25-2015, 03:11 PM

Hey guys... Just ordered my KS2 and I'm pretty stoked about it. This is going to be my personal/video camera.

What I'm looking for is fast AF primes. All I see is a 35mm 2.4... Is there anything faster in the 35mm focal length?

Also I'll take any recommendations as I am new to owning a pentax

thanks guys and gals!

stillshot2 · 03-25-2015, 03:17 PM

There's the FA 35mm f2 and the Limited 31mm f1.8, both costing quite a bit more.

Adam · 03-25-2015, 03:18 PM

Yup, there's the Sigma 35mm F1.4 (big but optically outstanding), Pentax 31 F1.8, and plenty of legacy Sigma 28mm F1.8 variants.

Stavri · 03-25-2015, 03:54 PM

The fastest AF lenses are FA* 85/f1.4, the F/FA 135/f2.8, F/FA 28/f2.8, F*/FA* 300mm f4.5 (do you notice a pattern....) in that order. In general all the F/FA screw drive primes (and zooms) are quite fast focusing...

aussiejames101 · 03-25-2015, 04:24 PM

Sigma 30mm F1.4, either the old EX version or the new Art version. I have the newer Art version and it's my favourite lens, silent fast focusing and sharp wide open. Quite a bulky lens compared to the 35 F2.4 but it's got a lot of glass and it's very solidly built.

Stavri · 03-25-2015, 04:43 PM

Originally posted by aussiejames101

Sigma 30mm F1.4, either the old EX version or the new Art version. I have the newer Art version and it's my favourite lens, silent fast focusing and sharp wide open. Quite a bulky lens compared to the 35 F2.4 but it's got a lot of glass and it's very solidly built.

I have the older EX 30mm f1.4 and it's notoriety for extreme center sharpness at low aperture is well deserved. Apart from some focus adjustment the lens performs well in most circumstance except for low light. I noticed this rather recently on a small photoshoot I was partaking. The Ex 30 had issues focusing accurately on the model due to the soft lighting I was using at the time, one in four images were out of focus. I ended up switching to the DA* 55/1.4 to wrap things up. The lens has otherwise been a solid performer in most situations. I don't have experience with the 30mm f1.4 Art, but the 18-35mm that I own needed the usb dock too dial in the adjustments.

As much as i like the Ex 30, the Fa 35/2 is a very good replacement, past f2.8 both lenses deliver the same level of sharpness, the ex is 1/2 stop faster. Between the two I'd sacrifice the speed for the focus reliability and go with the Fa 35/f2

LightBug · 03-25-2015, 05:00 PM

DA 40mm is pretty speedy.

stevebrot · 03-25-2015, 05:43 PM

I own the FA 35/2 and consider it to be one of those lenses that I will never sell. Unfortunately, the current price point sort of squelches the value proposition (I paid $299.99 USD in 2008), but perhaps a good used copy?

Steve

calsan · 03-25-2015, 06:47 PM

You actually might not need as much speed as you are expecting, if you are coming from an older camera...

hcc · 03-25-2015, 08:52 PM

Originally posted by calsan

You actually might not need as much speed as you are expecting, if you are coming from an older camera...

+1. Newer cameras are more tolerant to high ISO.

quh86 · 03-26-2015, 01:32 AM

be careful though, screw drive is audible when you are recording sound on the same device. not quite in your focal range, but the 21mm ltd is very fast to focus, beatiful rendering and i just LOVE its fov.
what you could consider maybe is the 20-40, that should be a lot quieter, i dont know about AF speed tho

0zerec · 03-26-2015, 05:53 AM

Sigma 30mm 1.4 ART might be exactly what I'm looking for. I have the 35 1.4 art for nikon and it's amazing. I've also had the 50 art.

Too bad there aren't any pentax lenses that are that fast.

---------- Post added 03-26-15 at 05:55 AM ----------

Originally posted by hcc

+1. Newer cameras are more tolerant to high ISO.

I shoot 2 nikon D750's and a Fuji x100t... Pretty used to fast lenses 😁

redcat · 03-26-2015, 06:44 AM

fa 31mm is a great lens, I tried the sigma 35mm Art (shot this lens exclusively in a whole month) and still prefer the FA 31mm, the autofocus is great (a little noisy) and the IQ is superb !

**TER-OR** · 03-26-2015, 08:17 AM

I have a Sigma 28mm f1.8 macro, it's nice but it's big.

With ISO capability of modern sensors, little lenses like the DA 21mm pancake are very attractive.

03-25-2015, 03:11 PM	#1
0zerec New Member Join Date: Feb 2015 Posts: 8	Fast Autofocus primes Hey guys... Just ordered my KS2 and I'm pretty stoked about it. This is going to be my personal/video camera. What I'm looking for is fast AF primes. All I see is a 35mm 2.4... Is there anything faster in the 35mm focal length? Also I'll take any recommendations as I am new to owning a pentax thanks guys and gals!

03-25-2015, 03:18 PM	#3
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	Yup, there's the Sigma 35mm F1.4 (big but optically outstanding), Pentax 31 F1.8, and plenty of legacy Sigma 28mm F1.8 variants. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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03-25-2015, 03:17 PM	#2
stillshot2 Pentaxian Join Date: Sep 2013 Location: Phoenix, AZ Photos: Albums Posts: 1,070	There's the FA 35mm f2 and the Limited 31mm f1.8, both costing quite a bit more.

03-25-2015, 03:54 PM	#4
Stavri Veteran Member Join Date: Aug 2014 Location: at a Bean & Leaf Photos: Albums Posts: 1,832	The fastest AF lenses are FA* 85/f1.4, the F/FA 135/f2.8, F/FA 28/f2.8, F/FA 300mm f4.5 (do you notice a pattern....) in that order. In general all the F/FA screw drive primes (and zooms) are quite fast focusing...

03-25-2015, 04:24 PM	#5
aussiejames101 New Member Join Date: Mar 2015 Posts: 1	Sigma 30mm F1.4, either the old EX version or the new Art version. I have the newer Art version and it's my favourite lens, silent fast focusing and sharp wide open. Quite a bulky lens compared to the 35 F2.4 but it's got a lot of glass and it's very solidly built.

03-25-2015, 04:43 PM	#6
Stavri Veteran Member Join Date: Aug 2014 Location: at a Bean & Leaf Photos: Albums Posts: 1,832	Originally posted by aussiejames101 Sigma 30mm F1.4, either the old EX version or the new Art version. I have the newer Art version and it's my favourite lens, silent fast focusing and sharp wide open. Quite a bulky lens compared to the 35 F2.4 but it's got a lot of glass and it's very solidly built. I have the older EX 30mm f1.4 and it's notoriety for extreme center sharpness at low aperture is well deserved. Apart from some focus adjustment the lens performs well in most circumstance except for low light. I noticed this rather recently on a small photoshoot I was partaking. The Ex 30 had issues focusing accurately on the model due to the soft lighting I was using at the time, one in four images were out of focus. I ended up switching to the DA* 55/1.4 to wrap things up. The lens has otherwise been a solid performer in most situations. I don't have experience with the 30mm f1.4 Art, but the 18-35mm that I own needed the usb dock too dial in the adjustments. As much as i like the Ex 30, the Fa 35/2 is a very good replacement, past f2.8 both lenses deliver the same level of sharpness, the ex is 1/2 stop faster. Between the two I'd sacrifice the speed for the focus reliability and go with the Fa 35/f2

03-25-2015, 05:00 PM	#7
LightBug Veteran Member Join Date: Nov 2007 Location: OC, CA, USA Posts: 506	DA 40mm is pretty speedy.

03-25-2015, 05:43 PM	#8
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	I own the FA 35/2 and consider it to be one of those lenses that I will never sell. Unfortunately, the current price point sort of squelches the value proposition (I paid $299.99 USD in 2008), but perhaps a good used copy? Steve

03-25-2015, 06:47 PM	#9
calsan Pentaxian Join Date: Nov 2008 Location: Perth, Australia Photos: Gallery Posts: 1,548	You actually might not need as much speed as you are expecting, if you are coming from an older camera...

03-25-2015, 08:52 PM	#10
hcc Pentaxian Join Date: Nov 2009 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 4,001	Originally posted by calsan You actually might not need as much speed as you are expecting, if you are coming from an older camera... +1. Newer cameras are more tolerant to high ISO.

03-26-2015, 01:32 AM	#11
quh86 Senior Member Join Date: Oct 2013 Photos: Gallery \| Albums Posts: 157	be careful though, screw drive is audible when you are recording sound on the same device. not quite in your focal range, but the 21mm ltd is very fast to focus, beatiful rendering and i just LOVE its fov. what you could consider maybe is the 20-40, that should be a lot quieter, i dont know about AF speed tho

03-26-2015, 05:53 AM	#12
0zerec New Member Join Date: Feb 2015 Posts: 8 Original Poster	Sigma 30mm 1.4 ART might be exactly what I'm looking for. I have the 35 1.4 art for nikon and it's amazing. I've also had the 50 art. Too bad there aren't any pentax lenses that are that fast. ---------- Post added 03-26-15 at 05:55 AM ---------- Originally posted by hcc +1. Newer cameras are more tolerant to high ISO. I shoot 2 nikon D750's and a Fuji x100t... Pretty used to fast lenses 😁

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03-26-2015, 06:44 AM	#13
redcat Veteran Member Join Date: Jul 2014 Location: Paris Photos: Gallery Posts: 1,939	fa 31mm is a great lens, I tried the sigma 35mm Art (shot this lens exclusively in a whole month) and still prefer the FA 31mm, the autofocus is great (a little noisy) and the IQ is superb !

03-26-2015, 08:17 AM	#14
TER-OR Site Supporter Join Date: Apr 2009 Location: Dundee, IL Photos: Gallery \| Albums Posts: 6,699	I have a Sigma 28mm f1.8 macro, it's nice but it's big. With ISO capability of modern sensors, little lenses like the DA 21mm pancake are very attractive.