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gflauti · 01-30-2012, 01:49 PM

I would like to change my k-x and buy a k-5 expecially to improve autofocus speed and precision.

The question is:

Is the autofocus speed in k-5 a significant improvement with respect to k-x?

My question is for people that owned a k-x!

Thanks!

Anvh · 01-30-2012, 02:06 PM

My uncle has a Kx that i've used a couple of times, does that count?
The Kx is slower then the k5 but have no idea about the accuracy.

But the thing is no matter how you look at it the AF isn't the K5 selling point it's the handling of the camera and the image quality that makes it great.
If you want a major improvement in AF look at another brand, it's as simple as that.

Winder · 01-30-2012, 02:13 PM

K-5 AF has a color sensor to adjust for different light. The K-x does not. The K-5 is much faster and "should" be more accurate under different lighting conditions. Under normal "day light" conditions there should not be a significant difference in accuracy. But if you were taking pictures under red stage lighting the K-5 would be much faster and more accurate.

twitch · 01-30-2012, 02:21 PM

I have a K-x and a K-5 and find it's only a tiny difference in AF speed between the 2. The big difference though is being able to fine tune AF per lens, and the burst mode in AF-C is much faster too. I also like being able to do back button focusing without losing the AE-L function.

gflauti · 01-30-2012, 02:33 PM

Originally posted by Winder

K-5 AF has a color sensor to adjust for different light. The K-x does not. The K-5 is much faster and "should" be more accurate under different lighting conditions. Under normal "day light" conditions there should not be a significant difference in accuracy. But if you were taking pictures under red stage lighting the K-5 would be much faster and more accurate.

OK, I'm interested in accuracy more than speed. Expecially in artificial light.

Originally posted by twitch

I have a K-x and a K-5 and find it's only a tiny difference in AF speed between the 2. The big difference though is being able to fine tune AF per lens, and the burst mode in AF-C is much faster too. I also like being able to do back button focusing without losing the AE-L function.

I agree, could be the better improvement is the fine tune AF per lens. And this could improve the AF accuracy.

bobmaxja · 01-30-2012, 02:38 PM

Dont forget , lense is a major factor

wingman · 01-30-2012, 02:41 PM

I have the k-x and the k-5. k-5 seems to be better in low light. Daylight can’t tell any difference. Hope this helps.

wingman

gflauti · 01-30-2012, 02:54 PM

Originally posted by bobmaxja

Dont forget , lense is a major factor

I know...

I'm just wondering if replace my FA50 with a 70 or 77mm lens, or update camera before...

edit message:
Just to point out:
Replace FA50 with 70 or 77 is not for AF speed, but because I prefere a longer focal for portraits.
Replace camera is for both handling and AF speed.
I have limited money, so I have to decide what to do before...

JinDesu · 01-30-2012, 03:06 PM

Would the k-5 be better than the k-x when using super fast lenses like the 55 1.4?

twitch · 01-30-2012, 03:12 PM

Originally posted by gflauti

I know...

I'm just wondering if replace my FA50 with a 70 or 77mm lens, or update camera before...

For AF speed? Don't bother. While a DA70 is slightly faster, I don't think AF speed is a great reason to choose a prime of one focal length over another of a different focal length.

The FA50 is capable of stunning pictures, I have no hesitation using it over my FA or DA limiteds if the 50mm focal length is what I want. It's easily the best bargain of any brand new Pentax prime.

rawr · 01-30-2012, 03:16 PM

I find the K-5 more prompt and 'confident' in it's AF than the K-x, particularly in low-light. Also mostly more accurate, but I mainly use centre-spot AF-S so can't make any claims about matrix AF, AF-C etc.

It also seems that the K-5 AF motor has a bit more horsepower - it certainly seems to push the focus ring on the 55-300 in particular around more strongly.

The AF assist light is also useful on the K-5.

gflauti · 01-30-2012, 03:17 PM

Originally posted by JinDesu

Would the k-5 be better than the k-x when using super fast lenses like the 55 1.4?

Are you speaking about SDM lens?
My k-x works better with screw drive lens. FA 50 is much faster than DA 55.
I don't know if k-5 works better than k-x with SDM lens...

edit message:
Just to point out:
Replace FA50 with 70 or 77 is not for AF speed, but because I prefere a longer focal for portraits.
Replace camera is for both handling and AF speed.
I have limited money, so I have to decide what to do before...

Happyman · 01-30-2012, 03:55 PM

Just to put my two cents in: When I only had the k-x, I bought a brand new Tamron 17-50. To be honest, I was a bit disappointed with it's sharpness, I had been expecting more, based on the reviews. Then I bought a k-5 and suddenly my not-so-sharp Tammy got noticeably sharper! That's when I found out that the lack of sharpness on k-x was caused by the camera's focusing, not by the lens. I haven't done any detailed side-by-side testing, but I have a feeling that this (better focusing on k-5) is more pronounced in low-light situations.

JinDesu · 01-30-2012, 04:16 PM

Originally posted by gflauti

Are you speaking about SDM lens?
My k-x works better with screw drive lens. FA 50 is much faster than DA 55.
I don't know if k-5 works better than k-x with SDM lens...

edit message:
Just to point out:
Replace FA50 with 70 or 77 is not for AF speed, but because I prefere a longer focal for portraits.
Replace camera is for both handling and AF speed.
I have limited money, so I have to decide what to do before...

No, I mean fast lenses due to their thin DOF wreaking a bit of havoc on AF systems. I know that the higher end Canons have their special AF points meant for thin DOF lenses that are unactivated when using slower lenses. I don't know if the AF points on the k-5 are that different in design/software interpretation than the k-x. I use center point focus regardless of any situation (I'm stubborn).

Is the k-5 faster/more assertive/more accurate when using faster lenses (1.7 to 1.4)

forensicscientist · 01-30-2012, 07:05 PM

I have both and would add that outdoor, I don't see a big difference. Indoors, the K-5 might be a tad faster. That said, my K-x is just near perfect when comes to focus...all my lenses seem to be spot on. When using the K-5, a couple require some adjustment. The largest being my Sigma 24-60 2.8....which requires a -6 (or something close to that)....

thats my 2cents...hope it helps...

01-30-2012, 01:49 PM	#1
gflauti Junior Member Join Date: Dec 2010 Location: Naples (IT) Photos: Albums Posts: 44	Autofocus: k-5 vs k-x I would like to change my k-x and buy a k-5 expecially to improve autofocus speed and precision. The question is: Is the autofocus speed in k-5 a significant improvement with respect to k-x? My question is for people that owned a k-x! Thanks!

01-30-2012, 02:54 PM	#8
gflauti Junior Member Join Date: Dec 2010 Location: Naples (IT) Photos: Albums Posts: 44 Original Poster	Originally posted by bobmaxja Dont forget , lense is a major factor I know... I'm just wondering if replace my FA50 with a 70 or 77mm lens, or update camera before... edit message: Just to point out: Replace FA50 with 70 or 77 is not for AF speed, but because I prefere a longer focal for portraits. Replace camera is for both handling and AF speed. I have limited money, so I have to decide what to do before... Last edited by gflauti; 01-30-2012 at 03:23 PM. Reason: write better what I mean

01-30-2012, 03:17 PM	#12
gflauti Junior Member Join Date: Dec 2010 Location: Naples (IT) Photos: Albums Posts: 44 Original Poster	Originally posted by JinDesu Would the k-5 be better than the k-x when using super fast lenses like the 55 1.4? Are you speaking about SDM lens? My k-x works better with screw drive lens. FA 50 is much faster than DA 55. I don't know if k-5 works better than k-x with SDM lens... edit message: Just to point out: Replace FA50 with 70 or 77 is not for AF speed, but because I prefere a longer focal for portraits. Replace camera is for both handling and AF speed. I have limited money, so I have to decide what to do before... Last edited by gflauti; 01-30-2012 at 03:39 PM. Reason: improve text

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01-30-2012, 02:06 PM	#2
Anvh Veteran Member Join Date: Sep 2011 Posts: 4,616	My uncle has a Kx that i've used a couple of times, does that count? The Kx is slower then the k5 but have no idea about the accuracy. But the thing is no matter how you look at it the AF isn't the K5 selling point it's the handling of the camera and the image quality that makes it great. If you want a major improvement in AF look at another brand, it's as simple as that.

01-30-2012, 02:13 PM	#3
Winder Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 6,617	K-5 AF has a color sensor to adjust for different light. The K-x does not. The K-5 is much faster and "should" be more accurate under different lighting conditions. Under normal "day light" conditions there should not be a significant difference in accuracy. But if you were taking pictures under red stage lighting the K-5 would be much faster and more accurate.

01-30-2012, 02:21 PM	#4
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	I have a K-x and a K-5 and find it's only a tiny difference in AF speed between the 2. The big difference though is being able to fine tune AF per lens, and the burst mode in AF-C is much faster too. I also like being able to do back button focusing without losing the AE-L function.

01-30-2012, 02:33 PM	#5
gflauti Junior Member Join Date: Dec 2010 Location: Naples (IT) Photos: Albums Posts: 44 Original Poster	Originally posted by Winder K-5 AF has a color sensor to adjust for different light. The K-x does not. The K-5 is much faster and "should" be more accurate under different lighting conditions. Under normal "day light" conditions there should not be a significant difference in accuracy. But if you were taking pictures under red stage lighting the K-5 would be much faster and more accurate. OK, I'm interested in accuracy more than speed. Expecially in artificial light. Originally posted by twitch I have a K-x and a K-5 and find it's only a tiny difference in AF speed between the 2. The big difference though is being able to fine tune AF per lens, and the burst mode in AF-C is much faster too. I also like being able to do back button focusing without losing the AE-L function. I agree, could be the better improvement is the fine tune AF per lens. And this could improve the AF accuracy.

01-30-2012, 02:38 PM	#6
bobmaxja Veteran Member Join Date: Mar 2010 Location: Laval, Quebec Canada Posts: 2,171	Dont forget , lense is a major factor

01-30-2012, 02:41 PM	#7
wingman Site Supporter Join Date: Jun 2010 Location: Tampa Bay Fl. Posts: 57	I have the k-x and the k-5. k-5 seems to be better in low light. Daylight can’t tell any difference. Hope this helps. wingman

01-30-2012, 03:06 PM	#9
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Would the k-5 be better than the k-x when using super fast lenses like the 55 1.4?

01-30-2012, 03:12 PM	#10
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	Originally posted by gflauti I know... I'm just wondering if replace my FA50 with a 70 or 77mm lens, or update camera before... For AF speed? Don't bother. While a DA70 is slightly faster, I don't think AF speed is a great reason to choose a prime of one focal length over another of a different focal length. The FA50 is capable of stunning pictures, I have no hesitation using it over my FA or DA limiteds if the 50mm focal length is what I want. It's easily the best bargain of any brand new Pentax prime.

01-30-2012, 03:16 PM	#11
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	I find the K-5 more prompt and 'confident' in it's AF than the K-x, particularly in low-light. Also mostly more accurate, but I mainly use centre-spot AF-S so can't make any claims about matrix AF, AF-C etc. It also seems that the K-5 AF motor has a bit more horsepower - it certainly seems to push the focus ring on the 55-300 in particular around more strongly. The AF assist light is also useful on the K-5.

01-30-2012, 03:55 PM	#13
Happyman Forum Member Join Date: Oct 2011 Posts: 68	Just to put my two cents in: When I only had the k-x, I bought a brand new Tamron 17-50. To be honest, I was a bit disappointed with it's sharpness, I had been expecting more, based on the reviews. Then I bought a k-5 and suddenly my not-so-sharp Tammy got noticeably sharper! That's when I found out that the lack of sharpness on k-x was caused by the camera's focusing, not by the lens. I haven't done any detailed side-by-side testing, but I have a feeling that this (better focusing on k-5) is more pronounced in low-light situations.

01-30-2012, 04:16 PM	#14
JinDesu Veteran Member Join Date: Jun 2011 Location: New York City Photos: Gallery Posts: 5,638	Originally posted by gflauti Are you speaking about SDM lens? My k-x works better with screw drive lens. FA 50 is much faster than DA 55. I don't know if k-5 works better than k-x with SDM lens... edit message: Just to point out: Replace FA50 with 70 or 77 is not for AF speed, but because I prefere a longer focal for portraits. Replace camera is for both handling and AF speed. I have limited money, so I have to decide what to do before... No, I mean fast lenses due to their thin DOF wreaking a bit of havoc on AF systems. I know that the higher end Canons have their special AF points meant for thin DOF lenses that are unactivated when using slower lenses. I don't know if the AF points on the k-5 are that different in design/software interpretation than the k-x. I use center point focus regardless of any situation (I'm stubborn). Is the k-5 faster/more assertive/more accurate when using faster lenses (1.7 to 1.4)

01-30-2012, 07:05 PM	#15
forensicscientist Pentaxian Join Date: Jun 2008 Location: DFW Texas and Michigan - I commute :) Posts: 1,012	I have both and would add that outdoor, I don't see a big difference. Indoors, the K-5 might be a tad faster. That said, my K-x is just near perfect when comes to focus...all my lenses seem to be spot on. When using the K-5, a couple require some adjustment. The largest being my Sigma 24-60 2.8....which requires a -6 (or something close to that).... thats my 2cents...hope it helps...

Autofocus: k-5 vs k-x

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