K-X Autofocus in low light?

planedriver · 12-06-2009, 04:07 AM

Hi Everyone ! Hands on experiences, comments and comparisons are welcomed about this topic.

Thanks

Andras

Muggins · 12-06-2009, 05:51 AM

Much better than my K200D, that's for sure. Of course it depends on the contrast between the subject and the background.

WerTicus · 12-06-2009, 09:18 AM

it can focus in lower light than i can see

UnknownVT · 12-06-2009, 10:35 AM

Originally posted by planedriver

Hi Everyone ! Hands on experiences, comments and comparisons are welcomed about this topic.

I understand that the Kx has the same AF as the Pentax K7?

If so, then "on paper" it is slower than the current equivalent Canon or Nikon -

crops from Popular Photography tests one of the very few places that actually test AF at different light levels.

As one can see at lower light levels the K7 could take TWICE as long as the Canon or Nikon....

BUT I own and have used the Kx for my shooting which is mainly musicians on stage - and I have found the Kx AF positive and fast enough for my (critical) usage.

But I only use the central AF point and always pre-focus - even when shooting a series - I focus on the face/eye hold re-compose then shoot - even doing that I can get quite a rapid rate of fire.... and have not felt as if the Kx is slowing me down.

EDIT to ADD -

Here are a couple of shots from a club where it was pretty dark -

EXIF re-attached.

rest of album - link to first pic in series -
Picasa Web Albums - UnknownVincent - Last Waltz En...
(25 pics mostly on the Kx 3:2 aspect ratio - any 4:3 aspect ratio are from the Canon G10)

The second shot was at approx 4 foot-candles or 44lux or EV=4 - this is pretty low.

Last edited by UnknownVT; 12-06-2009 at 11:07 AM. Reason: added sample photos

SteveB · 12-06-2009, 12:30 PM

A test in Feb 2010 Computer Shopper calls the Kx AF fast and the Canon T1i (500D) very inaccurate and they had to use manual focus to get any sharp shots. No D300 unfortunately but that's not really a competitor anyway as it costs more. The D90 sounded about the same as the Kx for speed. No figures unfortunately but they are usually quite thorough in their tests and don't seem biased.

Other tit-bits......
Kx was the lowest noise.

They down-rated the Kx for high premium lens prices and no AF VF points.

One big Kx plus was the fact that the kit lens was the sharpest out of Canon, Nikon, Sony and Olympus, and was almost as good as the 50mm primes of the other manufacturers for detail.

The T1i was amazingly slow at continuous 0.9fps RAW shooting after the buffer filled, the Kx carries on at 2fps (fast cards).

D90 video was not good due to 'lurching' auto exposure and very poor sound, Canon was juddery at 20fps. Kx video was excellent, sound OKish.

SteveB · 12-06-2009, 12:36 PM

Originally posted by WerTicus

it can focus in lower light than i can see

Can it AF on a black cat in a room lit by one low energy bulb? My K100D can't do this to save its life, even with a Sigma flash assist light. No black cats with white patches allowed, must be black

UnknownVT · 12-06-2009, 12:53 PM

Originally posted by SteveB

A test in Feb 2010 Computer Shopper calls the Kx AF fast and the Canon T1i (500D) very inaccurate and they had to use manual focus to get any sharp shots. No D300 unfortunately but that's not really a competitor anyway as it costs more. The D90 sounded about the same as the Kx for speed. No figures unfortunately but they are usually quite thorough in their tests and don't seem biased.

Nice to read this - however it seems from the majority of reviews out there that the Canon T1i does not appear to have any focusing issues - and since the T1i is such a popular camera there are numerous reviews out there.

However as I said I don't find the Kx slowing me down -
and it is certainly more positive and faster than my K100D

Originally posted by SteveB

Kx was the lowest noise.

Again this is general agreement with most findings by users and confirmed with the standardized and consistent test shots on Imaging-Resource -

Of all the APS-C sized sensors I feel the Kx has the best high ISO performance -
and I am astounded by a dSLR of such a reasonable price -
side-by-side comparisons with the test images on the aforementioned Imaging-Resource - the Kx for me was better than the Nikon D300S, D5000 and D90; Canons 7D. T1i

Originally posted by SteveB

One big Kx plus was the fact that the kit lens was the sharpest out of Canon, Nikon, Sony and Olympus, and was almost as good as the 50mm primes of the other manufacturers for detail.

This is how I have always felt about the two basic "kit" lenses (the 50-200 is even better) - they give absolutely nothing away in terms of image quality and AF ability when compared to more expensive lenses.

That's always been then reputation of Pentax of having really quality for much less than expected.

I was convinced by Popular Photography's reviews of the Samsung versions of those two lenses:

Lens Test: Schneider-Kreuznach D-Xenon 18-55mm f/3.5-5.6 AF

Lens Test: Schneider-Kreuznach D-Xenon 50-200mm f/4-5.6 AF

Pity they did not include their useful SQF table -
EDIT to ADD
here are scans of the SQF from my copy of the magazine -

Last edited by UnknownVT; 12-06-2009 at 01:14 PM. Reason: added scans of SQF tables

bymy141 · 12-07-2009, 07:49 AM

Originally posted by UnknownVT

I understand that the Kx has the same AF as the Pentax K7?

If so, then "on paper" it is slower than the current equivalent Canon or Nikon -

crops from Popular Photography tests one of the very few places that actually test AF at different light levels.

As one can see at lower light levels the K7 could take TWICE as long as the Canon or Nikon....

BUT I own and have used the Kx for my shooting which is mainly musicians on stage - and I have found the Kx AF positive and fast enough for my (critical) usage.

But I only use the central AF point and always pre-focus - even when shooting a series - I focus on the face/eye hold re-compose then shoot - even doing that I can get quite a rapid rate of fire.... and have not felt as if the Kx is slowing me down.

I don't know about test setups versus practical use.
However, I've been shooting wild life in darkness, shoulder to shoulder with 450D and 500D users.
Combined with a DA*6-250mm my K-7 was allways the fastest to lock focus and the most accurate.

If the K-x uses the same AF system, you should not worry...

WerTicus · 12-07-2009, 10:42 AM

Originally posted by SteveB

Can it AF on a black cat in a room lit by one low energy bulb? My K100D can't do this to save its life, even with a Sigma flash assist light. No black cats with white patches allowed, must be black

Not sure, i only tested it on a black space cat flying through a black hole in space.

12-06-2009, 04:07 AM	#1
planedriver Inactive Account Join Date: Feb 2009 Location: Velence, Hungary Posts: 664	K-X Autofocus in low light? Hi Everyone ! Hands on experiences, comments and comparisons are welcomed about this topic. Thanks Andras

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12-06-2009, 05:51 AM	#2
Muggins Junior Member Join Date: Jul 2009 Location: London Photos: Gallery Posts: 42	Much better than my K200D, that's for sure. Of course it depends on the contrast between the subject and the background.

12-06-2009, 09:18 AM	#3
WerTicus Veteran Member Join Date: Mar 2009 Location: Perth Australia Photos: Albums Posts: 1,514	it can focus in lower light than i can see

12-06-2009, 10:35 AM	#4
UnknownVT Veteran Member Join Date: Sep 2007 Location: USA Posts: 1,812	Originally posted by planedriver Hi Everyone ! Hands on experiences, comments and comparisons are welcomed about this topic. I understand that the Kx has the same AF as the Pentax K7? If so, then "on paper" it is slower than the current equivalent Canon or Nikon - crops from Popular Photography tests one of the very few places that actually test AF at different light levels. As one can see at lower light levels the K7 could take TWICE as long as the Canon or Nikon.... BUT I own and have used the Kx for my shooting which is mainly musicians on stage - and I have found the Kx AF positive and fast enough for my (critical) usage. But I only use the central AF point and always pre-focus - even when shooting a series - I focus on the face/eye hold re-compose then shoot - even doing that I can get quite a rapid rate of fire.... and have not felt as if the Kx is slowing me down. EDIT to ADD - Here are a couple of shots from a club where it was pretty dark - EXIF re-attached. rest of album - link to first pic in series - Picasa Web Albums - UnknownVincent - Last Waltz En... (25 pics mostly on the Kx 3:2 aspect ratio - any 4:3 aspect ratio are from the Canon G10) The second shot was at approx 4 foot-candles or 44lux or EV=4 - this is pretty low. Last edited by UnknownVT; 12-06-2009 at 11:07 AM. Reason: added sample photos

12-06-2009, 12:30 PM	#5
SteveB Veteran Member Join Date: Mar 2007 Location: U.K. Posts: 685	A test in Feb 2010 Computer Shopper calls the Kx AF fast and the Canon T1i (500D) very inaccurate and they had to use manual focus to get any sharp shots. No D300 unfortunately but that's not really a competitor anyway as it costs more. The D90 sounded about the same as the Kx for speed. No figures unfortunately but they are usually quite thorough in their tests and don't seem biased. Other tit-bits...... Kx was the lowest noise. They down-rated the Kx for high premium lens prices and no AF VF points. One big Kx plus was the fact that the kit lens was the sharpest out of Canon, Nikon, Sony and Olympus, and was almost as good as the 50mm primes of the other manufacturers for detail. The T1i was amazingly slow at continuous 0.9fps RAW shooting after the buffer filled, the Kx carries on at 2fps (fast cards). D90 video was not good due to 'lurching' auto exposure and very poor sound, Canon was juddery at 20fps. Kx video was excellent, sound OKish.

12-06-2009, 12:36 PM	#6
SteveB Veteran Member Join Date: Mar 2007 Location: U.K. Posts: 685	Originally posted by WerTicus it can focus in lower light than i can see Can it AF on a black cat in a room lit by one low energy bulb? My K100D can't do this to save its life, even with a Sigma flash assist light. No black cats with white patches allowed, must be black

12-06-2009, 12:53 PM	#7
UnknownVT Veteran Member Join Date: Sep 2007 Location: USA Posts: 1,812	Originally posted by SteveB A test in Feb 2010 Computer Shopper calls the Kx AF fast and the Canon T1i (500D) very inaccurate and they had to use manual focus to get any sharp shots. No D300 unfortunately but that's not really a competitor anyway as it costs more. The D90 sounded about the same as the Kx for speed. No figures unfortunately but they are usually quite thorough in their tests and don't seem biased. Nice to read this - however it seems from the majority of reviews out there that the Canon T1i does not appear to have any focusing issues - and since the T1i is such a popular camera there are numerous reviews out there. However as I said I don't find the Kx slowing me down - and it is certainly more positive and faster than my K100D Originally posted by SteveB Kx was the lowest noise. Again this is general agreement with most findings by users and confirmed with the standardized and consistent test shots on Imaging-Resource - Of all the APS-C sized sensors I feel the Kx has the best high ISO performance - and I am astounded by a dSLR of such a reasonable price - side-by-side comparisons with the test images on the aforementioned Imaging-Resource - the Kx for me was better than the Nikon D300S, D5000 and D90; Canons 7D. T1i Originally posted by SteveB One big Kx plus was the fact that the kit lens was the sharpest out of Canon, Nikon, Sony and Olympus, and was almost as good as the 50mm primes of the other manufacturers for detail. This is how I have always felt about the two basic "kit" lenses (the 50-200 is even better) - they give absolutely nothing away in terms of image quality and AF ability when compared to more expensive lenses. That's always been then reputation of Pentax of having really quality for much less than expected. I was convinced by Popular Photography's reviews of the Samsung versions of those two lenses: Lens Test: Schneider-Kreuznach D-Xenon 18-55mm f/3.5-5.6 AF Lens Test: Schneider-Kreuznach D-Xenon 50-200mm f/4-5.6 AF Pity they did not include their useful SQF table - EDIT to ADD here are scans of the SQF from my copy of the magazine - Last edited by UnknownVT; 12-06-2009 at 01:14 PM. Reason: added scans of SQF tables

12-07-2009, 07:49 AM	#8
bymy141 Veteran Member Join Date: Aug 2007 Photos: Gallery Posts: 1,563	Originally posted by UnknownVT I understand that the Kx has the same AF as the Pentax K7? If so, then "on paper" it is slower than the current equivalent Canon or Nikon - crops from Popular Photography tests one of the very few places that actually test AF at different light levels. As one can see at lower light levels the K7 could take TWICE as long as the Canon or Nikon.... BUT I own and have used the Kx for my shooting which is mainly musicians on stage - and I have found the Kx AF positive and fast enough for my (critical) usage. But I only use the central AF point and always pre-focus - even when shooting a series - I focus on the face/eye hold re-compose then shoot - even doing that I can get quite a rapid rate of fire.... and have not felt as if the Kx is slowing me down. I don't know about test setups versus practical use. However, I've been shooting wild life in darkness, shoulder to shoulder with 450D and 500D users. Combined with a DA*6-250mm my K-7 was allways the fastest to lock focus and the most accurate. If the K-x uses the same AF system, you should not worry...

12-07-2009, 10:42 AM	#9
WerTicus Veteran Member Join Date: Mar 2009 Location: Perth Australia Photos: Albums Posts: 1,514	Originally posted by SteveB Can it AF on a black cat in a room lit by one low energy bulb? My K100D can't do this to save its life, even with a Sigma flash assist light. No black cats with white patches allowed, must be black Not sure, i only tested it on a black space cat flying through a black hole in space.