AF is made slow? Or something wrong with my skills?


joycegian

New Member
Apr 11, 2010
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#1
I was at Courts a few days back & took the Canon 550D and just snapped around on Auto Mode & realized that the 550D can just snap snap snap like a machine gun which is = auto focusing is superbly fast.

When I'm on my K-x, I found it extremely irritating that the the lens just keep focusing in & out, in & out then I can shoot that single shot. The next shot, it will have to focus in & out, in & out again then I can shoot my 2nd shot.

K-x users, Is it like that?
Or is there something wrong with my shooting skill?

Oh, BTW, I've tried it on both the Kit Lens 18-55 & FA50.
Focusing is just superbly slow..
And I'm using VF, not LV.
LV is worse, it takes like a min to focus on the right thing.

Especially when I'm mostly taking pictures of my Son...


Another thing, when we look through the VF, are we suppose to lean onto the cushion or keep like an inch & look through the VF.
I wear specs, and whenever I look through the VF, the composition is like that, but then when the picture is taken & I see it through the LV, its not like how I composition it in the VF.
 

pinholecam

Moderator
Staff member
Jul 23, 2007
10,954
91
48
#3
The environment is different. You are trying to take pictures of your son. I presume its indoors?
Moving subject, low lighting = challenge in AF

In the store, the lighting is usually brighter and also there are lots of lighting (displays; overhead lighting, tv sets, etc) that are very bright and serve as points of high contrast for a camera to get easy focus.
You want to compare, bring down your DSLR and compare both on the spot.

LV AF is generally 'hopeless' on all brands. :)

Edit :
Just go to a Sony showroom (the big one at Paragon) if you don't believe. Aim at the camera display for testing cameras which is very well lit, and AF is real fast. Turn around to the dark floor area and try again.... you will see the diff.
 

Last edited:

AlvinOMG

New Member
Jan 2, 2010
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Bkt Timah
#4
If I am not wrong, most of the current DSLRs (except Sony i think) uses contrast detect for AF when LV is in use and contrast detect is definitely slower than the usual "phase detect" used with VF.

Anyway to answer your last question, K-X's VF is 96% coverage and not 100% coverage thus some part of the photo may not appear in the VF but in the photo.
 

fengwei

Moderator
Staff member
Aug 25, 2004
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Queenstown
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#5
Well, yes the AF with Pentax can be a bit slow when the light gets darker, but fast enough when it's bright enough. When taking photos in places like IKEA, I'd suggest you to bear w/ our slower AF speed. But it's not slow to a sense that you can't take good photos at all.
 

Limited

Senior Member
Apr 17, 2008
713
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#6
Courts is a good place to experience cameras. Even without any lens attached
Look at the ad...:bsmilie:

 

ranchy

Senior Member
Jan 11, 2010
2,505
25
48
#7
Yup, the conditions when you are you taking make a difference. Are you taking indoors with low lighting? At the store, it is well lighted, the point of focus is easier. However, the auto focus speed for the canon is much faster than pentax.

When u say the lens focus in and out, think you are focusing on something with low contrast, like a white wall? Or the environment is badly lighted. Or you are focusing too close which is out of the lens focus range? But i dont think should be the factor.

LV AF is generally 'hopeless' on all brands. :)

Edit :
Just go to a Sony showroom (the big one at Paragon) if you don't believe. Aim at the camera display for testing cameras which is very well lit, and AF is real fast. Turn around to the dark floor area and try again.... you will see the diff.
Hmm the sony A330 live view is good leh. Lol. Found it so much better than the k7. :think:
 

darrrrrrrrrr

Senior Member
Sep 19, 2006
3,209
5
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Singapore
#8
I was at Courts a few days back & took the Canon 550D and just snapped around on Auto Mode & realized that the 550D can just snap snap snap like a machine gun which is = auto focusing is superbly fast.

When I'm on my K-x, I found it extremely irritating that the the lens just keep focusing in & out, in & out then I can shoot that single shot. The next shot, it will have to focus in & out, in & out again then I can shoot my 2nd shot.

K-x users, Is it like that?
Or is there something wrong with my shooting skill?

Oh, BTW, I've tried it on both the Kit Lens 18-55 & FA50.
Focusing is just superbly slow..
And I'm using VF, not LV.
LV is worse, it takes like a min to focus on the right thing.

Especially when I'm mostly taking pictures of my Son...


Another thing, when we look through the VF, are we suppose to lean onto the cushion or keep like an inch & look through the VF.
I wear specs, and whenever I look through the VF, the composition is like that, but then when the picture is taken & I see it through the LV, its not like how I composition it in the VF.
When you talk about machine gun I don't think you're referring to the continuous shooting rate right? Anyway the most likely thing is that it's a lot darker indoors than your eyes may lead you to think, so the camera has trouble with autofocus. Perhaps if you take the 550D to the same location it will perform badly as well.

Aiming at high contrast areas helps but beyond a certain point it just doesn't work anymore. In that case, either manual focus or (like FW always suggests) take your kid outdoors. :bsmilie:
 

May 7, 2010
1,028
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0
#9
i think TS was focusing on moving subject in dark areas, well, presumably..

one thing i'm not sure is that why PNS cameras can have such quick contrast detect AF yet dslrs cant.

oh by the way, using non-rechargables strong lithium batteries like energiser ultimate lithium provides a higher voltage, thus will provide faster AF speed as compared to rechargables like eneloops or the likes.

As from my experience with the kx, both 18-55 and 55-300, the AF is fast and accurate, even in darker indoor area, as long as u know where to aim instead of a blank wall/ceiling. My cousin with nikon D80 tried out my 18-55 and said it is extremely fast as compared to his cam, and that tested on eneloops
What surprises me was the 55-300 that it's still manage to focus relatively fast and most important, accurately even it's already pretty dark.
 

eow

Senior Member
Jun 22, 2004
10,063
6
38
#10
among the LV....pentax is the most hopeless...even at ovf Af is never pentax strongest point though Kx is it best camera to date in term of af with the K7
 

ranchy

Senior Member
Jan 11, 2010
2,505
25
48
#11
Well, yes the AF with Pentax can be a bit slow when the light gets darker, but fast enough when it's bright enough. When taking photos in places like IKEA, I'd suggest you to bear w/ our slower AF speed. But it's not slow to a sense that you can't take good photos at all.
Yeah.. its not slow till it cant take good photo. I kinda of like the feel of pentax auto focus, at least i know its working or moving when i half press the shutter. lol :bsmilie: although i would envy when i try other brand which focus so fast. :sticktong
 

ricsal

New Member
Jun 23, 2007
1,549
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#12
Wait la, maybe the next model will be faster. it all takes time.
 

whatjerom

New Member
Jun 12, 2010
266
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Geylang
#13
Sorry, i don't own a k-x now but going to own one soon, just wanna ask, why Pentax's LV is hopeless uh? I don't understand here.. Sorry.. :( Anyone can explain to me?
 

ricsal

New Member
Jun 23, 2007
1,549
0
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#15
Sorry, i don't own a k-x now but going to own one soon, just wanna ask, why Pentax's LV is hopeless uh? I don't understand here.. Sorry.. :( Anyone can explain to me?
All DLSRs brands LV are hopeless. Personally in my opinion, if getting a DSLR is to use LV, better just get a M4/3rd camera,samsung etc. They are better at it.:thumbsup:

Using VF will gives u more kicks to peeping addiction. :bsmilie:
 

night86mare

Deregistered
Aug 25, 2006
25,541
0
0
www.pbase.com
#18
I was at Courts a few days back & took the Canon 550D and just snapped around on Auto Mode & realized that the 550D can just snap snap snap like a machine gun which is = auto focusing is superbly fast.

When I'm on my K-x, I found it extremely irritating that the the lens just keep focusing in & out, in & out then I can shoot that single shot. The next shot, it will have to focus in & out, in & out again then I can shoot my 2nd shot.

K-x users, Is it like that?
Or is there something wrong with my shooting skill?

Oh, BTW, I've tried it on both the Kit Lens 18-55 & FA50.
Focusing is just superbly slow..
And I'm using VF, not LV.
LV is worse, it takes like a min to focus on the right thing.

Especially when I'm mostly taking pictures of my Son...


Another thing, when we look through the VF, are we suppose to lean onto the cushion or keep like an inch & look through the VF.
I wear specs, and whenever I look through the VF, the composition is like that, but then when the picture is taken & I see it through the LV, its not like how I composition it in the VF.
the composition not the same is cos of viewfinder coverage, you will get extra things at the edge, this is unavoidable unless you get 100% viewfinder, which is on k-7 and some other models from other brands.

autofocus of pentax is weaker in low light. i thought k-x should be improved of course, but naturally low light AF of pentax has never been a strong point.
 

pinholecam

Moderator
Staff member
Jul 23, 2007
10,954
91
48
#19
K7 vs 7D AF speed

[vid]ngUcQUchHEU[/vid]
How come never test the K7 in the darken room? No fair leh... :bsmilie:
Pointless test.
Took one of the acknowledged slowest focus 50-135/2.8 compared to other non-equivalent lenses.
At least go borrow a Tokina 50-135/2.8 for gods sake!


Not to say that Pentax AF is top notch, but its certainly good enuff in most cases.
Just go take more pictures.......


BTW, I love the analogy of TOP GUN (its a school/course btw; not a hot shot) ;)
http://en.wikipedia.org/wiki/United_States_Navy_Strike_Fighter_Tactics_Instructor_program
 

Nikkornos

Senior Member
Oct 31, 2008
3,428
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Singapore/Asia
#20
Pentax k-x is an excellent camera. Don't judge it just by the AF.
Nikon with the AFS lens can fail at times in real life, never mind phase or contrast detect mode.

Look at what the k-x offers:
12.4 mega Cmos, film modes, funky holga special effects, cross processing, 10x exposure, trap focus, on-body vibration reduction (you only buy a VR one time, not every time you buy a lens), thousands of old/new Manual Focus lens to fit with Aperture priority, and....

LOW COST.

This camera is only 1/3 the cost of some of my lens. What can you ask for? This is a DREAM camera.... should we complain about slow AF :dunno:

On the Canon, I can show you how slow it is when mounted with certain lens.... it can go yeee---ahhhh-yeee-ahhhh for the whole day and still cannot focus.
 

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