Why do Pentax lag with autofocus?


johnriley

Link Posted 27/01/2013 - 20:16
I'm no expert at wildlife, but have been practising with bird photography and various lenses.

Where focusing is difficult I would maybe focus on the distance involved, perhaps on a tree or whatever, and then just hold that point and capture the bird at the same distance. Or maybe use manual focusing - again it needs practice but photographers managed very well for a long time.

I leave the focusing on centre spot and work with practising with that. It gets better as we go and although there's no chance every shot will be a winner they are generally getting better. I practise wih the equipment I've got and don't fret about the equipment I haven't got.
Best regards, John

NeilP

Link Posted 27/01/2013 - 20:23
After recently trying and failing to focus on some flying Black headed gulls in decent light, I've decided the K-5 + D*300mm just inst up to action shots. Its fine for birds like red kites and a marsh harriers which fly slower, if they are not to close, but the AF speed and tracking cant track faster bird or slower ones that are too close sadly.
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Father Ted

Link Posted 27/01/2013 - 20:42
Could, (and I'll admit that I don't know), "Catch in focus" be an option for the OP. I use this with manual lenses, will this work with AF lenses, but with camera in MF mode?
Getting there! Thanks to you guys

Pentax K10d, *istDL, Kit lens ( 18-55mm ), 50mm f1.7 lens, Tamron 70-300mm lens, Prinzflex 70-162 manual lens, Various old flashes.

milamber

Link Posted 27/01/2013 - 20:57
Father Ted wrote:
Could, (and I'll admit that I don't know), "Catch in focus" be an option for the OP. I use this with manual lenses, will this work with AF lenses, but with camera in MF mode?

Doesn't work with AF lenses - camera body needs to be in AF. I guess you could perhaps mask the AF contacts and force it work, but probably not worth the hassle. Catch in focus works great for macro, but I've never had much success with a distant object. Mind you, that might just be me...
Last Edited by milamber on 27/01/2013 - 21:00

Frogfish

Link Posted 27/01/2013 - 21:05
NeilP wrote:
After recently trying and failing to focus on some flying Black headed gulls in decent light, I've decided the K-5 + D*300mm just inst up to action shots. Its fine for birds like red kites and a marsh harriers which fly slower, if they are not to close, but the AF speed and tracking cant track faster bird or slower ones that are too close sadly.

Neil. Gulls shouldn't be difficult, they are large and relatively slow moving. It's possible there is a problem with your technique or settings. Can you tell us how you hold your camera, whether you use a tripod/monopod and the settings you generally use for bird photography ?
I used the K5 and DA*300 for 2 years (with and without the AFA x1.7) and found it very good on larger birds, it was on smaller birds with frenetic feet, or flushed birds, where it had difficulty. In all cases a degree of anticipation is required though.

Here are some samples all with the K5 + DA*300









http://frogfish.smugmug.com/ Pentax. Pentax DA*300/4, Cosina 55/1.2, Lens Baby Composer Pro & Edge 80, AFA x1.7, Metz 50 af1.
Nikon. D800. D600. Sigma 500/4.5, Nikon 300/2.8 VRII, Sigma 120-300/2.8, Zeiss Distagon ZF2 21/2.8, Zeiss Distagon ZF2 35/2.0, Sigma 50/1.4, Nikkor 85/1.8, Nikon TC20EIII, Nikon TC14EII, Kenko x1.4, Sigma 2.0

Frogfish

Link Posted 27/01/2013 - 21:20
dcweather wrote:
As the OP who has now having seen the result from Nikon 300D shot compared to my failed one could one of the experts suggest an improved technique or settings for me. I was, incidentally going from being focused on the ducks to them following take off so there wasn't a massive change in focal distance. My camera would still have been on AF centre spot. WOuld I be better off with lots of focal points and the 'C' setting. This was with DA*300 and K-30 by the way.
Thanks, Dave

There is the potential, if you use your shutter release button for both focusing and releasing the shutter (it's default postion), for losing focus at the critical moment or failing to lock on because you have the 'do not fire unless in focus" (focus priority) setting enabled (again that's the default).

If you remap your focusing to the AF-S button and leave the firing of the shutter to the shutter release button, plus change the setting to shutter priority instead of focus priority, then the shutter will fire independently of the focusing button (now AF-S) and you will get more shots because the camera is not waiting for focus confirmation - which is sometimes the case that even though for a fraction of a second you had the bird in focus the focus confirmation could ignore this because you lost focus again. This allied to burst mode should give you more keepers.
http://frogfish.smugmug.com/ Pentax. Pentax DA*300/4, Cosina 55/1.2, Lens Baby Composer Pro & Edge 80, AFA x1.7, Metz 50 af1.
Nikon. D800. D600. Sigma 500/4.5, Nikon 300/2.8 VRII, Sigma 120-300/2.8, Zeiss Distagon ZF2 21/2.8, Zeiss Distagon ZF2 35/2.0, Sigma 50/1.4, Nikkor 85/1.8, Nikon TC20EIII, Nikon TC14EII, Kenko x1.4, Sigma 2.0
Last Edited by Frogfish on 27/01/2013 - 21:21

ronniemac

Link Posted 27/01/2013 - 21:36
I was out shooting ducks today with the K-5 and 55-300. On the few occasions when the lens focus hunted, I gave the manual ring a quick turn and the auto picked up on this and nailed the focus. I know Pentax with some lenses (the 55-300 especially) are not fantastic at focusing in low light, but I find that with a little assistance (and practice), it usually gets there.

Blythman

Link Posted 27/01/2013 - 21:37
dcweather wrote:
As the OP who has now having seen the result from Nikon 300D shot compared to my failed one could one of the experts suggest an improved technique or settings for me. I was, incidentally going from being focused on the ducks to them following take off so there wasn't a massive change in focal distance. My camera would still have been on AF centre spot. WOuld I be better off with lots of focal points and the 'C' setting. This was with DA*300 and K-30 by the way.
Thanks, Dave

Dave, in all likelihood you did nothing wrong.

A couple of examples which disappointed me the most because of the birds involved
1.....I was with both a Canon shooter and a Nikon shooter in late summer photographing a cuckoo. I got some great shots and was within 6 yards of it in the open. However it took off from a post and flew to another about 12-15 yards away. Both the other guys got fantastic in flight shots. I got a blur.

2.....Summer before I had my best views of a kingfisher. It even landed on the window ledge of the hide within 4 feet of me for a couple of seconds. Just before then it had been on a perch about 5 yards away, when it lifted, moved forward to about 3 yards. It hovered there for a second or two before diving for a fish. I've got a full frame abstract blue and orange picture.

After the cuckoo I thought very hard about selling up and was actively looking for a 7D and a Sigma 120-300 f2.8.

After much thought I decided to stick with Pentax because I want to photograph more than just wildlife and the K5 in my opinion is a better all round camera than the 7D. One example of that is my mate who takes fantastic wildlife images with his Canon 600mm f4 and 1.5 converter reckons the 7D is crap above ISO 800.
Alan


PPG
Flickr

Frogfish

Link Posted 27/01/2013 - 21:42
Blythman wrote:
One example of that is my mate who takes fantastic wildlife images with his Canon 600mm f4 and 1.5 converter reckons the 7D is crap above ISO 800.

If I had a US$10,000 600/4 I wouldn't be shooting with a 7D
http://frogfish.smugmug.com/ Pentax. Pentax DA*300/4, Cosina 55/1.2, Lens Baby Composer Pro & Edge 80, AFA x1.7, Metz 50 af1.
Nikon. D800. D600. Sigma 500/4.5, Nikon 300/2.8 VRII, Sigma 120-300/2.8, Zeiss Distagon ZF2 21/2.8, Zeiss Distagon ZF2 35/2.0, Sigma 50/1.4, Nikkor 85/1.8, Nikon TC20EIII, Nikon TC14EII, Kenko x1.4, Sigma 2.0

Blythman

Link Posted 27/01/2013 - 21:54
Frogfish wrote:
Blythman wrote:
One example of that is my mate who takes fantastic wildlife images with his Canon 600mm f4 and 1.5 converter reckons the 7D is crap above ISO 800.

If I had a US$10,000 600/4 I wouldn't be shooting with a 7D

Would you rather use his 5DMkII or his 1D MkIV?
Alan


PPG
Flickr

K10D

Link Posted 27/01/2013 - 23:05
Frogfish wrote:
Blythman wrote:
One example of that is my mate who takes fantastic wildlife images with his Canon 600mm f4 and 1.5 converter reckons the 7D is crap above ISO 800.

If I had a US$10,000 600/4 I wouldn't be shooting with a 7D

A very positive ditto.

Best regards

dcweather

Link Posted 28/01/2013 - 00:59
Frogfish wrote:
dcweather wrote:
As the OP who has now having seen the result from Nikon 300D shot compared to my failed one could one of the experts suggest an improved technique or settings for me. I was, incidentally going from being focused on the ducks to them following take off so there wasn't a massive change in focal distance. My camera would still have been on AF centre spot. WOuld I be better off with lots of focal points and the 'C' setting. This was with DA*300 and K-30 by the way.
Thanks, Dave

There is the potential, if you use your shutter release button for both focusing and releasing the shutter (it's default postion), for losing focus at the critical moment or failing to lock on because you have the 'do not fire unless in focus" (focus priority) setting enabled (again that's the default).

If you remap your focusing to the AF-S button and leave the firing of the shutter to the shutter release button, plus change the setting to shutter priority instead of focus priority, then the shutter will fire independently of the focusing button (now AF-S) and you will get more shots because the camera is not waiting for focus confirmation - which is sometimes the case that even though for a fraction of a second you had the bird in focus the focus confirmation could ignore this because you lost focus again. This allied to burst mode should give you more keepers.

--------------------------------
Unfortunately I already do all of the above!
Dave

dcweather

Link Posted 28/01/2013 - 01:12
I think, judging by the responses I may have mislead some or perhaps they have mis-interpreted my question. Initially it was why are Pentax behind the game in this area. In the birding world it is generally accepted that Nikon are superior for BIF shots.I think it is fair to say Neil and myself are not beginners and our galleries show a reasonable level of accomplishment in bird and wildlife photography. Yes I can get BIF in focus and a couple of posts infer that my settings are good. I just get a low hit rate, as does Neil, when birds at say mid-distance appear and you have to point and pan and get it right in say 3-4 sec window. And I have seen many far less accomplished Nikon owners succeed where I have failed.
Typical settings (and of course they vary with situations) for me would be burst mode, centre spot focus point AF, not C, shutter priority release and rear button focus not shutter release.If it was pre-planned against the sky I would probably go to F* to get a bit more latitude in DOF and probably add about +1EV and try and keep shutter speed min of 1/500th. Of course in the real world of nature things don't always work out.

Smeggypants

Link Posted 28/01/2013 - 02:42
dcweather wrote:
I think, judging by the responses I may have mislead some or perhaps they have mis-interpreted my question. Initially it was why are Pentax behind the game in this area. In the birding world it is generally accepted that Nikon are superior for BIF shots.I think it is fair to say Neil and myself are not beginners and our galleries show a reasonable level of accomplishment in bird and wildlife photography. Yes I can get BIF in focus and a couple of posts infer that my settings are good. I just get a low hit rate, as does Neil, when birds at say mid-distance appear and you have to point and pan and get it right in say 3-4 sec window. And I have seen many far less accomplished Nikon owners succeed where I have failed.
Typical settings (and of course they vary with situations) for me would be burst mode, centre spot focus point AF, not C, shutter priority release and rear button focus not shutter release.If it was pre-planned against the sky I would probably go to F* to get a bit more latitude in DOF and probably add about +1EV and try and keep shutter speed min of 1/500th. Of course in the real world of nature things don't always work out.

It can only be down to neglect of AF performance as a priority. It's one area where Pentax need to raise their game considerably to get more inroads into the pro-market where shots can't be missed and the job needs to get done. Sports, papparazi, gigs and so on.

As a hobbyist people shooter I would also like a much more response and accurate AF.
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283

Frogfish

Link Posted 28/01/2013 - 07:50
dcweather wrote:

Unfortunately I already do all of the above!
Dave

Ouch ! Nothing else that I can suggest then other than the obvious.
http://frogfish.smugmug.com/ Pentax. Pentax DA*300/4, Cosina 55/1.2, Lens Baby Composer Pro & Edge 80, AFA x1.7, Metz 50 af1.
Nikon. D800. D600. Sigma 500/4.5, Nikon 300/2.8 VRII, Sigma 120-300/2.8, Zeiss Distagon ZF2 21/2.8, Zeiss Distagon ZF2 35/2.0, Sigma 50/1.4, Nikkor 85/1.8, Nikon TC20EIII, Nikon TC14EII, Kenko x1.4, Sigma 2.0
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