Is it possible to autofocus correctly with a Pentax?

Rupert · 07-29-2016, 12:04 PM

Originally posted by boriscleto

What's a DPR?

Depraved....Perverted.....and Ridiculed? Just guessing...am I close?

---------- Post added 07-29-16 at 02:09 PM ----------

I want a camera that can AF accurately and quickly on a dark moonless night when I can't even see a damn thing in the viewfinder, and have to guess at the composition?
Reckon the K1 can do that?

**PJ1** · 07-29-2016, 04:17 PM

Originally posted by Rupert

a dark moonless night when I can't even see a damn thing in the viewfinder

Caption - "We can't do it here. He's got a PENTAX!!!"

Rupert · 07-29-2016, 06:39 PM

Originally posted by PJ1

Caption - "We can't do it here. He's got a PENTAX!!!"

mee · 07-29-2016, 07:26 PM

Originally posted by boriscleto

What's a DPR?

Democratic People's Republic.. its a totalitarian regime where if you don't agree with the dear leader's hidden agenda you are mocked and/or silenced.

C_Jones · 07-30-2016, 08:04 AM

Originally posted by clackers

Others have shown cars, bicycles, birds, horses and dogs in action since that regrettable article was published. I posted shots of trail runners the other week with an old K-x and DA55-300 with single spot AF-C.

Now I got the chance to put my Sigma 150-500 onto the K-1, turned on AF-C with simple Auto-33, didn't even use SEL mode - no problems at all at a local flying display, with the planes either on the ground or in the air. I'm a back button focus kinda guy, by the way - just removes one source of user error. The in-flight crops are at 1/800s, f8 and ISO 400.

What you said/experienced is in the category of my evaluation of Pentax AF when I have used it with my K-3II/Sigma 150-500 combination. I have done fast/slow moving sports and wildlife among other things and the AF is effective.

Nice airshow shots.

reeftool · 07-30-2016, 10:36 AM

I've been shooting motorcycle races for years with Pentax cameras. Is the AF perfect? Nope! I miss a few but I also hear the Nikon guy standing next to me cussing a lot. Shooting with a telephoto is especially tricky. Your subject is moving and no matter how good the AF on your camera is, you have to follow your subject very closely. I was doing this with a manual camera long before AF came along so I thought the AF on my K10D was the greatest thing ever invented. I always scratched my head when I heard people bitching about it.

**monochrome** · 07-30-2016, 10:43 AM

Originally posted by reeftool

I've been shooting motorcycle races for years with Pentax cameras. Is the AF perfect? Nope! I miss a few but I also hear the Nikon guy standing next to me cussing a lot. Shooting with a telephoto is especially tricky. Your subject is moving and no matter how good the AF on your camera is, you have to follow your subject very closely. I was doing this with a manual camera long before AF came along so I thought the AF on my K10D was the greatest thing ever invented. I always scratched my head when I heard people bitching about it.

Yes, but see, you are willing to aim the front element of the lens at something. The fact that a Pentax obligates the camera operator to actually do something - to interact with subject and tool, to take control and responsibility - the fact of itself defines the failure of Pentax, in the opinion of The Ph.D.

They're such whiny babies over there.

Volker76 · 07-30-2016, 05:19 PM

Well, I went to a horse racing event today. Shot 200 pics with a cheapo Sigma 70-300 and I am surprised that so many pics came out ok.

Focusing isn't a problem. My inability is.

(in related note, attempted some macros a couple of days ago. Again AF was fine, not the camera's fault that I suck.)

Sterby · 07-31-2016, 02:13 PM

Originally posted by SpecialK

Well, there was only one object, or formation, centered in the frame and by the time focus was achieved it was on the ass end of the plane. Repeatedly.

This sounds more like a back/front-focus problem. Had the same but with front focus on my Sigma 50-500 and the Tammy 70-200 on my K-3 but more prominent on the Sigma. I needed several sessions to dial in the AF adjustment (currently at -3, needing another one to make sure) and the problem even with BIF has improved substantially. I mostly found that the problems I ran into were indeed of my own stupidity, lack of experience or just plain lack of patience to sit down and go through the setups.
On the long lens the simple metering chart is not enough, you need the near infinity subjects to take the test shots. On super telephotos even temperature dilation can affect the AF adjustment, so be sure to take and evaluate your test shots at the beginning of the shoot. You don't have to adust every time but it is nice to keep a mental log of your gear and remedy any problems when they pop up so you don't have to go home with 3000 OOF shots and a heavy headache.

Sterby · 07-31-2016, 02:41 PM

Originally posted by Sterby

This sounds more like a back/front-focus problem...

Adding some extra to the debate, this shot (I hope it uploads) was made with a Sigma APO 400/5.6 MF, that is manual focus only (!!!) lens with some of that famous dust hazing in the focusing elements.
It might not show but the heli was traveling vertically upwards at the speed of sound, we know how these little devil machines with their whirling death blades dance around. I used catch-in-focus but still it was a very low keeper rate. But I got keepers just like this shot.
This whole AF debate sounds stupid, even for my undereducated material sciences and engineering filled head. No PhD though

Why not continue with a much more meaningful debate: How to properly address the optics on our cameras? "Lens"? "Lenses"? "Glass"? "Lense" perhaps?
I say call it "lense" and everyone else who says otherwise is confirmation bias, whatever the heck that means.

SpecialK · 07-31-2016, 03:57 PM

Originally posted by Sterby

This sounds more like a back/front-focus problem

The lens did not have a FF/BF issue. The lens would hunt and stop, or not even hunt. The End.

Sterby · 08-01-2016, 01:17 AM

Did you try sending both in for service? Lots of lenses and bodies are used in the world with that combination and they all work. If either the lens or the body has a defect then it won't work.
My 50-500 does the same when I put on the DA 1.4x TC, even the Tammy gets prone to hunting with the TC. Could be that an optical defect in the lens made the AF sensor signal wonky.
I'm not trying to convince you of anything just curious about your issue.

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07-29-2016, 12:04 PM	#31
Rupert Veteran Member Join Date: Sep 2006 Location: Texas Photos: Gallery \| Albums Posts: 25,123	Originally posted by boriscleto What's a DPR? Depraved....Perverted.....and Ridiculed? Just guessing...am I close? ---------- Post added 07-29-16 at 02:09 PM ---------- I want a camera that can AF accurately and quickly on a dark moonless night when I can't even see a damn thing in the viewfinder, and have to guess at the composition? Reckon the K1 can do that?

07-29-2016, 04:17 PM	#32
PJ1 Loyal Site Supporter Join Date: Jul 2012 Location: Toowoomba, Australia Photos: Gallery \| Albums Posts: 5,484	Originally posted by Rupert a dark moonless night when I can't even see a damn thing in the viewfinder Caption - "We can't do it here. He's got a PENTAX!!!"

07-29-2016, 06:39 PM	#33
Rupert Veteran Member Join Date: Sep 2006 Location: Texas Photos: Gallery \| Albums Posts: 25,123	Originally posted by PJ1 Caption - "We can't do it here. He's got a PENTAX!!!"

07-29-2016, 07:26 PM	#34
mee Veteran Member Join Date: May 2010 Posts: 7,403	Originally posted by boriscleto What's a DPR? Democratic People's Republic.. its a totalitarian regime where if you don't agree with the dear leader's hidden agenda you are mocked and/or silenced.

07-30-2016, 08:04 AM	#35
C_Jones Pentaxian Join Date: Sep 2012 Location: NY Photos: Gallery \| Albums Posts: 6,084	Originally posted by clackers Others have shown cars, bicycles, birds, horses and dogs in action since that regrettable article was published. I posted shots of trail runners the other week with an old K-x and DA55-300 with single spot AF-C. Now I got the chance to put my Sigma 150-500 onto the K-1, turned on AF-C with simple Auto-33, didn't even use SEL mode - no problems at all at a local flying display, with the planes either on the ground or in the air. I'm a back button focus kinda guy, by the way - just removes one source of user error. The in-flight crops are at 1/800s, f8 and ISO 400. What you said/experienced is in the category of my evaluation of Pentax AF when I have used it with my K-3II/Sigma 150-500 combination. I have done fast/slow moving sports and wildlife among other things and the AF is effective. Nice airshow shots.

07-30-2016, 10:36 AM	#36
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,554	I've been shooting motorcycle races for years with Pentax cameras. Is the AF perfect? Nope! I miss a few but I also hear the Nikon guy standing next to me cussing a lot. Shooting with a telephoto is especially tricky. Your subject is moving and no matter how good the AF on your camera is, you have to follow your subject very closely. I was doing this with a manual camera long before AF came along so I thought the AF on my K10D was the greatest thing ever invented. I always scratched my head when I heard people bitching about it.

07-30-2016, 10:43 AM	#37
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	Originally posted by reeftool I've been shooting motorcycle races for years with Pentax cameras. Is the AF perfect? Nope! I miss a few but I also hear the Nikon guy standing next to me cussing a lot. Shooting with a telephoto is especially tricky. Your subject is moving and no matter how good the AF on your camera is, you have to follow your subject very closely. I was doing this with a manual camera long before AF came along so I thought the AF on my K10D was the greatest thing ever invented. I always scratched my head when I heard people bitching about it. Yes, but see, you are willing to aim the front element of the lens at something. The fact that a Pentax obligates the camera operator to actually do something - to interact with subject and tool, to take control and responsibility - the fact of itself defines the failure of Pentax, in the opinion of The Ph.D. They're such whiny babies over there.

07-30-2016, 05:19 PM	#38
Volker76 Senior Member Join Date: Nov 2014 Posts: 211	Well, I went to a horse racing event today. Shot 200 pics with a cheapo Sigma 70-300 and I am surprised that so many pics came out ok. Focusing isn't a problem. My inability is. (in related note, attempted some macros a couple of days ago. Again AF was fine, not the camera's fault that I suck.)

07-31-2016, 02:13 PM	#39
Sterby Senior Member Join Date: Feb 2016 Location: Tarján Photos: Albums Posts: 140	Originally posted by SpecialK Well, there was only one object, or formation, centered in the frame and by the time focus was achieved it was on the ass end of the plane. Repeatedly. This sounds more like a back/front-focus problem. Had the same but with front focus on my Sigma 50-500 and the Tammy 70-200 on my K-3 but more prominent on the Sigma. I needed several sessions to dial in the AF adjustment (currently at -3, needing another one to make sure) and the problem even with BIF has improved substantially. I mostly found that the problems I ran into were indeed of my own stupidity, lack of experience or just plain lack of patience to sit down and go through the setups. On the long lens the simple metering chart is not enough, you need the near infinity subjects to take the test shots. On super telephotos even temperature dilation can affect the AF adjustment, so be sure to take and evaluate your test shots at the beginning of the shoot. You don't have to adust every time but it is nice to keep a mental log of your gear and remedy any problems when they pop up so you don't have to go home with 3000 OOF shots and a heavy headache.

07-31-2016, 03:57 PM	#41
SpecialK Pentaxian Join Date: Dec 2006 Location: So California Photos: Gallery Posts: 16,481	Originally posted by Sterby This sounds more like a back/front-focus problem The lens did not have a FF/BF issue. The lens would hunt and stop, or not even hunt. The End.

08-01-2016, 01:17 AM	#42
Sterby Senior Member Join Date: Feb 2016 Location: Tarján Photos: Albums Posts: 140	Did you try sending both in for service? Lots of lenses and bodies are used in the world with that combination and they all work. If either the lens or the body has a defect then it won't work. My 50-500 does the same when I put on the DA 1.4x TC, even the Tammy gets prone to hunting with the TC. Could be that an optical defect in the lens made the AF sensor signal wonky. I'm not trying to convince you of anything just curious about your issue.