Pentax AF really need fixing

Rupert · 05-18-2011, 08:45 AM

Originally posted by Croc

i went over every picture in that thread and NON of them demonstrates death of urban legend about K5 being soft, I don't think i seen even one picture that is sharp in that whole thread and was shot at f1.4, NOT ONE and the only one shot at f1.4 (old clock) was in fact OUT OF FOCUS by a country mile, so nobody there got results to show for it, how can anyone use that thread as example of pentax good AF is just crazy to me, seriously if you going to set aperture so high where DOF is so massive that you can close my eyes spin the ring at random and still get focus spot on in manual focus on top of that but tell me how on earth does that shows that k5 doesn't have focus issue?
I got 100000+ pictures that are keepers done with pentax with many that freakish sharp but that does NOT change the fact that there is problem with autofocus i just figured out how to deal with it for most the time and in past where i used slower lenses and would just not see the problem BUT there is a problem and your links if anything confirmed what i been saying.

No problem for me with the K5 AF......I have made a minor adjustment 0f +3 on my Bigma that seems to be an improvement, but for 95% of my shooting or more, I have stopped down a little to get the best results from any particular lens.

I'm wondering just how many shooters shoot regularly at f1.4, or even have such a lens, and even further...how many have a f1.4 lens that delivers sharp crisp shots wide open? Few lenses accomplish this feat, and with the K5 and its high ISO it is not necessary except for that extremely shallow DOF. If that is a persons main goal in life, they should be shooting FF and have some very fine glass to go with it. I don't think that is anywhere near the majority of us here.

My wife's Escape won't go where my Jeep will...so, get a Jeep. But the Jeep is not as smooth and quiet....get a Lexus. Seldom does everything you want come in one package. The K5 comes pretty close.......

Best Regards!

krypticide · 05-18-2011, 09:17 AM

Sucks for you, I guess. My K-5 is dead accurate most of the time. Maybe you really should just switch systems if it's really such a big problem.

Sent from my EVO 4G with MIUI

Rupert · 05-18-2011, 02:40 PM

The only Squirrel I think I have ever shot at F 1.4........with the Nokton 58mm. I was very close...see the tiny mosquitoes behind his right ear?
F1.4 is not practical, or even desired for most Squirrel shooting...or I would use it more often than once in a million shots. I think it shocked this little guy?

Regards!
[IMG]

[/IMG]

**Ash** · 05-18-2011, 05:10 PM - **1 Like**

There's in-camera AF fine tuning, then there's lens calibration with the camera - same spectrum, different extents to the AF misfocusing problem.

A lot of testing has been done by end users of the K-5 that wasn't being done for previous models, especially before AF fine tuning became a menu feature in the K20D. And of course as a result, many users are getting unnecessarily disappointed over minute focusing inaccuracies with lenses they wouldn't shoot wide open with at close focusing distances (as with test charts). Notwithstanding the genuine problems seen occasionally with the K-5, I do think it's time for people to just get out there and shoot the way they've always been shooting and review those results.

Despite noticing small flaws in my own K-5 AF system, I rate them as relatively insignificant as it has not stopped me from getting brilliant images from shooting in real world situations. In fact it has improved significantly, particularly as a result of the low-light focusing ability over previous cameras.

Last edited by Ash; 05-18-2011 at 05:16 PM.

WerTicus · 05-19-2011, 07:13 AM

I've just replaced my da40mm and da70mm with a da* 55mm. I'm not certain yet but i think i may regret doing this.

I noticed no problems with the DA limiteds. Everything was fine and dandy so I never even dusted off the focus test chart. I just used them. f2.4 and f2.8 is slow enough that I dont think id see any issues up to + - 5 in real world shooting.

Now with the 55mm not a single shot was in focus, outside at the park nothing was in focus, it was very very obviously badly back focusing (by meters and meters). So went right in and added +5 adjustment, still pretty bad... +8 almost perfect +10... virtually perfect perhaps +11 if available would be better.

However I still dont really feel confident in using the lens wider than f2, its far too easy to miss focus wider than that regardless of the adjustment corrections.

Now I've just done a focus chart test on the lens and found it to be perfect at +6 instead of the +10 outside during the day. This has me worried a bit because its inside at night, under good light (120w halogen) and the focus differs from outside in bright over cast light. I'm going to HAVE to be taking this lens to a wedding soon, so I'll keep this in mind and change the adjustment accordingly and im not going to dare going below f2 maybe f2.5 to be safe.

My camera is still stained so when it goes in to get that fixed after the wedding I'll send it with the DA* and tell them to make it damn well perfect. If the service center cannot do this, then I can say that faster than f2 is no really possible reliably.

WerTicus · 05-19-2011, 07:47 AM

Just done some real world test shooting around the dimmly lit house at f1.8 and its spot on at +6 adjustment, so tomorrow i'll test in the bright sun and see how it goes.

DogLover · 05-19-2011, 07:57 AM

Originally posted by WerTicus

Just done some real world test shooting around the dimmly lit house at f1.8 and its spot on at +6 adjustment, so tomorrow i'll test in the bright sun and see how it goes.

I'd really encourage you to hang in there with the DA*55 as it is such a rewarding lens. Hope you get it to your liking.

jstevewhite · 05-19-2011, 08:02 AM

Originally posted by DogLover

I'd really encourage you to hang in there with the DA*55 as it is such a rewarding lens. Hope you get it to your liking.

I keep debating between the DA* 55, the DA15ltd and the DA70ltd. I've got the 100 2.8 for a long portrait lens, and I've got the Sigma 10-20 for WA, and I've got the FA50 1.4. I keep debating selling the 10-20 and getting the DA15ltd, and selling the FA 50 1.4 and getting the DA* 55 for closer portrait work.

LBA decisions are hard.

DogLover · 05-19-2011, 08:20 AM - **1 Like**

Originally posted by jstevewhite

I keep debating between the DA* 55, the DA15ltd and the DA70ltd. I've got the 100 2.8 for a long portrait lens, and I've got the Sigma 10-20 for WA, and I've got the FA50 1.4. I keep debating selling the 10-20 and getting the DA15ltd, and selling the FA 50 1.4 and getting the DA* 55 for closer portrait work.

LBA decisions are hard.

I have made those same exact 2 decisions at points over the last few years. For me, they turned out to be exactly the right decisions. I find the results I get with the DA15 to be much more pleasing than what I got with the 10-20. That's not a knock on that lens, I just never connected with it the way I almost immediately did with the 15.

With the other, the FA50 just left me wanting, frankly, and it turns out that, indeed, I was wanting a DA*55. Now, I apparently was lucky enough to get an outstanding copy but I still think that mine is the rule, not the exception. I've seen too many other folks posting fine things from this jewel. It was designed by Pentax (by their most accomplished and heralded lens designer) to be a consummate portrait lens, and at this it does excel. But of course, that just means that it's great at a lot of things. I love it.

jstevewhite · 05-19-2011, 08:38 AM

Originally posted by DogLover

I have made those same exact 2 decisions at points over the last few years. For me, they turned out to be exactly the right decisions. I find the results I get with the DA15 to be much more pleasing than what I got with the 10-20. That's not a knock on that lens, I just never connected with it the way I almost immediately did with the 15.

With the other, the FA50 just left me wanting, frankly, and it turns out that, indeed, I was wanting a DA*55. Now, I apparently was lucky enough to get an outstanding copy but I still think that mine is the rule, not the exception. I've seen too many other folks posting fine things from this jewel. It was designed by Pentax (by their most accomplished and heralded lens designer) to be a consummate portrait lens, and at this it does excel. But of course, that just means that it's great at a lot of things. I love it.

Thanks for the advice. I think it sounds very reasonable. +1

WerTicus · 05-19-2011, 09:25 AM

I'll be using the 55 in at least one serious shoot and then I'll know if love it or if i should have kept my da70... in which case i'll just post it back to adorama and swap it for a new da70 i think.

DogLover · 05-19-2011, 09:54 AM

Originally posted by WerTicus

I'll be using the 55 in at least one serious shoot and then I'll know if love it or if i should have kept my da70... in which case i'll just post it back to adorama and swap it for a new da70 i think.

Well, as you're probably already aware, the AF of the DA*55 will be a little slower than the DA70. Not sure what kind of shoot you're doing, but hopefully that won't be a problem for you. To me, that's really the only negative about the 55, and it's no deal-breaker for my use. It's still one heck of a lot faster than MF!

Frogfish · 05-19-2011, 10:43 AM

Originally posted by Eruditass

Focus out to 20 feet with a normal lens and the DoF isn't razor thin...

Some extreme examples with way shallower than what f1.4 would acheive with the brenizer method (all standard lens optical blur, no T/S or post process blurring):

Sharpness from stopping down is another story and I agree.

Gorgeous shots all 4 Sean - but particularly the just wed couple on the bench. Love the background & bokeh.

Frogfish · 05-19-2011, 10:46 AM

Originally posted by Smeggypants

I fond the AF lamp consistent in 1.02 and below. 1.03 it is inconsistent. This is the same on all 3 K-5s I have used

I keep it switched off most of the time anyway ..... nothing like a laser-like green beam distracting your intended victim ... err subject.

Frogfish · 05-19-2011, 10:49 AM

Originally posted by Siegfried

Ash,
Understood, I feel myself a bit confused I haven't met that term before.

Eruditass,
you made my day. I've studied K-5 manual twice (I love reading manuals, honestly) but I missed that feature there.

Zig

To avoid any SD card problems you should reformat after each use anyway (I always do with all my cards) - that solves your problem another way.

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05-18-2011, 08:45 AM	#151
Rupert Veteran Member Join Date: Sep 2006 Location: Texas Photos: Gallery \| Albums Posts: 25,123	Originally posted by Croc i went over every picture in that thread and NON of them demonstrates death of urban legend about K5 being soft, I don't think i seen even one picture that is sharp in that whole thread and was shot at f1.4, NOT ONE and the only one shot at f1.4 (old clock) was in fact OUT OF FOCUS by a country mile, so nobody there got results to show for it, how can anyone use that thread as example of pentax good AF is just crazy to me, seriously if you going to set aperture so high where DOF is so massive that you can close my eyes spin the ring at random and still get focus spot on in manual focus on top of that but tell me how on earth does that shows that k5 doesn't have focus issue? I got 100000+ pictures that are keepers done with pentax with many that freakish sharp but that does NOT change the fact that there is problem with autofocus i just figured out how to deal with it for most the time and in past where i used slower lenses and would just not see the problem BUT there is a problem and your links if anything confirmed what i been saying. No problem for me with the K5 AF......I have made a minor adjustment 0f +3 on my Bigma that seems to be an improvement, but for 95% of my shooting or more, I have stopped down a little to get the best results from any particular lens. I'm wondering just how many shooters shoot regularly at f1.4, or even have such a lens, and even further...how many have a f1.4 lens that delivers sharp crisp shots wide open? Few lenses accomplish this feat, and with the K5 and its high ISO it is not necessary except for that extremely shallow DOF. If that is a persons main goal in life, they should be shooting FF and have some very fine glass to go with it. I don't think that is anywhere near the majority of us here. My wife's Escape won't go where my Jeep will...so, get a Jeep. But the Jeep is not as smooth and quiet....get a Lexus. Seldom does everything you want come in one package. The K5 comes pretty close....... Best Regards!

05-18-2011, 09:17 AM	#152
krypticide Veteran Member Join Date: Dec 2007 Photos: Gallery Posts: 1,079	Sucks for you, I guess. My K-5 is dead accurate most of the time. Maybe you really should just switch systems if it's really such a big problem. Sent from my EVO 4G with MIUI

05-18-2011, 02:40 PM	#153
Rupert Veteran Member Join Date: Sep 2006 Location: Texas Photos: Gallery \| Albums Posts: 25,123	The only Squirrel I think I have ever shot at F 1.4........with the Nokton 58mm. I was very close...see the tiny mosquitoes behind his right ear? F1.4 is not practical, or even desired for most Squirrel shooting...or I would use it more often than once in a million shots. I think it shocked this little guy? Regards! [IMG] [/IMG]

05-18-2011, 05:10 PM - 1 Like	#154
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	There's in-camera AF fine tuning, then there's lens calibration with the camera - same spectrum, different extents to the AF misfocusing problem. A lot of testing has been done by end users of the K-5 that wasn't being done for previous models, especially before AF fine tuning became a menu feature in the K20D. And of course as a result, many users are getting unnecessarily disappointed over minute focusing inaccuracies with lenses they wouldn't shoot wide open with at close focusing distances (as with test charts). Notwithstanding the genuine problems seen occasionally with the K-5, I do think it's time for people to just get out there and shoot the way they've always been shooting and review those results. Despite noticing small flaws in my own K-5 AF system, I rate them as relatively insignificant as it has not stopped me from getting brilliant images from shooting in real world situations. In fact it has improved significantly, particularly as a result of the low-light focusing ability over previous cameras. Last edited by Ash; 05-18-2011 at 05:16 PM.

05-19-2011, 07:13 AM	#155
WerTicus Veteran Member Join Date: Mar 2009 Location: Perth Australia Photos: Albums Posts: 1,514	I've just replaced my da40mm and da70mm with a da* 55mm. I'm not certain yet but i think i may regret doing this. I noticed no problems with the DA limiteds. Everything was fine and dandy so I never even dusted off the focus test chart. I just used them. f2.4 and f2.8 is slow enough that I dont think id see any issues up to + - 5 in real world shooting. Now with the 55mm not a single shot was in focus, outside at the park nothing was in focus, it was very very obviously badly back focusing (by meters and meters). So went right in and added +5 adjustment, still pretty bad... +8 almost perfect +10... virtually perfect perhaps +11 if available would be better. However I still dont really feel confident in using the lens wider than f2, its far too easy to miss focus wider than that regardless of the adjustment corrections. Now I've just done a focus chart test on the lens and found it to be perfect at +6 instead of the +10 outside during the day. This has me worried a bit because its inside at night, under good light (120w halogen) and the focus differs from outside in bright over cast light. I'm going to HAVE to be taking this lens to a wedding soon, so I'll keep this in mind and change the adjustment accordingly and im not going to dare going below f2 maybe f2.5 to be safe. My camera is still stained so when it goes in to get that fixed after the wedding I'll send it with the DA* and tell them to make it damn well perfect. If the service center cannot do this, then I can say that faster than f2 is no really possible reliably.

05-19-2011, 07:47 AM	#156
WerTicus Veteran Member Join Date: Mar 2009 Location: Perth Australia Photos: Albums Posts: 1,514	Just done some real world test shooting around the dimmly lit house at f1.8 and its spot on at +6 adjustment, so tomorrow i'll test in the bright sun and see how it goes.

05-19-2011, 07:57 AM	#157
DogLover Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 2,054	Originally posted by WerTicus Just done some real world test shooting around the dimmly lit house at f1.8 and its spot on at +6 adjustment, so tomorrow i'll test in the bright sun and see how it goes. I'd really encourage you to hang in there with the DA*55 as it is such a rewarding lens. Hope you get it to your liking.

05-19-2011, 08:02 AM	#158
jstevewhite Veteran Member Join Date: Mar 2009 Location: Midwest Photos: Gallery Posts: 1,407	Originally posted by DogLover I'd really encourage you to hang in there with the DA55 as it is such a rewarding lens. Hope you get it to your liking. I keep debating between the DA 55, the DA15ltd and the DA70ltd. I've got the 100 2.8 for a long portrait lens, and I've got the Sigma 10-20 for WA, and I've got the FA50 1.4. I keep debating selling the 10-20 and getting the DA15ltd, and selling the FA 50 1.4 and getting the DA* 55 for closer portrait work. LBA decisions are hard.

05-19-2011, 08:20 AM - 1 Like	#159
DogLover Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 2,054	Originally posted by jstevewhite I keep debating between the DA* 55, the DA15ltd and the DA70ltd. I've got the 100 2.8 for a long portrait lens, and I've got the Sigma 10-20 for WA, and I've got the FA50 1.4. I keep debating selling the 10-20 and getting the DA15ltd, and selling the FA 50 1.4 and getting the DA* 55 for closer portrait work. LBA decisions are hard. I have made those same exact 2 decisions at points over the last few years. For me, they turned out to be exactly the right decisions. I find the results I get with the DA15 to be much more pleasing than what I got with the 10-20. That's not a knock on that lens, I just never connected with it the way I almost immediately did with the 15. With the other, the FA50 just left me wanting, frankly, and it turns out that, indeed, I was wanting a DA*55. Now, I apparently was lucky enough to get an outstanding copy but I still think that mine is the rule, not the exception. I've seen too many other folks posting fine things from this jewel. It was designed by Pentax (by their most accomplished and heralded lens designer) to be a consummate portrait lens, and at this it does excel. But of course, that just means that it's great at a lot of things. I love it.

05-19-2011, 08:38 AM	#160
jstevewhite Veteran Member Join Date: Mar 2009 Location: Midwest Photos: Gallery Posts: 1,407	Originally posted by DogLover I have made those same exact 2 decisions at points over the last few years. For me, they turned out to be exactly the right decisions. I find the results I get with the DA15 to be much more pleasing than what I got with the 10-20. That's not a knock on that lens, I just never connected with it the way I almost immediately did with the 15. With the other, the FA50 just left me wanting, frankly, and it turns out that, indeed, I was wanting a DA*55. Now, I apparently was lucky enough to get an outstanding copy but I still think that mine is the rule, not the exception. I've seen too many other folks posting fine things from this jewel. It was designed by Pentax (by their most accomplished and heralded lens designer) to be a consummate portrait lens, and at this it does excel. But of course, that just means that it's great at a lot of things. I love it. Thanks for the advice. I think it sounds very reasonable. +1

05-19-2011, 09:25 AM	#161
WerTicus Veteran Member Join Date: Mar 2009 Location: Perth Australia Photos: Albums Posts: 1,514	I'll be using the 55 in at least one serious shoot and then I'll know if love it or if i should have kept my da70... in which case i'll just post it back to adorama and swap it for a new da70 i think.

05-19-2011, 09:54 AM	#162
DogLover Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 2,054	Originally posted by WerTicus I'll be using the 55 in at least one serious shoot and then I'll know if love it or if i should have kept my da70... in which case i'll just post it back to adorama and swap it for a new da70 i think. Well, as you're probably already aware, the AF of the DA*55 will be a little slower than the DA70. Not sure what kind of shoot you're doing, but hopefully that won't be a problem for you. To me, that's really the only negative about the 55, and it's no deal-breaker for my use. It's still one heck of a lot faster than MF!

05-19-2011, 10:43 AM	#163
Frogfish Veteran Member Join Date: Dec 2009 Location: Shanghai Posts: 4,490	Originally posted by Eruditass Focus out to 20 feet with a normal lens and the DoF isn't razor thin... Some extreme examples with way shallower than what f1.4 would acheive with the brenizer method (all standard lens optical blur, no T/S or post process blurring): Sharpness from stopping down is another story and I agree. Gorgeous shots all 4 Sean - but particularly the just wed couple on the bench. Love the background & bokeh.

05-19-2011, 10:46 AM	#164
Frogfish Veteran Member Join Date: Dec 2009 Location: Shanghai Posts: 4,490	Originally posted by Smeggypants I fond the AF lamp consistent in 1.02 and below. 1.03 it is inconsistent. This is the same on all 3 K-5s I have used I keep it switched off most of the time anyway ..... nothing like a laser-like green beam distracting your intended victim ... err subject.

05-19-2011, 10:49 AM	#165
Frogfish Veteran Member Join Date: Dec 2009 Location: Shanghai Posts: 4,490	Originally posted by Siegfried Ash, Understood, I feel myself a bit confused I haven't met that term before. Eruditass, you made my day. I've studied K-5 manual twice (I love reading manuals, honestly) but I missed that feature there. Zig To avoid any SD card problems you should reformat after each use anyway (I always do with all my cards) - that solves your problem another way.