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Pentax K5 AF

hobbsr

New member
Hi All,

I have seen some wonderful examples taken with the new Pentax k5 and so I decided to get a test unit and some lens. I was mainly shooting Nikon D3's and wanted to find a small body and a set of small primes.

I do have a little soft spot for Pentax and have tried the K7 but just found too many aspects that in my opinion were not ready for professional use.

So I have the k5 and 35 2.4, 70 ltd and 100mm WR. What I have found is a real mix bag of AF performance, as in just the focus area not where I aimed! I have tried looking at the images to see if it is front or back focus, I have also tired to do some micro adjustments per lens. The end result is that a large % of images are not not in focus. Also the write speed for RAW is pretty slow.

Can anyone advise the best setup or if this is the nature of the beast? I am using the single AF point in Aperture mode in single shot mode.

Regards
 

scho

Well-known member
Hi All,

I have seen some wonderful examples taken with the new Pentax k5 and so I decided to get a test unit and some lens. I was mainly shooting Nikon D3's and wanted to find a small body and a set of small primes.

I do have a little soft spot for Pentax and have tried the K7 but just found too many aspects that in my opinion were not ready for professional use.

So I have the k5 and 35 2.4, 70 ltd and 100mm WR. What I have found is a real mix bag of AF performance, as in just the focus area not where I aimed! I have tried looking at the images to see if it is front or back focus, I have also tired to do some micro adjustments per lens. The end result is that a large % of images are not not in focus. Also the write speed for RAW is pretty slow.

Can anyone advise the best setup or if this is the nature of the beast? I am using the single AF point in Aperture mode in single shot mode.

Regards
See the thread below this one and earlier posts dealing with AF issues. Front focusing in dim, incandescent lighting seems to be the primary AF issue. I have not had any AF problems in daylight or brighter indoor lighting.
 

ptomsu

Workshop Member
Hi All,

I have seen some wonderful examples taken with the new Pentax k5 and so I decided to get a test unit and some lens. I was mainly shooting Nikon D3's and wanted to find a small body and a set of small primes.

I do have a little soft spot for Pentax and have tried the K7 but just found too many aspects that in my opinion were not ready for professional use.

So I have the k5 and 35 2.4, 70 ltd and 100mm WR. What I have found is a real mix bag of AF performance, as in just the focus area not where I aimed! I have tried looking at the images to see if it is front or back focus, I have also tired to do some micro adjustments per lens. The end result is that a large % of images are not not in focus. Also the write speed for RAW is pretty slow.

Can anyone advise the best setup or if this is the nature of the beast? I am using the single AF point in Aperture mode in single shot mode.

Regards
I had exactly the same issue with my K5 and my 16-55 and DA70. I did AF fine adjust and still then it delivered not consistent results, not even in good light.

And I had done the firmeware update!

Not sure if it was my sample or it is a general issue with the K5 AF, as some here in the forum seem to be totally satisfied with the K5.

But coming from the D3S (I come from D700) it is really hard to find an equivalent AF in any respect.

I sent my Pentax bak and am happy now with the GH2 as small DSLR.
 
@ptomsu "I had exactly the same issue with my K5 and my 16-55 and DA70. I did AF fine adjust and still then it delivered not consistent results, not even in good light."
I had also the same issue with the 16/50 f:2.8 only, I sent it back and now after it has been fixed it is as fine as all the other lens I have (even il low light at 2800 °K).
Certainly as I understand there is an issue with the AF in low light but apparently does not affect all the bodies.
 

ptomsu

Workshop Member
@ptomsu "I had exactly the same issue with my K5 and my 16-55 and DA70. I did AF fine adjust and still then it delivered not consistent results, not even in good light."
I had also the same issue with the 16/50 f:2.8 only, I sent it back and now after it has been fixed it is as fine as all the other lens I have (even il low light at 2800 °K).
Certainly as I understand there is an issue with the AF in low light but apparently does not affect all the bodies.
It obviously is a pretty big issue with Pentax. Because there are (too) many complaints. Which is (was) enough for me to stop further investing in that system.
 

hobbsr

New member
Well, I need to take the test kit back tomorrow and spent more time over the weekend to try and figure out what I think of the K5.

In many ways it is a shame the experience I have had. Out of all the system it is hard to find well build kit these days of plastic stuff! I love the solid feel and the metal lens. The size it great also, too many days with the D3 and large lens that just announce that the photographer is here!

So in the end the AF is a bit of a show stopper for me. It seems that the worse lens was the 100mm WR, mixed results with the 70 2.4 and the best results from the 35 ltd. I tired all manner of AF adjustments and test and the bottom line is I just can't find a consistency to the overall performance. In other words it hits fine sometimes but not all the time and other times not at all!

I don't have enough time to second guess the AF and need to trust my system and at this stage I can't say that is the case with the wonderful k5. As I said at the start what a shame as there are so many great things to like about it and pentax, size, cost and build.

Cheers
 

raist3d

Well-known member
I have to say I must corroborate your observations. I have only two lenses (two primes). The Da 21mm and the DA 70mm. Of the two the DA 70 is the one giving me some issues. Now, I have noticed some things that do help:

- I have my DA 70 at -4 adjust. But like you, while I have found this helps, I have found a degree of unpredictability still.
- I am noticing that in order for the AF to work as I expect, the object needs to feel what seems to be a square around the "led square" of 3x diameter. By this I mean stack 3 squares horizontally and vertically with their center being the square that lights up as a led and that's like the area where the focus will pick up. To be honest, more like 70-80% of the "black line rectangle" that shows on the view finder which is quite a huge area that fills that much, the camera seems to focus better with this lens.

I have mixed feelings. On one end the shadow range and total DR are fantastic. I have been able to really massage some shots in ways I haven't been able to do before and you get this very rich black/tones/etc. On the other, like you, this AF sort of makes me feel not so confident when using it.

Now, I am seeing that I can actually manually focus with this camera. It's a tad hard but not impossible as I have seen with most DSLR's. On that end that doesn't bug me much but I can't see myself shooting a wedding where I manually focus every single shot (maybe I could get to the point that I could do most).

All I am saying is also in daylight. There is definitively an issue with tungsten low light in which the camera clearly front focuses.

There is yet a 2nd issue I am seeing though maybe this one is a much more subtle. I notice with these primes that there's some purple fringing- I think I read some review that noted that they didn't quite happen with the K-7 so apparently it's a sony sensor micro lens interaction thing too. As you close the aperture that goes away, I would definitively not be surprised by say the DA70 at F2.4 giving me some. But seems like sometimes the entire image seems just this very little notch "shifted" on that end, so that the overall image color gets a bit of red/cyan cast (very very subtle though).

When I tried the DA * gold standard zoom I got the impression that doesn't happen. Makes me wonder if the pancake primes are "really good for what they are" but have this issue wide open and how other primes behave. I also notice that in softer light a lot of this doesn't happen and it's all much the better. Also this is much more so for the DA 70 than the DA 21.

Anyhow, I understand Pentax is working on the tungsten light fix, I hope they fix their AF a bit. But given the AF points are much bigger it seems than other cameras (at least the Olympus), seems like some of this will boil down to getting bigger subjects on the view finder before you can AF accurately.

At least the live view AF is reasonably fast and spot on, but yeah.

- Raist
 

jonoslack

Active member
HI There
There really is obviously more here than meets the eye. Like Carl I've had no issues focusing in good light (other than that some lenses need a little adjustment). To be honest, I've not really seen the tungsten light issue either, although I'm quite aware that it does exist, and I suspect that if I bothered I could find it too.

The 100 macro I could criticise for it's noisy focusing, and the time it takes to go from close to far . . . . but I've had no issue with out of focus images, or with CA.

However, I DO have CA issues with the 18-135 zoom, a lens which otherwise seems to perform so much better than one could expect (it really is sharp, and it focuses very fast and accurately). It occurs in high contrast areas, more at the corners, but right across the frame and at all apertures. Of course, these days it's really easy to fix - ten seconds at most - but it would be much better if it were not there.

With it's brand new focusing system, and suddenly high sales, I think it's worth giving Pentax a little leeway to sort these issues out, and I'm hoping for a firmware update to solve the problems - I'd hope that the OP might keep his eyes open and consider trying the camera again in a few months/weeks after the firmware upgrade.

For me, it takes consistently good pictures, and I'm not getting a high rate of out of focus images - no higher than any other camera. I'm sure these things need to be fixed - and to be talked about, but for me at least, the fantastic DR and high ISO together with the small size, lovely ergonomics and the convenient 18-135 make the camera worth persevering with.
 

hobbsr

New member
Update,

I have taken the kit back and they are having the tech look at the body and lens and hope to have it back by Wednesday.

I did also happen to be given a Canon 5D MII with a ZE 35 f2 lens, I use to shoot Canon when I start my professional career and then switched to Nikon after just too many QA issues with lens! Seemed to always be at CPS. Anyway it has been a while since I have shot anything on a Canon body and to my surprise the results shooting manual focus with the 35 wide open are great!

I need to select for digital system so some tough choices ahead.

Cheers
 

Sapphie

Member
Has anyone had to apply any AF adjustments to their 18-135?

I had my K5+18-55 replaced by a K5+18-135 as I wasn't happy with the focus, and I am also referring to day time shots.

With what little chance I have had (2 weekends, one a wash-out) to test out the replacement so far it does seem better. In both cases though they seemed worse when using the lens at the long end. Eg this weekend a nice tree trunk with some coloured lichen etc. I am not sure if I even had it at the long extreme but it was close. Now I know a tree trunk curves but the bit in the middle directly in front of the lens ought to be 'in focus'. It wasn't. Aperture setting was f6.7. Maybe it was camera shake, I dunno. Again, though, just one example, others mostly fine. Maybe I need to realise that a shot with a telephoto at close quarters has less DOF and that I should have increased the aperture?

With CA, I think I have seen that too - what's the best way to remove it with LR 3?

I have also seem some vignetting in the middle of the range at smallish apertures.

Lee
 

MPK2010

New member
I don't use the camera indoors but my experience outdoors in low light has been pretty consistent since my first post on the camera in November -- with phase detect I miss a non-trivial fraction of shots. Because I shot with the GF1 for quite a while and am used to live view/LCD framing, I generally use live view at night to avoid issues. But I would prefer eye-level so I hope they fix it.

Considering the camera's positives, the likelihood that Pentax will fix the issue, and the other weatherproof options out there, I'm not thinking of selling at this point. Of course, for me this is a bad-weather camera rather than my main camera.

The longer-term issue for me is the camera is still larger than what I'd like for a weatherproof back-up. But so far there's no weatherproof mirrorless, much less with a sensor like this. And the IQ at low ISO is very good. And it's a such a good match for the 31.
 

Paratom

Well-known member
Today I will get a new K5, because my other one had the stain thing goin on.
I also had experienced some (unacceptable) focus problems so I am curious if my new K5 will perform better/good as soon as I get an idea.

I want to like this camera but it has to work reliably.
2 things where I see the critical point:
1) AF has to be precise
2) zoom lenses; I badly would want a 16-50/2.8 which works very good. The one I once had was soft at f2.8. The kit zoom is the worst I have ever experiences (the m4/3 Pana Kit zooms is much much better); the 17-70/4.0 feels cheap and wobly for its price. Then there is the 18-135, but I am not sure if I want such a long range/slowish lens.
The primes are very nice except the 15 which needs to be stopped down.
Most primes are not weather seeled.
The 50-135/2.8 is very nice though. If justthat 16-50 was better/less sample variation. The 35Macro is the most solid/reliable lens IMO.
So I am still debating myself if I shall keep the Pentax or keep my Nikon stuff as flexible DSLR.
Will report when I have checked out the new body.
 

Sapphie

Member
One thing I am learning from this is never to buy new kit at this time of year! There aren't enough good weather, daylight, non-work hours to test it out!

As I suggested earlier, most of the shots that I have not been so happy with, sharpness wise, have been taken at the long end of the zoom, though I did have some on my first body with the 43mm ltd.

My tree trunk shot as at about 100mm, so not quite at 135 full extension. The shutter speed was 1/1000th sec and the aperture f6.7. I think the ISO must have been quite high as a result, maybe 800 or 1600. Nowhere on the trunk seems sharp. It is not *wildly* out of focus but it isn't what I would call sharp.

The centre focus point couldn't have missed the target as the tree was occupying most of the frame and anyway the background is correctly very out of focus.

I guess the first thing I need to do is check my lens for back/front focus.

Then I need to check my technique. You wouldn't think camera shake would be an issue at that speed would you, but it's a possibility? Maybe I am 'stabbing' the shutter release downwards too much ...

I do tend to 'dither' a bit before taking a shot sometimes. E.g. line up, aim, focus and just wait a while, sort of making sure I am steady I guess. What happens with the SR after it has stabalised if you wait a few seconds before taking the shot? Does it get fooled in any way or shouldn't it matter?

I do wonder sometimes if I get better results from something like the Panny G1 using the articulated screen as a WLF, holding the camera close to my body, just a feeling sometimes that it is easier to keep steady, even when using the EVF. Maybe it's because there is never any mirror blackout with these cameras.

Anyway, I have hardly had enough time with my 2nd body (+ 18-135) to be sure so hope to out some more at the weekend.

Lee
 

Paratom

Well-known member
I have to say after giving my new K5 a testrun I am still not totally convinced about the AF. Sometimes it seems to work fine and sometimes slightly off even in good daylight (I havent figured out if it depends on the distance).
Many images I get lack the latest sharpness even with good lenses.
I really like the color and filmlike look though.
Frankly I really starting to not like all this testing, checking each and every lens etc etc to be able to have a reliable equipment.
If I could pay 100 € extra for each lens and therefore get a reliable tested lens and same for the body I would happyly pay that money.
 

jonoslack

Active member
I have to say after giving my new K5 a testrun I am still not totally convinced about the AF. Sometimes it seems to work fine and sometimes slightly off even in good daylight (I havent figured out if it depends on the distance).
Many images I get lack the latest sharpness even with good lenses.
I really like the color and filmlike look though.
Frankly I really starting to not like all this testing, checking each and every lens etc etc to be able to have a reliable equipment.
If I could pay 100 € extra for each lens and therefore get a reliable tested lens and same for the body I would happyly pay that money.
HI Tom
I do sympathise.
I have 5 lenses which all seem to work properly - but truth to tell, like Lee, the 18-135 is pretty much welded on to the camera, and that seems to perform fine (I've long since stopped testing).

all the best
 

ptomsu

Workshop Member
I have to say after giving my new K5 a testrun I am still not totally convinced about the AF. Sometimes it seems to work fine and sometimes slightly off even in good daylight (I havent figured out if it depends on the distance).
Many images I get lack the latest sharpness even with good lenses.
I really like the color and filmlike look though.
Frankly I really starting to not like all this testing, checking each and every lens etc etc to be able to have a reliable equipment.
If I could pay 100 € extra for each lens and therefore get a reliable tested lens and same for the body I would happyly pay that money.
I fully support this! I am tired of testing once I have decided for a certain camera and would expect that all the lenses and accessories I buy (at least from the same brand) are ok - and willing to pay some extra for that!

Unfortunately with Leica you are paying that extra I guess - but ALL of my M lenses (also the new acquired ones) needed to go back for fine adjustment when I bought my M8. So high price is not a real guarantee unfortunately.

PS: I am so happy that I am not the only one who had AF difficulties with the K5 and lenses - THANKS! I thought already I would be sick :eek:
 

Sapphie

Member
I have to say after giving my new K5 a testrun I am still not totally convinced about the AF. Sometimes it seems to work fine and sometimes slightly off even in good daylight (I havent figured out if it depends on the distance).
Many images I get lack the latest sharpness even with good lenses.
I really like the color and filmlike look though.
Frankly I really starting to not like all this testing, checking each and every lens etc etc to be able to have a reliable equipment.
If I could pay 100 € extra for each lens and therefore get a reliable tested lens and same for the body I would happyly pay that money.
I am not sure if it may be an SR-related thing but I can't test this out until the weekend. For sure SR is *essential* in low light but I do wonder about it for shutter speeds > 1/100th second but then this may all be in my mind.

As far as I am concerned I like the output, colour, tone, DR so much that it is worth persevering. Hell, looking back over shots from other cameras they don't always look that sharp (and I am talking about as seen at 100% on-screen in LR). If anything, my Sony R1 was one of the sharpest and that had no SR ... (but a cracking Zeiss lens).

Can I ask 'how are we all judging sharpness or focus accuracy? 100% on-screen view or prints? I know from my film days that initial scans were deliberately on the soft side to aid appropriate sharpening for appropriate output.

Lee
 
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Paratom

Well-known member
I am not sure if it may be an SR-related thing but I can't test this out until the weekend. For sure SR is *essential* in low light but I do wonder about it for shutter speeds > 1/100th second but then this may all be in my mind.

As far as I am concerned I like the output, colour, tone, DR so much that it is worth persevering. Hell, looking back over shots from other cameras they don't always look that sharp (and I am talking about as seen at 100% on-screen in LR). If anything, my Sony R1 was one of the sharpest and that had no SR ... (but a cracking Zeiss lens).

Can I ask 'how are we all judging sharpness or focus accuracy? 100% on-screen view or prints? I know from my film days that initial scans were deliberately on the soft side to aid appropriate sharpening for appropriate output.

Lee
Lee,
I wondered about the SR too, but havent tried without yet.
I also wondered if the smaller size and weight of the K5 an lenses compared to a D700 (thats my reference of focus accurancy) might be more prone to shake.
Some images which are only slightly soft its hard to seperate if it is inaccurate focus, shake, noise reduction/ noise, soft lens or something else.
 
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