Originally posted by tomO2013 Ok further update....
I think I've narrowed this weird low light behaviour down to PDAF focus settings in AFS. I'm convinced a firmware update will quietly update this. And I have confirmed behaviour on two shop bodies.
If you enable AF-S but have focus priority (even with center point) enabled the camera will focus to the point, hesitate frustratingly, then light up the focus point LED and release the shutter. This hesitation is crazy because of the aforementioned post with CDAF being faster in live view than OVF and PDAF.
Switching the PDAF and AFS to release priority and it's an entirely different ball game and makes a huge difference to focus performance and camera operation for event work. A half depress has the camera racing to focus and a full press has it light the focus LED and grab the shot. Even test shots going from infinity to close with a full depress of the shutter in this mode have yielded in focus and accurate shots. It's blazing quick with 24-70, 15-30, the 3 amigos and even 70-200.
Tonight I've done a side by side with a buddy with a D750 (set to release priority as well as well as focus priority) in single shot AFS.
In the ISO6400 and low light (possibly -2EV) the K1 was both noticeably faster and more accurate when both had their focus point set to center af point. Pentax with the DFA* 70-200 and Nikkor 70-200 F2.8 on the D750. Both wide open at F2.8.
For now I've my camera set to release priority and I'm suddenly really enjoy this camera a lot - it's focusing is pro-grade DSLR quick
Hi everyone !
I can't tell you how useful are these informations. Thank you so much @
tomO2013, and all of you for this precious knowledge.
First it's important to say that I'm a
very inexperienced photographer (I prefer to call myself a "picture taker") who had the opportunity to shoot (very) intensively. I did architecture during 2 months using a Fuji XM1, tried a Nikon D3100 for one month (portraits) and bought a K1 45 days ago in order to use my dad's old SMC Pentax M optics (SMC-K 50mm F1.4, SMC-K 35mm F3.5, SMC-K 75-150mm F4, SMC-K 35-70mm F2.8-3.5, Hisawa 200mm F4). I choosed a DFA 24-70mm F2.8 and a FA 50mm F1.4.
I started to shoot improvisation and dance shows for a month now (about 7 representations lasting 2 to 4 hours each)
in low light environnement. I noticed that about 85% of my pictures were out of focus, at that point, I've already spent hours reading about focusing techniques, manual focus, focus traps, focus modes and focusing scenarios. I came to the conclusion that I had a bad focusing technique, and read more and more. I tried to fire faster, stop breathing, crouch, prone, use tripod and every focusing modes / selections possible on the K-1 even if I knew there weren't appropriate to the situation, always the same result: 85% percent of not-so-sharp pictures **BUT**, I' never tried to switch release / focus priority... As I can often verify it, gear won't replace a solid experience.
Yesterday I saw this post, set the shutter to release priority before the night show, equiped my big Īss 24-70, and.... SHARPNESS, sharpness everywhere. I took 500 photos as always during 2 hours telling myself that I'll be compelled with throwing 85% as usual but 85% of my pictures where focused, I could achieve quick focus locks with so little light, that I could finally stop worrying about focus and start composition work, so good, soo so good.
**Warning, what follows needs further testing and knowledge to be confirmed, these informations come from my experience which is way to small to be an assertion.** Then I used the FA 50mm and I struggled as usual (in low light only) to get an accurate focus. I checked every single photo I took with this lens yesterday and I only used cross type sensors to focus, in AFS SEL with one movable dot on static actors, **BUT** I never tried to use only the center sensor which I realise would have been a good check. In a few days, I'll have to shoot an event in a probably low and / or crappy light, I'll try to use different sensors while shooting fast and still on non moving actors, and see if I can point a systematic behaviour of the body coupled with the FA 50mm. It was a calibration problem
It may be important to add that I was
never allowed to use AF light assist during shows for obvious reasons.