[ScooterMaxi Jim]

Except when shooting very dark scenes, when the LV display degrades and the focus peaking halo loses visibility.

Then it's best to just focus normally with the optical viewfinder, but target whatever contrasty edge you can find in the scene, watch the green hexagon, and focus bracket a bit, as hcc has done.


Curl - Ben Jenkins on Flickr
K-5 , ƒ/2.0, 85.0 mm, 1/160, ISO 6400

Valid observation. I do a fair amount of club shooting similar to what you have posted here. It's close to a toss-up between the K-01 with a good screen loupe vs. the K-3 with OVF (using the LV without a screen loupe would be hugely distracting and difficult in the crowd). Still, with magnification utilized, I'd give a slight edge to the K-01 with screen loupe for focus accuracy; however, detail from the K-3 is superior with the 85mm - even at ISO 3200 which is my preferred limit on either camera.

[Na Horuk]

Oh yeah, one more thing, it is possible that it matters whether you are coming from infinity to closer, or from closer towards infinity. I think some tests showed that one way worked better with CiF than the other way.

You can just google that lens and "focusing problems" and find some more answers

[Another dyemention]

Well at the end of the day, I'm pretty sure there will be no real benefit to taking the kind of photos I'm planning on at 1.4 as opposed to 2.0 or even 2.8. Not saying I won't have a use for 1.4 but it won't be to take pictures of people dancing or moving around. I think it'll be pretty near impossible to get any good repeatable results. Pretty much be a luck thing. But 85 at 2.8 will still give me plenty good results. I will definitely try all these things in a much more controlled environment.

[ScooterMaxi Jim]

I've never had consistent success with CIF - even at middle apertures and little or no movement; focus comes out nearly correct, but almost never totally sharp. I must not know the proper technique. With lots of movement and shallow DoF, I don't think you can expect success with CIF. I know some folks use it for birds in flight - and that would be somewhat easier due to the contrast and distance compared to most other situations.

[UncleVanya]

I've never had consistent success with CIF - even at middle apertures and little or no movement; focus comes out nearly correct, but almost never totally sharp. I must not know the proper technique. With lots of movement and shallow DoF, I don't think you can expect success with CIF. I know some folks use it for birds in flight - and that would be somewhat easier due to the contrast and distance compared to most other situations.

With CIF you rely on PDAF and have to validate focus is not front or back focused just like you do with an AF lens. Did you calibrate the lens? I did not.

[ScooterMaxi Jim]

First of all, I tend to shoot MF even with AF lenses if the aperture is fairly wide open on my various primes. The lenses all behave similarly - failing to achieve exact focus based on confirmation timing to trigger, and the focus confirmation very clearly operates differently in CIF compared to regular PDAF. Yes, it should be the same, but it is clear that CIF is slower to react. My best results with CIF come when I select a particular focus point at which a subject is known to enter (and this still isn't perfect, typically a bit late; but much improved with the K-3 compared to earlier implementations). MF is a sharper route to go because the intent of the photographer is not the same as what the camera interprets - given the relatively sloppy focus points.

I admit, I'm pretty demanding about what constitutes proper focus. For instance, many find shooting portraits with an 85mm at around f/2.4 acceptable; I can't stand the lack of good focus across most of the subject's face. IMHO, f/4 is the widest acceptable aperture. Certainly, CIF is adequate for those who want only a moderately sharp image.

[Another dyemention]

So I'm back from the music festival and have to say I thought it would have been a bit easier to focus with this lens. I was probably about 50% for the weekend. Maybe less. I ended up using live view with the zoom and probably got about 60-70% focused shots. So not too bad. F1.4 was definitely as hard as I figured it would be. I mainly used 2.4-4.0. I think I will keep this lens as I love the rendering for portraits. The pictures are sharp but have a bit if softness to them that I love.
Festival season is over here in northeast ohio so I think I will ask Santa for the 50-135 for next season.
So thanks everyone for the tips and help. I think I'll keep this lens for tripod work and situations where I have time to get the focus right.

[redcat]

My experience with thin DOF manual lens is : I focus (either on VF or focus peaking), shoot, move the focus ring a bit on either side, shoot again. Out of 5 images, I usually get one in focus ^^

[stillshot2]

But I thought that the Samyang/Rokinison was not either. I thought it was A style.

You are right, I forgot that it is an "A" type lens.

[drypenn]

I've never had much lack with CIF too. If anything, it makes me feel lazy and complacent, and regretting it afterwards. With my failing eyesight, it's surprising that I have better keeper rates with manual focusing, stock screen using single shots.

I can't seem to figure out the CIF too. I don't know whether all of my 3 Pentaxes are faulty (unlikely), or if I'm just too dumb to learn how to use it.

[ScooterMaxi Jim]

I've never had much lack with CIF too. If anything, it makes me feel lazy and complacent, and regretting it afterwards. With my failing eyesight, it's surprising that I have better keeper rates with manual focusing, stock screen using single shots.

I can't seem to figure out the CIF too. I don't know whether all of my 3 Pentaxes are faulty (unlikely), or if I'm just too dumb to learn how to use it.

I'd say you are just like me. If a shot isn't pin sharp at the point of intended focus, then IMHO the shot is out of focus and not acceptable. Shooting faster than f/2 is a big challenge - especially anywhere past 50mm; so pick your poison and be sure to take enough shots to get one you find acceptable.

[Sagitta]

Another reason Live View may fool you is that in recent tests I have done and heard about it is clear that LiveView stops down the lens a bit. My tests indicate f/4 is where it stops down which would give much more depth of field than you actually have and fool the focus sensors a bit. My experimentation with the Pentax A* 85 f/1.4 before I sold it showed me that either LiveView nor focus confirmation worked 100% of the time. I found that using burst mode and moving the focus slightly during shooting at adequate shutter speeds gave me insurance (like bracketing the exposure). Many people told me that a better focus screen would help - I never tried that.

I'm a bit late to the thread (and pardon me if this has been answered already) but you can focus and use the DoF preview fuction (not sure its actual name - its the power switch, one notch past 'On') in Live View. Hold it down while focusing and you'll find MF wide open a lot easier.

[Another dyemention]

I'm a bit late to the thread (and pardon me if this has been answered already) but you can focus and use the DoF preview fuction (not sure its actual name - its the power switch, one notch past 'On') in Live View. Hold it down while focusing and you'll find MF wide open a lot easier.

I tried messing with that just to see what it does but I couldn't see it doing anything. It could've been the lens I was using but I will check it out this weekend. Maybe it will work better with a fast lens like the 85/1.4. If I recall, I tried it with my da 35 or my 18-135. So I'll check it out. Thanks

[ScooterMaxi Jim]

Be sure to set the menu function to optical preview. This isn't all that easy to find. It is in the 4th (last) of camera menus under Button Customization on the K-3. I prefer it on the collar, but you can have it on the RAW/Fx button along the side, if you prefer.

The optical stop down works both on the OVF and LV. It is especially helpful on the Samyang (et.al.) 85mm due to focus shift. The focus shift is most apparent from about f/2.2 to f/3.5 which is the aperture range I use most - especially in club settings.