[dr5chrome]

Hello all - Curious if anyone has focus issues with their K1?

I use mostly manual focus lenses on the K1. The problem i am having is odd.

Through the viewer, the subject is in focus. The cameras focus alert goes off and says its in focus, yet the image it self is not in focus.
So how can this happen? sharp in the viewer, out of focus file ?

regards,, dw

[brainwave]

Hello all - Curious if anyone has focus issues with their K1?

I use mostly manual focus lenses on the K1. The problem i am having is odd.

Through the viewer, the subject is in focus. The cameras focus alert goes off and says its in focus, yet the image it self is not in focus.
So how can this happen? sharp in the viewer, out of focus file ?

regards,, dw

Sounds to me like diopter settings are not correct. If the focus alert and focussed picture are in agreement, and only your viewfinder is not, it sounds like the diopter might need retuning.

[kiwi_jono]

My K-1 focus seems to be pretty consistent between what I see and the final product, however its pretty hard to tell if its really in focus just with the OVF - without a focusing aid (such as split screen). Especially so for lenses faster than f2.8. The in focus indicator has a bit of leeway too so is not a guarantee that its focus.

Have you tried fine tuning AF with focus chart and correct technique. I find its well worth doing every time I get a new lens or after a year or so (where I check it again - although the K-1 AF adjustment seems pretty stable over time unlike my K-5)?

[jatrax]

Set up on a tripod to prevent any motion. Focus using the viewfinder, then switch to Liveview and see if the image is still in focus. If not, then your diopter needs adjusting. The camera's focus alert is indicative but not precise enough especially with fast lenses. It is a good guide and very useful but it can get fooled.

[stevebrot]

It is a good guide and very useful but it can get fooled.

Yep...it is pretty eye opening to consider how long the hexagon stays lit when continuing to rotate past the initial indicator of "focus attained".


Steve

[dr5chrome]

Thanks all - I have adjusted the diopter, and yes the lenses I am using are fast - f2, 1.8, 1.4, 1.2

The effect I am going for requires I use fast lenses. I don't have this issue with my 645 or 67, only the K1.
Even if I use my insanely sharp 67 105 2.4 I still have focus issues on the K1. [what id give for a split-screen].

I even went and put a magnifier on the K1, still there is problems.

Will the AF tuning help with manual lenses?

I dont get why it is sharp in viewer and soft in the file...

dw

[jatrax]

Will the AF tuning help with manual lenses?

AF tuning will adjust the focus indicator but with fast lenses like you are using I doubt that is going to help.

I dont get why it is sharp in viewer and soft in the file...

If sharp in the viewfinder but the resulting image is sharp then the diopter is off. Assuming all other aspects are correct such as shutter speed, camera movement and so on.

Test your diopter by focusing with it and then comparing to a Liveview focus when on a tripod

[dr5chrome]

Using a tripod.

I have had better result with the peak focus, but it isnt 100% Maybe the K1's viewer is not all that precise and is built for autofocus.
Going to try a magnifier.

thanks again.

[UncleVanya]

Hello all - Curious if anyone has focus issues with their K1?

I use mostly manual focus lenses on the K1. The problem i am having is odd.

Through the viewer, the subject is in focus. The cameras focus alert goes off and says its in focus, yet the image it self is not in focus.
So how can this happen? sharp in the viewer, out of focus file ?

regards,, dw

In reality the focusing screen is only as accurate as the shim used to place it at the correct distance so that images focused there are also in focus on the sensor. Typically if the screen hasn’t been changed it will be relatively accurate. However the screens are optimized for autofocus - they stay bright at smaller apertures than the split screen ones do. There are third party screens that you can get to give you the split screen if that’s the main need. This will negatively affect spot metering. The screen will require careful shimming to get the accurate focus that you are seeking.

Additionally, when you talk about focus indicator, do you mean the red dot showing the active focus point or the green hexagon a showing focus lock? The red lights up sooner than the green typically and confused me at first until I learned to look at the hexagon.

Having tried using multiple methods with my A* 85 f1.4 I came to the conclusion My eyesight wasn’t good enough to use it on modern digital cameras. I didn’t change my k-3 screen however. Magnified Liveview is the mode that works best for me with fast manual focus lenses. Note I don’t have a k-1 I own a KP and k-3.

[Markovo]

Another thing to consider - when shooting f1.4, f2.8 and etc, even the slightest movement after you hit the shooting button will move the camera back or forth, changing the distance from the object in focus. Happens every time with my 50mm f1.4 and D-FA 100m macro... Try shooting faces with 100mm macro at f2.8. You'll got 1 of 10 photos focused right....

[noelpolar]

I replaced my focus screen in one of my K1s with a canon S screen.... and I use a Tenpa 1,22x viewfinder thingy.... this made a world of difference for me for my K lenses.... 50/1.2, 85/1.8 etc. I find the tenpa much better than the pentax magnifier eye piece (I have both).

https://www.focusingscreen.com/product_info.php?cPath=25_152&products_id=142...ih43q79pg7dr64

Screen needed a shim change.... which they provided.

Viewfinder maybe looses a bit of brightness.... <1 stop......but no real issues... shooting my DFA 150-450 afterwards.

[Henrico]

In fact that's the case with all my (d)slr's like K2, ME-super, K1 & KP. Using bright lenses wide open or longer tele's with very narrow DOF the matt screen and sharpness indicators are not 100% reliable. It has to do with very small unequal distances to the screen and the sensor/film. Using live view and 8x magnification is way more accurate and often spot on.

[biz-engineer]

So how can this happen? sharp in the viewer, out of focus file ?

This can happen if your eye is out of focus, uncalibrated

[Bob 256]

To get the absolute best focus with the K-1, use Liveview and magnification (rear thumbwheel) with manual focus. You're seeing exactly what the sensor is seeing. This won't work too well for moving objects; only static scenes and usually with the K-1 on a tripod. However, as UncleVanya mentioned, it's a great way to establish a true focus point to which the optical viewfinder system can be compared. If the grid lines in the OVF appear sharp and clear to your eye, then it's not a diopter issue, and you have the diopter setting where it belongs. If the image is out of focus (having previously established a good focus with Liveview and magnification), then it's a focus screen/mirror issue and you might have to have the camera looked at. If that is the case, then bringing the image into sharp focus (manually) using the OVF is actually defocusing the image from an optimum focus and the autofocus could well have the same problem. (Note: the contrast focus which Liveview uses is not dependent on the mirror/pentaprism path so it should be correct even if the optical phase focus is in error.)

[UncleVanya]

To add to this. The level of precision in mount distance to sensor and focusing system has to be more precisely aligned than in the past. At the same time focusing screens have a reduced role to play so they are made to be bright and appear in focus over a wider range of focus than in the old manual focus days. The tolerance for out of focus at the screen is higher and thus the ability to fine focus by eye is reduced using the stock screen. The fine focus adjustment offsets this for the autofocus system allowing you to bias the autofocus (and focus confirmation) system to some degree to ensure that the image on the sensor is in focus. However the precision of the non-liveview af system is meant for around f2.8 lenses. The faster lenses tend to focus a little sloppily in this model and there’s an art to ensuring you catch the right position in the “in focus indicated” range of manual focus lenses.