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05-27-2011, 04:22 PM   #1
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Kx focusing adjustments?

Hello. I recently bought a Rikenon 50mm f1.7 which I only manage to get in focus about half the time. Under the reviews of this lens, one forum contributor wrote "found this Ricoh actually in focus accurately by default without having to adjust the In-camera focusing points! If you know the Kx well, the Kx actually having Built in focus adjustment in the camera . . ." (PS. I don't know how to lift a quote from one place and stick it in another. I guess that's obvious). Anyway, I have no idea what this person is talking about. Is there a way on the Kx to fine tune focus?

On a related note, is it possible for a person with not such great eyesight (typical middle age disability to clearly see things close up, for instance, reading) to get pictures in focus using a manual lens? Thanks for any insight you can give because I either need to make some in camera adjustments or stick to auto focus. Jim

05-27-2011, 04:39 PM   #2
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The focus adjustment is for AF only. For manual focus, you still have to rely on the focusing screen. The problem is, Pentax DSLRs' viewfinders aren't optimized for manual focus, and the focus assist within the viewfinder is not precise enough imho. You can either try some third party split image focus screen, or train yourself on manual focus. Also, you might look for an used 2X viewfinder magnifier which helps. I don't know how the LV works on the K-x, but it may help if it can zoom in.
05-27-2011, 04:55 PM   #3
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What do you meant by focus assist within the viewfinder? I did wind up buying one of those Pentax 1.3 magnifying eyepieces. Hope that helps. I also do find that LV helps for focusing, but I've finally made the switch from Point and shoot screen shooting to viewfinder shooting, and I now prefer the viewfinder.
05-27-2011, 05:06 PM   #4
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The focus assist is the green hexagon within the viewfinder. When the camera thinks it's in focus, it will light up.



The O-ME53 doesn't help much but works great as an extended eyecup. The FB 2X magnifier has been discontinued so you will have to find on used market. It might be getting rare though.



05-27-2011, 06:37 PM   #5
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I find the 1.3 magnifier does help - not hugely, but it's definitely noticeable over time.

The real problem is that the viewfinder shows *too much* in focus at f/1.7. This is easy to verify by shooting some text at an angle - note how many lines appear in focus in the viewfinder, then see how many turn out to actually be in focus. So some of what appears to be in focus will turn out not to be. That's what makes it hard to focus manually with fast lenses, but with practice, you can learn to anticipate this effect.
05-27-2011, 09:07 PM   #6
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Ok, yeah I know what the focus assist is, and all of my out of focus pictures were taken when the in-focus light came on.

Marc, If I shoot at higher f stops will I have more in-focus pictures. I do tend to shoot a lot at f1.7, so maybe that's part of the problem.

But going back to my original question, does anyone know what this ricoh reviewer was talking about when he mentions 'in camera focusing points' and 'built in focus adjustment' with the Kx?
05-27-2011, 11:23 PM   #7
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Presumably he is talking about the unofficial/unsupported hacks some people use to enable a special undocumented debug mode that allows you to fine tune the AF system. Do a search for "k-x debug mode" and you'll find info. But it's totally irrelevant for a MF lens. It's only relevant for AF, and then, only if your camera is not well adjusted. Many people do lousy focus tests and end up using this mode to "correct" problems that never existed, but were instead just phantoms of bad testing procedure.

But yes, when shooting at an aperture that produces more DOF than than viewfinder shows - this happens somewhere between f/2.8 and f/4 - you should have an easier time focusing.
05-28-2011, 02:27 AM   #8
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It is not really clear what the reviewer is actually meaning by his statement, but it could be a reference to the 'catch in focus' feature? I find that helps with manual focus lenses. If you set catch in focus and hold the shutter down, the shutter will fire when it detects something in focus and the focus hexagon will light up in the viewfinder. You also need to make sure you know exactly where the camera is finding focus, so on the Kx I have it set to centre spot permanently so the camera doesn't catch focus from something off to the side. Catch in focus can be a bit hit and miss and it will also be more accurate either sliding through focus from near to far or vice versa, you need to do a bit of playing to work out how it works with your particular lens and a smaller aperture does help with depth of field and sharpness. The following was catch in focus with a Pentax 50 1.4, I think it was set to about f4. This was much sharper than I normally get though


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