Manual Focus lenses vs Auto Focus lenses

I have a Pentax K20D and Kx cameras. Both work really well. I also have several Auto Focus Lenses that I use and I get reasonable good photos from these. BUT, I have several Manual lenses, both Pentax which I can not get sharp photos from. This is a mystery. I know the lenses are okay, I believe. I have tried every kind of setting on both cameras also, thinking it is the camera's fault, including the eye piece setting. I have a 200mm Pentax Manual lens with an F2.8 stop. I really like this lenses but against, photos are not sharp. I though possibly that it is my eye sight, but I am 20/20. I thought about getting a split screen for one of the cameras, but I'm not too sure of that. When I focus the Pentax 1.7 50mm lens, it looks sharp but after taking the picture, it's not. The Same for the 200mm Pentax lens. Anyone have any ideas??????

Check the adjustment of the eyesight correction slider on the viewfinder. Looking at a plain background (well lit interior wall, sky), adjust slider until the in-viewfinder markings are at their boldest. You should try to relax your eyes to focus on the far distance while doing this.

EDIT: Oops. On re-reading I see you have mentioned the eyepiece.

It's worth re-iterating the method to adjust the dioptre though as many users don't realise the viewfinder image should be out of focus whilst doing it so we can see when the etched lines on the focusing screen are sharpest.

Once the dioptre is correct then the focusing should be correct.

Are your AF lenses sharp when used with manual focusing?

Are your AF lenses sharp when used with manual focusing? That's a very good question....I don't know and I haven't tried to used them in manual focusing... I will try this out and get back to you.. tks

Thanks for this, just tweaked mine which hopefully will help as I have been finding manual focus not very sharp. Also there is a difference in setting when wearing glasses which I sometimes take off.

Well, I tested the AF lenses in manual mode and they were as sharp as in AF mode. I did readjust the dioptre but still I tried the 200 F2.8 lens and I 'think' it may be a little better but I'm not sure.

Thanks guys for your help and comments. Certainly appreciated.

Phil

I would set your camera up on a tripod (if you have one), or on a stable, level surface. Then focus your lenses in Live View mode on the rear screen, zooming in to make sure the focus is 100% correct. Then take a picture with the self timer and check the result. If it is not sharp, I would suggest there's a problem with the lens, if it is sharp then the issue lies with your focussing technique using the viewfinder. This may be due to the dioptre settings as has already been mentioned.

Hope this helps.

Regards
David

It is certainly possible to get sharp images with old MF lenses. I do it all the time. In fact, I probably use old MF glass much more than my new AF stuff.

Are you relying on your eyes, or the green hexagon? It seems fine on my K-3 but I did have problems with the K20D where the green hexagon was telling porkies.

K.

Kris is right there. You cannot rely on the green hexagon. In fact it sometimes lights, with a bleep in different places depending whether you are focussing inwards or outwards. The best test is with live view, as described above. You'll be amazed what a difference the tiniest tweak will make. I also find that preset lenses are easier to use (preset to f22, for example) because you can focus wide open and then simply twirl the aperture ring and watch the (stepless) d.o.f. changing before your eyes.

David

'I would set your camera up on a tripod (if you have one), or on a stable, level surface. Then focus your lenses in Live View mode on the rear screen, zooming in to make sure the focus is 100% correct.' I will try this and let you know what happens

Phil

Well................

David, you were correct! I put the lens on a tripod and focused it in Live View and sure enough I got a good photo. So the problem was me. I'm both surprised and disappointed. As the lens is an F2.8, I thought it was fast enough to cope with this sort of thing. That means, that I have to be very careful when taking hand held shots with this lens and focusing it; I need to make sure that I'm focused correctly and the camera is very stable. I put a doubler on it and got the same results. I haven't tested my Pentax-a F1.7 lens yet.