All Forum Comments
Comment by RRattner posted on Wi-Fi Transfer of Photos - K-S2 at 03/02/2025 - 20:06
Thank you.
Comment by RRattner posted on K-S2 ISO Settings at 03/06/2023 - 20:31
Comment by RRattner posted on Problem Focusing with Pentax SMC DA Series 50-135mm f/2.8 ED IF SDM at 31/07/2018 - 01:02
I have this lens, by and large it is very accurate at focusing on both my K-3 and K-5iis, but has required some fine AF adjustment on both. Also, in common with many other lenses (and camera bodies) it's a bit more hit and miss in low light, something I've noticed most when doing gig photography where light levels can be very poor. Consider when adjusting the fine AF you can never get it 100% right because this is a zoom lens and the focus inaccuracies may (will) differ at different focal lengths. My suggestion would be to adjust the AF at a middling focal length, or at the one you are likely to use most often. The technique I use is as follows:
- Place on a tripod and shoot a subject with good contrast at a medium distance, with the subject angled at approx 45 degrees to the lens. A white ruler, or a white page with black writing is a decent subject
- Set to F2.8 aperture and focus using AF and the viewfinder (not Live View), take 3 images and for each image make sure the lens is de-focused and then re-focused using AF prior to pressing the shutter
- Review all three images (easiest to do on a PC monitor) to see if you have a consistent front or back focusing problem. You may find some variation, if necessary repeat until you see a definite pattern emerging
- Once you've established whether you have a front or back focusing issue, adjust using the AF Fine adjustment in the camera menu, ensuring you only it apply the adjustment for this single lens
- Once adjusted, repeat the steps above and re-adjust if necessary until you hit a 'happy medium'
Once you've done this you will be at the closest point possible to reliable focusing, but please bear in mind that you may still experience some issues especially using the lens at its widest apertures. 135mm and F2.8 makes for a wafer-thin depth of field, so errors are not unusual.
Please don't give up on the DA*50-135, it is one superb lump of glass.
Cheers
David
Comment by RRattner posted on Problem Focusing with Pentax SMC DA Series 50-135mm f/2.8 ED IF SDM at 31/07/2018 - 00:54
Does the ks2 have af fine tune adjustments?
Any technical help out there? Thanks.
Comment by RRattner posted on Problem Focusing with Pentax SMC DA Series 50-135mm f/2.8 ED IF SDM at 30/07/2018 - 12:28
Thank you.
Comment by RRattner posted on Problem Focusing with Pentax SMC DA Series 50-135mm f/2.8 ED IF SDM at 22/07/2018 - 03:24

