Difficulty in focusing with manual focus lenses


Oppenheimer45

Link Posted 15/11/2009 - 00:23
Following very helpful advice from the forum I purchased a Pentax SMC A 50mm f1.7. I also bought a Sigma 90mm f2.8 macro. Having tried out both lenses at home I am noticing that the camera focusing aid green hexagon does not always show up and it is difficult to get the focus just right. My camera is a K100D Super with it's original software. Am I doing something wrong. When the focus is right the pictures are lovely and sharp.

Regards

Rob

ps was the Sigma lens a good lens to get ?

iceblinker

Link Posted 15/11/2009 - 01:03
The green hexagon doesn't show up when the contrast or light coming from the subject is very low. In that situation, try focusing on a different part of the subject, or just use your own judgement based on how sharp the image looks on the focusing screen.

A Katz Eye screen can be worth buying if you plan to use manual-focus lenses for a long time.

Using smaller apertures helps as well when you don't mind greater depth of field.
~Pete

Oppenheimer45

Link Posted 15/11/2009 - 09:50
Pete

Thanks for that, I hoped that this was what the problem was.

Regards

Rob

johnriley

Link Posted 15/11/2009 - 10:48
Make sure you have adjusted the eyepiece dioptre setting properly. Look through at a plain unfocused surface or sky and adjust until the etched lines are crispest.
Best regards, John

Oppenheimer45

Link Posted 15/11/2009 - 13:21
John

Thanks for that, yes I have done this already after reading your comments on one of the other topics.

Much obliged for all the help supplied.

Rob.

pschlute

Link Posted 15/11/2009 - 15:28
In my experience the green hexagon is not a great aid in manual focus. If you get yourself a split prism focus screen however, that will be.
Peter



My Flickr page

Oppenheimer45

Link Posted 15/11/2009 - 16:03
Peter

Will be investigating spilt screens/Katz Eyes.

Regards

Rob
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