100mm DFA Macro New Purchase

Hello everyone

Im new here and pretty new to photography. Ive had a K100 for a few years with the kit lens and a tamron 70-300 but only really just started really getting into it.

Ive recently been purchasing a couple of lenses and have just bought a pentax 100mm dfa macro.

Im not sure if this is normal but the focus ring rotates still when at the extremes of the focus range. The focus does not change but the ring still rotates. Also when you ingage the focus lock you can still rotate the focus ring (albeit harder than when its not on but its not exatly locked)

Is this normal for these lenses? I have a 55-300 and a 16-45 and the focus ring on these is not moveable when at the extremes of the range.

The auto focus works fine as well as the quick shift and the focus lock stops the auto focus from working as expected.

When the image is taken there is a slightly higher pitched noise than with the other lenses i have too.

I bought it off ebay for £300 and it is supposed to be brand new.

Do i need to send it back?

Thanks
Rich

Hello Rich,

No need to worry, that is quite normal for the DFA 100 f/2.8 macro.

Yep, mine does the same - it's quite normal (plus I've sold a Samsung-badged version on eBay and that did the same too). Someone did explain once that it was something to do with the clamp but I can't remember exactly what they said.

In a nutshell: Don't panic, just enjoy it. It's a very fine lens.

That's because of the way the lens is make, there is a clutch between the focus ring and the actual focus elements inside the lens.
The reason is that the focus ring takes up a lot of space on the lens and when you hold the lens you will hold it on the focus ring as well most likely, it would be highly unpleasant if the focus ring will turn when using AF that's why there is a clutch between it.

The DA*50-135 also does the same and I'm sure there are also other lenses with the same feature.

Excellent.

Thanks for all the quick responses.

Im off to take some more pictures with my new lens now (-:

Wheres all those bugs!

Cheers
Rich

Be careful with this lens Richard. The images it produces are so sharp you can cut yourself.

Hi Gareth

No not the same one

Rich