Is this a good deal

I was looking at this and just wondering if it's a good deal,

link

Hi Jason,

I have one of these - the quailty is good but auto-focusing doesn't work with SDM lenses.

The camera seems to know that the lens is SDM so it does not engage the worm drive. It will work OK if you don't have SDM lenses though.

SRS price for this is £129 so £99 is a good price. (SRS have the Kenco 1.4x adaptor for £89 which DOES work with SDM and is a good deal too)

Hi Jason i got something similar last week in a job lot with a pentax programmA / 3 lenses reversing ring / tmount and various other bits and bobs for £20.

So probably isn't a good deal at the price but i was very lucky.

Yours isnt autofocus

My bad

so if I have this right it will work on af with all standard lenses?

It will work on AF with all standard AF lenses.(I presume)
I really wouldn't recommend a 2x teleconveter though, 1.4x/1.5x or the Pentax 1.7x will give much better IQ

Ok I will keep looking for one of the others.

Not sure what you would describe as a 'standard' lens.

If standard means FA then yes as they are worm drive only.

If standard means DA then no as one (at least) of the DA lenses has SDM and the adaptor will not auto focus with lenses that have SDM.

Autofocus will work on lenses which ONLY have worm drive focusing.