Pentax AF adapter 1,7

!Karen · Joined: 20 Jul 2013 Posts: 837 Location: Belgium Baby

Does anyone have experience with this thing in combination with pentax lenses?
I found it in a thrift store attached to a smc pentax 135/2,5 lens.
Wondering if it is worth buying a AF pentax camera for

tb_a · Expire: 2019-08-28

Maybe this will help you further: http://www.pentaxforums.com/lensreviews/Pentax-Rear-Teleconverter-F-1.7x-Autofocus-Adapter.html

DConvert · Joined: 12 Jun 2010 Posts: 902 Location: Essex UK

I paid a fair bit for mine, and as is often the way the used price dropped by about a third within a month.
It's a good quality TC, and the added feature of fine tuning the focus can be a bonus.

Loosing a stop & a half of light can limit the lenses the AF works with. Unfortunately my telescope won't reach prime focus with a SLR or it would have been brilliant with that, giving me AF on a ~950mm. My other long lenses are a trifle slow for it.

This year I'll give it a go for close ups, pared with a 200mm or 300mm prime it should work well for butterflies Smile

marcusBMG · Joined: 07 Dec 2012 Posts: 1304 Location: Conwy N Wales

I know how to use one of those, I'll take it off your hands. How about a €100? Smile

!Karen · Joined: 20 Jul 2013 Posts: 837 Location: Belgium Baby

Ok, so I now have a pentax K10D and two of those adapters Rolling Eyes

I was excited to be able to get some results with MF lenses but I can’t get it to work.
They both work with autofocus lenses.
But when I attach a MF lens to them the F- - on the camera just blinkt and I can’t Release the schutter.

Any ideas? Probably some setting I need to change but I don’t know my way around Pentax camera’s at all :-/

Sjak · Joined: 29 Sep 2017 Posts: 696

Did you use manual lenses before on your Pentax? If not, there's a few steps to take before the camera will shoot: https://www.youtube.com/watch?v=gUE0aQBy2D4
(on my K100D, I have to use the AEL-button as it has no green button)

!Karen · Joined: 20 Jul 2013 Posts: 837 Location: Belgium Baby

!Karen · Joined: 20 Jul 2013 Posts: 837 Location: Belgium Baby

Did a very quick first test

OK, first of all
That screen at the back of the K10D is absulute garbage Laugh 1

But viewing the pictures on the computer afterwards gave me a good first impression Wink

The adapter focusses very accurately with the 50/1.4
Pictures have clearly green CA. Not sure if that is worsened by adapter or a consequence of shooting at 1,4 (I have never used this lens before)
Need to investigate further

If anyone wants me to test with another manual pentax lens, the only other ones I got are a SMC 135/2.5 and SMC 100/2.8

The equipment:

The pics:
I only fixed the exposure as I was shooting in manual mode and it was very hard to judge on the screen... All 3 wide open

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Sjak · Joined: 29 Sep 2017 Posts: 696