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DA 300 AND F1.7 AF ADAPTOR

geordie01
Posted 29/05/2014 - 17:03 Link
Having got the 1.7 adaptor and liking the results on some mf lenses especially the A 70-210. When using it on the DA 300* do you folks set the lens to MF and let the adaptor do the last bit of focusing or just let the two of them whirr away happily together with the lens set to AF
Any thoughts
thanks
G
SteveEveritt
Posted 29/05/2014 - 18:25 - Helpful Comment Link
When attached to my 5iis the lens doesn't focus at all so I had to get it close and let the TC take. Very good results with the DA*300
Flickr
"Life is what happens to you while you're busy making other plans" (John Lennon)
weinelm
Posted 29/05/2014 - 18:36 - Helpful Comment Link
The DA* 300 doesn't autofocus when used with the 1.7x AF adaptor. The adaptor does all the focusing (the adaptor doesn't have the SDM contacts, so the lens essentially becomes manual focus). Because the focus range of the AF adapter is limited you have to focus the lens to approximately where you want it and then let the AF adaptor fine tune it. It sounds a bit cumbersome, but it actual works quite well, as you basically have a focus limiter. I get pretty good results with the 1.7x adaptor and the DA* 300. It's not quite so good (at least for me) with the 60-250mm.
Panasonic GX80, Pentax MX, Mamiya 6. My Flickr
weinelm
Posted 29/05/2014 - 18:37 Link
Steve you beat me to it!
Panasonic GX80, Pentax MX, Mamiya 6. My Flickr
Mike-P
Posted 29/05/2014 - 19:41 Link
weinelm wrote:
I get pretty good results with the 1.7x adaptor and the DA* 300. It's not quite so good (at least for me) with the 60-250mm.

Likewise.

The new Pentax 1.4x is better on the 60-250mm.
weinelm
Posted 29/05/2014 - 19:44 Link
Thanks Mike, that's good to know. I've been weighing up whether to go for the 1.4x TC or a K3 to get some extra reach on the 60-250mm.
Panasonic GX80, Pentax MX, Mamiya 6. My Flickr
geordie01
Posted 30/05/2014 - 11:14 Link
I thought that in the absence of sdm contacts the lens would work on the screw drive as it does on my K110d.
Never mind onward and upwards
bforbes
Posted 30/05/2014 - 11:20 Link
I think it's to do with the camera. The K110d could not be updated for SDM.
Mannesty
Posted 30/05/2014 - 15:18 Link
geordie01 wrote:
I thought that in the absence of sdm contacts the lens would work on the screw drive as it does on my K110d.
Never mind onward and upwards

I think you must be mistaken. The 1.7x AF adapter can't possibly focus the lens fitted to the front of it on any camera because there is no screw drive on the female side of the adapter, only on the male side.

Keep in mind that it was originally designed for use with MF lenses in the first place, the adapter providing the AF.
Peter E Smith - flickr Photostream
Edited by Mannesty: 30/05/2014 - 15:20
Smeggypants
Posted 31/05/2014 - 05:43 Link
Mannesty wrote:
geordie01 wrote:
I thought that in the absence of sdm contacts the lens would work on the screw drive as it does on my K110d.
Never mind onward and upwards

I think you must be mistaken. The 1.7x AF adapter can't possibly focus the lens fitted to the front of it on any camera because there is no screw drive on the female side of the adapter, only on the male side.

Keep in mind that it was originally designed for use with MF lenses in the first place, the adapter providing the AF.

it would be absurd to have a mechanical screwdrive focussing both the teleconvertor AND the lens anyway. Either one of the other but not both
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283
geordie01
Posted 31/05/2014 - 10:59 Link
Mannesty wrote:
geordie01 wrote:
I thought that in the absence of sdm contacts the lens would work on the screw drive as it does on my K110d.
Never mind onward and upwards

I think you must be mistaken. The 1.7x AF adapter can't possibly focus the lens fitted to the front of it on any camera because there is no screw drive on the female side of the adapter, only on the male side.

Keep in mind that it was originally designed for use with MF lenses in the first place, the adapter providing the AF.

Nope not mistaken
Lens works on 110d on screw drive, never tried it with af adaptor on that camera.
Gave it a go on K30 yesterday and it is very good
Mannesty
Posted 31/05/2014 - 12:17 Link
OK, I had assumed that since your original post was about the 1.7x AF adapter, as were all the other posts leading up to your second post that I commented on, I thought that you were referring to it's use on a K110D.
Peter E Smith - flickr Photostream

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