TC for Pentax - really no AF?
Posted 05/11/2012 - 16:26 - Helpful Comment
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Your salesman is correct when he says "TC-S for Pentax are working ONLY with manual focus" but he should have also told you that the SMCP-F 1.7x AF Adapter will give you AF capability, even with a manual focus lens. It does have limitations, in that you need to roughly focus in manual first, it does not give you full range AF.
When fitted between the camera and lens, the AF capability of the lens is disabled and the TC does the focussing via the screw drive mechanism.
This TC works superbly with the DA* 300mm lens and with practice shows very little loss of image quality.
I believe this is the only AF capable TC from Pentax but other makes do exist.
When fitted between the camera and lens, the AF capability of the lens is disabled and the TC does the focussing via the screw drive mechanism.
This TC works superbly with the DA* 300mm lens and with practice shows very little loss of image quality.
I believe this is the only AF capable TC from Pentax but other makes do exist.
Peter E Smith - flickr Photostream
Posted 05/11/2012 - 17:15
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Thank you for useful comment! The lens is thatone: http://www.anpeq.org/product.php?id_product=1743
it should be with SDM, so not manual, as i understand. The same story as with manual lens? I think i should find some possibility to try this stuff, otherwise it΄s complicated to understand the working mechanism...
it should be with SDM, so not manual, as i understand. The same story as with manual lens? I think i should find some possibility to try this stuff, otherwise it΄s complicated to understand the working mechanism...
Posted 05/11/2012 - 18:15 - Helpful Comment
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The SMC Pentax DA* 300mm lens (the same as in your link) has both SDM and the older screw driven focus mechanisms.
If you were to use a SMC Pentax-F 1.7x AF adapter, neither of the lens's focussing mechanisms are used, instead, you roughly focus manually, then half press the shutter button and the AF adapter does the focussing. This is also how it can make a manual focus (MF) lens into auto focus (AF).
To summarise, the SMC Pentax-F 1.7x AF adapter works with both AF and MF lenses,but the AF mechanism of AF lenses is not used.
Hope that helps you understand how it works.
EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
If you were to use a SMC Pentax-F 1.7x AF adapter, neither of the lens's focussing mechanisms are used, instead, you roughly focus manually, then half press the shutter button and the AF adapter does the focussing. This is also how it can make a manual focus (MF) lens into auto focus (AF).
To summarise, the SMC Pentax-F 1.7x AF adapter works with both AF and MF lenses,but the AF mechanism of AF lenses is not used.
Hope that helps you understand how it works.
EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
Peter E Smith - flickr Photostream
Posted 05/11/2012 - 18:53 - Helpful Comment
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One other thing to consider is the light loss when using a teleconverter. The DA* 300mm lens has a maximum aperture of f4, this will be reduced to around f5.6 or f6.3 (I'm not sure of the maths to work it out). This may not be fast enough for you depending on the lighting environment when you intend to use it.
Peter E Smith - flickr Photostream
Posted 05/11/2012 - 22:00
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Impressive prices in the site you linked (anpeq)!
Posted 05/11/2012 - 22:37
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Mannesty wrote:
One other thing to consider is the light loss when using a teleconverter. The DA* 300mm lens has a maximum aperture of f4, this will be reduced to around f5.6 or f6.3 (I'm not sure of the maths to work it out). This may not be fast enough for you depending on the lighting environment when you intend to use it.
Yes f6.3 on 300mm f/4
One other thing to consider is the light loss when using a teleconverter. The DA* 300mm lens has a maximum aperture of f4, this will be reduced to around f5.6 or f6.3 (I'm not sure of the maths to work it out). This may not be fast enough for you depending on the lighting environment when you intend to use it.
PPG Wedding photography Flickr
Concert photography
Currently on a Pentax hiatus until an FF Pentax is released
Concert photography
Currently on a Pentax hiatus until an FF Pentax is released
Posted 06/11/2012 - 08:31
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To Mannesty:
EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
How did you understand then TC? Is it working then with autofocus? (Sorry for making a mess)
EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
How did you understand then TC? Is it working then with autofocus? (Sorry for making a mess)
Posted 07/11/2012 - 13:02
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Mannesty wrote:
EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
Except without the gramatically incorrect apostrophe.
EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
My Flickr Pentax K-5 K-5 II Sigma 8-16mm F/4.5-5.6 DC HSM Tamron SP AF 17-50mm F/2.8 XR Di II LD ASL SMC Pentax-DA* 50-135mm F/2.8 ED [IF] SDM SMC Pentax-DA 55-300mm F/4-5.8 ED SMC Pentax-DA 18-135mm F/3.5-5.6 ED AL [IF] WR Vivitar 100mm F/3.5 Macro AF Metz Mecablitz 58 AF-2
Posted 07/11/2012 - 15:49
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MarkTaylor wrote:
Wow, what an incredibly helpful post.
Mannesty wrote:
EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
Except without the gramatically incorrect apostrophe.EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
Peter E Smith - flickr Photostream
Posted 07/11/2012 - 16:18
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Mannesty wrote:
But it's more helpful to point out something was incorrect when your correction was still incorrect?
MarkTaylor wrote:
Wow, what an incredibly helpful post. Mannesty wrote:
EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
Except without the gramatically incorrect apostrophe.EDIT: Correction to my previous post:- Having re-read your original post I can see that TC-S is meant to be short for teleconverters, in which case your salesman was incorrect. In english it would be written tc's or TC'S.
My Flickr Pentax K-5 K-5 II Sigma 8-16mm F/4.5-5.6 DC HSM Tamron SP AF 17-50mm F/2.8 XR Di II LD ASL SMC Pentax-DA* 50-135mm F/2.8 ED [IF] SDM SMC Pentax-DA 55-300mm F/4-5.8 ED SMC Pentax-DA 18-135mm F/3.5-5.6 ED AL [IF] WR Vivitar 100mm F/3.5 Macro AF Metz Mecablitz 58 AF-2
Posted 07/11/2012 - 16:26
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What might be slightly more helpful to point out is that Pentax have a planned 1.4x AF teleconverter on their K-mount lens roadmap for (possibly) sometime in 2013... or later. Okay it's a bit vague but I think that's as much as anybody outside of Pentax knows right now.
My Flickr Pentax K-5 K-5 II Sigma 8-16mm F/4.5-5.6 DC HSM Tamron SP AF 17-50mm F/2.8 XR Di II LD ASL SMC Pentax-DA* 50-135mm F/2.8 ED [IF] SDM SMC Pentax-DA 55-300mm F/4-5.8 ED SMC Pentax-DA 18-135mm F/3.5-5.6 ED AL [IF] WR Vivitar 100mm F/3.5 Macro AF Metz Mecablitz 58 AF-2
Posted 10/11/2012 - 19:39
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The Kenko Pz-AF 1.5X TELEPLUS SHQ works with SDM lenses - tried it with my 18-135WR and the AF works fine!
OTOH, even these are expensive nowadays - £150+ - makes me glad I bought mine about 4-5yrs ago from SRS at half that price
OTOH, even these are expensive nowadays - £150+ - makes me glad I bought mine about 4-5yrs ago from SRS at half that price
K-3 II, K-3 and a K-70 from SRS (having now relegated the K-30 /"K-50" to a backup body), & some Sigma and Pentax lenses (and a lot of old 35mm gear!)
Posted 10/11/2012 - 21:17
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MarkTaylor wrote:
What might be slightly more helpful to point out is that Pentax have a planned 1.4x AF teleconverter on their K-mount lens roadmap for (possibly) sometime in 2013... or later. Okay it's a bit vague but I think that's as much as anybody outside of Pentax knows right now.
Judging the price of the recently launched Q to K mount adaptor I don't think the da 1.4 x tc will be very cheap either....
What might be slightly more helpful to point out is that Pentax have a planned 1.4x AF teleconverter on their K-mount lens roadmap for (possibly) sometime in 2013... or later. Okay it's a bit vague but I think that's as much as anybody outside of Pentax knows right now.
PPG Wedding photography Flickr
Concert photography
Currently on a Pentax hiatus until an FF Pentax is released
Concert photography
Currently on a Pentax hiatus until an FF Pentax is released
Posted 10/11/2012 - 21:52
Link
MarkTaylor wrote:
What might be slightly more helpful to point out is that Pentax have a planned 1.4x AF teleconverter on their K-mount lens roadmap for (possibly) sometime in 2013... or later. Okay it's a bit vague but I think that's as much as anybody outside of Pentax knows right now.
How hard can it be to make a ruddy SDM compatible teleconverter, Kenko did it years ago.
What might be slightly more helpful to point out is that Pentax have a planned 1.4x AF teleconverter on their K-mount lens roadmap for (possibly) sometime in 2013... or later. Okay it's a bit vague but I think that's as much as anybody outside of Pentax knows right now.
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3 posts
13 years
Estonia,
Baltic sea
K20D (having already) + DA 300mm f4 are in my mind, but when i asked from local (Estonian) seller, do the have teleconverter for Pentax, the salesman said, that TC-S for Pentax are working ONLY with manual focus. It seems unbelievable. And no help of such thing in shooting birds. Could you say something about it? Is it really so hopeless?