D FA 70-200mm compatibility with 1.4x L teleconverter

retired2007 · 03-24-2019, 11:48 AM

please excusse my old brain for not comprehending this. please correct me, k-1 with a 55-300 da hd 4-5.8 ed wr lens will give me 450mm in the crop mode and if i ad the 1.4 tela converter i would get 630mm ?
second senerio. k1 dfa* 70-200 in crop mode =300mm and with the1.4 tela =420mm?

**monochrome** · 03-24-2019, 12:12 PM

Originally posted by UncleVanya

Like Sandy mentioned putting it on the Kp, K3, K3ii, K70, etc. will get 24mp into the crop zone of the lens which is more than the 16mp in the crop zone you get from the K1 in crop mode - allowing for higher detail when you need reach. It is likely that the DA 1.4x would work both in K1 crop mode and on the crop cameras without limitations but I don't have any direct evidence of this.

---------- Post added 03-22-19 at 11:07 AM ----------

While this is true of the AF TC's the 1.4x-S and 2x-S manual focus converters (A series or not) will not transmit the SR data and allow the body to be set to whatever SR value you want - if manual focus is sufficient.

My past experiments using the 1.4x-S vs. the DA 1.4x lead me to think the 1.4x-S A version is very close to the same performance at least with my FA* 300 f4.5 used on a K-3.

The 1.4x-S should also cover the FF sensor without problems.

Ditto. I have a KP and have also used it with A1.4x-S with FA*300/4.5. IMO the A1.4x-S is the best of the TC lot.

**RedBoomer** · 03-24-2019, 05:07 PM - **1 Like**

I often use the DA 1.4x with the DA* 300 on my K1ii. However, I was on vacation a couple of months ago and the SDM failed on my 300 so I put my DFA 70-200 in its place. I have attached the landscape photo at 70mm (98mm with TC) and the bird at 200mm (280mm with TC) so that you can see the vignetting and corner issues. Otherwise the combination works well. Both photos are uncropped and taken in FF mode, not crop mode.

normhead · 03-24-2019, 05:42 PM

Originally posted by UncleVanya

I would defer to Norm - he has a lot of experience with this. Norm what about the F 1.7x converter?

The 1.7x converter is awesome, the subject ones out of range and you have to refocus. It acts as a focus limiter for some of the fastest AF anywhere as long as the subject stayss within range. But if your subject is moving around a lot it's a pain in the derriere. Many days it really depends on how good the manual focusing action is on the lens you use it with. Awesome on my Tamron 300 2.8, not so good on my DA* lenses.

Last edited by normhead; 03-24-2019 at 05:55 PM.

03-24-2019, 11:48 AM	#16
retired2007 Veteran Member Join Date: Aug 2011 Location: new Albany IN Posts: 861 Original Poster	my foggyness please excusse my old brain for not comprehending this. please correct me, k-1 with a 55-300 da hd 4-5.8 ed wr lens will give me 450mm in the crop mode and if i ad the 1.4 tela converter i would get 630mm ? second senerio. k1 dfa* 70-200 in crop mode =300mm and with the1.4 tela =420mm?

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03-24-2019, 12:12 PM	#17
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	Originally posted by UncleVanya Like Sandy mentioned putting it on the Kp, K3, K3ii, K70, etc. will get 24mp into the crop zone of the lens which is more than the 16mp in the crop zone you get from the K1 in crop mode - allowing for higher detail when you need reach. It is likely that the DA 1.4x would work both in K1 crop mode and on the crop cameras without limitations but I don't have any direct evidence of this. ---------- Post added 03-22-19 at 11:07 AM ---------- While this is true of the AF TC's the 1.4x-S and 2x-S manual focus converters (A series or not) will not transmit the SR data and allow the body to be set to whatever SR value you want - if manual focus is sufficient. *My past experiments using the 1.4x-S vs. the DA 1.4x lead me to think the 1.4x-S A version is very close to the same performance at least with my FA 300 f4.5 used on a K-3.** The 1.4x-S should also cover the FF sensor without problems. Ditto. I have a KP and have also used it with A1.4x-S with FA*300/4.5. IMO the A1.4x-S is the best of the TC lot.

03-24-2019, 05:42 PM	#19
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by UncleVanya I would defer to Norm - he has a lot of experience with this. Norm what about the F 1.7x converter? The 1.7x converter is awesome, the subject ones out of range and you have to refocus. It acts as a focus limiter for some of the fastest AF anywhere as long as the subject stayss within range. But if your subject is moving around a lot it's a pain in the derriere. Many days it really depends on how good the manual focusing action is on the lens you use it with. Awesome on my Tamron 300 2.8, not so good on my DA* lenses. Last edited by normhead; 03-24-2019 at 05:55 PM.