[awaldram]

If they do make a 2x it will be most useful on the DA* 200 2.8, DFA 70-20 2.8, and usably the 100 macro for those who want a nice light small telephoto option. For years I had my A 600 5.6 snd DA* 200 2.8. The 2x would have given me 400 5.6 and would have let me leave the A-400 at home. That being said, on a bright sunny day the DA*300 ƒ4 an the 2x will probably provide some decent images if circumstances are right. I wouldn't recommend buying a 2x TC for an ƒ4 lens, but if you bought it for something else, I'd certainly give it a test run.

Well my Bigma would happily focus with the Sigma 2X matched converter so maybe applying 'Cannon' rules to Pentax AF system is flawed.

Safox will quite happily focus @F14 (ish) in good light
https://g3.img-dpreview.com/87CF9AA55F424FE885F69BD765AE4A8F.jpg
Canon not so much

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Last edited by awaldram; 11-07-2018 at 08:55 AM. Reason: add image

[normhead]

My problem with 2x on higher than ƒ4 is performance, not focus lock. It can be difficult to lock focus on moving targets, it takes longer sometimes resulting in missed shots.. 2.8 definitely works best, with degraded performance as your lens gets slower and slower.

[thibs]

Well my Bigma would happily focus with the Sigma 2X matched converter so maybe applying 'Cannon' rules to Pentax AF system is flawed.

Safox will quite happily focus @F14 (ish) in good light
https://g3.img-dpreview.com/87CF9AA55F424FE885F69BD765AE4A8F.jpg
Canon not so much

And I thought Pentax AF was inadequate.

[normhead]

And I thought Pentax AF was inadequate.

Pentax AF.c and tracking are inadequate. But you can be an AF.s shooter you can enjoy some of the best AF out there.

I just don't have a lot of cause to use tracking. So for me Pentax AF works just fine.
And when I do use tracking I get some results I wouldn't expect listening to folks on the forum complain about how bad it is. It may not be up to Canon, Nikon and Sony high end action camera standards, but it's not a complete waste of time either.

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Last edited by normhead; 11-09-2018 at 08:27 AM.

[str8talk83]

Pentax AF.c and tracking are inadequate. But you can be an AF.s shooter and enjoy some of the best AF out there.

I just don't have a lot of cause to use tracking. So for me Pentax AF works just fine.

I have used Canon, Nikon, Pentax and Sony and will back what Norm is saying. Single shot AF is great with Pentax, even in low light. I would avoid the 2x TC except for Macro or f/2.8 glass. There is a difference between “working” and producing quality images that I would actually keep. I prefer for poor images being the fault of a mistake I made and not a limitation of my gear.

[davesofnj]

I confess I was hoping for a 1.7x FF.

The first point I'd make is that the image quality has to be very high (such as is delivered by the existing 1.4x APS-C teleconverter). There's no point in using a teleconverter if Photoshop can do as good a job in post.

Secondly, I'm almost exclusively a bird photographer, and frankly most of the time I prefer using my K-1 MkII (upgraded) in APS-C mode because: birds tend to fit into the smaller frame and you can shoot at 7 frames a second rather than 3. So, a 1.4x FF teleconverter will only have marginal value over what I already have -- I estimate that fewer than 5% of my shots are full frame; it might be as low as 2%.

Thus, a 1.7x teleconverter (even an APS-C one) would give me more range than what I already have and my sense is that to achieve the quality I see as being necessary it will be significantly more expensive than the 1.4x with a potential 2.0x dramatically more expensive and mostly more than I need in most circumstances.

FWIW, I use my 1.4x mostly with the 150-450 mm zoom. But if I'm going out with family or I'm going to be doing a long walk (particularly through sand) I'll use it with the 55-300 mm lens (I have the Pentax HD PENTAX-DA 55-300mm f/4.5-6.3 ED PLM WR RE Lens). Occasionally, I'll use it with the 300 mm prime lens. I'm pretty happy with the focusing speed in all these combinations although as others have said, tracking is frustrating. I also have a sense that focusing is not quite as good with the upgraded K-1 MkII as it was before the upgrade when I'm using spot focusing -- but that might just be that as I get older (pushing 75 right now) my handheld prowess is more shaky than it used to be!

Dave

[MegaPower]

this is a long wait, finally

[reh321]

I have used Canon, Nikon, Pentax and Sony and will back what Norm is saying. Single shot AF is great with Pentax, even in low light. I would avoid the 2x TC except for Macro or f/2.8 glass. There is a difference between “working” and producing quality images that I would actually keep. I prefer for poor images being the fault of a mistake I made and not a limitation of my gear.

I was a Canon user for many years. Even my Rebel could focus using f/4-5.6 lenses and a Kenko 2X TC. Was this as good as a white lens could do? No - but I dwell in the land of "the possible", and a white lens simply wasn't going to fit into my budget, just as a Pentax-DA560mm isn't. Right now, my "long" solution is a Sigma 70-300 on my Q-7 .... no AF at all, but again it makes some photographs possible. I'm not selling anything, and personally, I'm satisfied with any view of the eagle nest that they keep us a long distance from; my binocular-wielding wife was "pretty sure" the eagle was there - I got a photo of the eagle and the 'eagle-cam' above her. A 2X + lens on my newly-acquired KP would be even better.

Best bang for the buck long 300mm tele for Q? - Page 5 - PentaxForums.com

[angerdan]

Is this how the new Pentax Teleconverts could look alike?
KENKO TELEPLUS HD pro 1.4X DGX
KENKO TELEPLUS HD pro 2X DGX
Testing Kenko Teleplus HD DGX 2.0x tele converter in Aeroplane Spotting - a review by Juan Pablo Muñoz

[RonHendriks1966]

Is this how the new Pentax Teleconverts could look alike?
KENKO TELEPLUS HD pro 1.4X DGX
KENKO TELEPLUS HD pro 2X DGX
Testing Kenko Teleplus HD DGX 2.0x tele converter in Aeroplane Spotting - a review by Juan Pablo Muñoz

The Opera 50mm isn't supported, so the Pentax dfa* 50mm maybe also not when this would be worked into a Pentax tc.

[angerdan]

The Opera 50mm isn't supported

The Opera 50 for Canon is supported.

[thibs]

Well not using a TC on a 50mm isn't that much of a loss, is it ?

[biz-engineer]

I've had TC, sold them, buy TC again and sold again. Image comparison of crop vs TC told me that TC is only valuable when the sensor resolution doesn't allow to crop, e.g 24Mpixel instead of 36Mp or 45Mp. AF generally works better without TC, so unless the lens out-resolve the sensor by a good margin TC don't bring anything (get the image on the whole frame and bump iso to compensate for loss of light => no better than cropping of high res. sensor). So, unless Pentax makes a fast 16Mp or 24Mp camera, I'll never get any TC again. TC is great with a 16Mp full frame that boast 10 frames per seconds, OTOH TC on a K1 is a waste

[Reed]

New Kenko TC's are shown on Canon 6D paired with Tokina ATX-Pro 50-135/2.8 lens. Quite weird set, an aps-c lens on FF teleconverter and FF Body.

[thibs]

Well, if it makes the apsc lens cover the FF image...