[normhead]

Except for the D FA 150-450, DA*300 f/4, DA 560mm and other lenses which will be added to the list...
I feel like we're playing in a Monty Python sketch .

I feel like you're playing in a Monty Python sketch. I guess the part where no one's TCs work with every lens they make escaped you. With the DA lenses you have a absolutely no right to expect they would cover an FF image circle at all forget about with a TC. You do understand what a DA designation means, I assume?That leaves the 150-450, with the technical reasons why it should probably never be made. So, really, you've got nothing.

I am curious though, does anyone know if the 1.4 TC works with the 70-200? If it didn't work on a 2.8 lens I'd be scratching my head.

Except you bought a 150-450 expecting to use a TC on it and now are hoping Pentax will bail you out, even though it would probably be a mistake technically, and may even be technically impossible.

How do the TCs work on FF with those 150-600 lenses. Where's Ian when we need him?

Thanks normhead for clarifying the issue here.

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Last edited by normhead; 11-16-2016 at 12:36 PM.

[Kunzite]

Get off your high horse, nobody's thanking you for your nonsense (I know a word for that, starts with 't', but mods would be unhappy if I'll use it)
The DA* 300mm f/4 is a full frame lens - Ricoh Imaging says so. You might not believe it, but they know better than you. They sort of made that lens.
Anyway, it's interesting to see how you're so aggressively saying that the DA 1.4x RC is a full frame teleconverter, and at the same time you're saying the DA* 300mm f/4 is an APS-C lens because it's named 'DA'...

[biz-engineer]

That leaves the 150-450, with the technical reasons why it should probably never be made.

Yes, and no. A lot of people buy the telezooms for birding because they are more affordable than long primes. Technically, the 100-500 FF zooms are design for photography of safari, airplanes, motorsports and they are advertised as such. Those zooms aren't designed for birding, that doesn't prevent that they are often the first long lens that people buy (wrongly) for taking photos of birds.

I am curious though, does anyone know if the 1.4 TC works with the 70-200? If it didn't work on a 2.8 lens I'd be scratching my head.

Yes, curiously, the DFA70-200 work very well with the DA TC, no vignetting at all. I guess what causes the vignetting is the angle of light projection from the exit of the lens to the TC, hence vignetting with TC added, varies depending of what lens is used.

---------- Post added 16-11-16 at 21:15 ----------

How do the TCs work on FF with those 150-600 lenses. Where's Ian when we need him?

According to Matt Granger who tried the Tamron 150-600 G2 with the TC also sold by tamron, focus is manual, and when using the 2xTC, image quality is barely usable for 1080p video.

[Kunzite]

I guess we need an optical engineer if we want to get an answer.
If we could approximate the lens as a simple lens, a 300 f/4 would have a larger diameter than a 200 f/2.8. But that sounds too easy, thus I'm doubtful it's the correct approach.

[FantasticMrFox]

I feel like you're playing in a Monty Python sketch. I guess the part where no one's TCs work with every lens they make escaped you. With the DA lenses you have a absolutely no right to expect they would cover an FF image circle at all forget about with a TC. You do understand what a DA designation means, I assume?

The DA designation was introduced at a time where Pentax did not have any digital full-frame camera. Ricoh has stated the DA* 300 and DA 560 are full frame lenses - officially. So yeah, he does have a right to expect them to cover the full image circle.

[normhead]

Get off your high horse, nobody's thanking you for your nonsense (I know a word for that, starts with 't', but mods would be unhappy if I'll use it)
The DA* 300mm f/4 is a full frame lens - Ricoh Imaging says so. You might not believe it, but they know better than you. They sort of made that lens.
Anyway, it's interesting to see how you're so aggressively saying that the DA 1.4x RC is a full frame teleconverter, and at the same time you're saying the DA* 300mm f/4 is an APS-C lens because it's named 'DA'...

The DA* 300mm f/4 is a full frame lens

Anyway, it's interesting to see how you're so aggressively saying that the DA 1.4x RC is a full frame teleconverter,

Your word not mine, I just said it works with many full frame lenses, which it does. But if it works on some FF lenses does that not make it an FF TC?

Read up...

"SMC Pentax-DA" and "SMC Pentax-D-FA" -
Current series AF lenses that support every DSLR feature. DA series are optimized for the 16x24 sensor format, D-FA series also include image circle for the 35mm film SLR format. DA series lense do not have aperture rings (aperture control is through the body exclusively).

What do the various Pentax lens designations mean? - Photo.net Mirrorless Digital Cameras Forum

Do you have a source?

WhIle I'm quite aware that many DA lenses are derived from older FA designs, and may have some FF compatibility, there is a difference between FA and DA., and D FA lenses.

But I have to ask, if the DA 300 is fully FF compatible, why does it vignette on a TC? Or does FF compatibility have nothing to do with TCs. IN which case why would you expect your 150-450 to work with a TC?

At this point, I'm just pointing out your endless inconsistencies dude. We should probably just let it go? You can have the last word if you choose.

My advice remains, if you're waiting for Pentax to release a TC compatible with your 150-450, it may not be economically possible to produce this TC, it may not be technically possible to produce this TC, and the TC may function so poorly if actually designed in terms of maximum aperture, you may wish they didn't even if they make one you can buy.

All I'm saying is, don't hold your breath.

es, curiously, the DFA70-200 work very well with the DA TC, no vignetting at all. I guess what causes the vignetting is the angle of light projection from the exit of the lens to the TC, hence vignetting with TC added, varies depending of what lens is used.

Exactly my thoughts on the matter.

According to Matt Granger who tried the Tamron 150-600 G2 with the TC also sold by tamron, focus is manual, and when using the 2xTC, image quality is barely usable for 1080p video.

Same conclusion I came to with the A-400 and 1.7.

My two year journey that ended up with two 2.8 telephotos was based on using the shortest lens possible to give me the lightest, smallest possible telephoto package for hiking and canoe trips. The thing Pentax needs to do right now is not a 1.4 TC for the 150-450, but a 2X converter for the 70-200. A couple of my buddies use this on Canon, it gives them 400 5.6 with Canon AF, and because Canon does it, we know it should be technically possible.

Does anyone make a 1.4 TC that works fully functionally on a 5.6 lens and full frame?

[Kunzite]

My source is Ricoh Imaging. For example, here:
http://www.ricoh-imaging.co.jp/japan/products/lens/images/K_Mount_Lens.pdf
you can see the "DA lenses which covers 35mm full-frame image circle" section on page 2.
Guess what's not on this section... yep, the 1.4x RC (which appears on the previous page).

The DA* 300mm f/4 might not have such vignetting with a FF teleconverter (Barry Pearson made some tests on film, with a Kenko: http://www.barrypearson.co.uk/articles/pentax/ff-300.htm; also check this: https://www.pentaxforums.com/forums/190-pentax-k-1/321600-ff-teleconverter-k-...ml#post3678323)

AdrianM posted an image with the D FA 150-450mm and a 1.7x ProMaster teleconverter:
https://www.pentaxforums.com/forums/190-pentax-k-1/321600-ff-teleconverter-k-...ml#post3740577
and with a Tamron 1.4x teleconverter:
https://www.pentaxforums.com/forums/190-pentax-k-1/321600-ff-teleconverter-k-...ml#post3650499

Your advice is that we should not even dare asking for a D FA rear converter, or you'd get upset.

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Last edited by Kunzite; 11-16-2016 at 02:02 PM.

[asahi man]

The DA*300 also is public patented as a 35mm lens and has no FA brother.
It's a complete new development.
The converter is the 3 version of the prototype ,first showed at Photokina together with K-7 prototype.
It was developed short time before Hoya era.
Than there was a second one,same lens system,new body.
But stopped by Hoya.
Short time before Ricoh sets the signal to fullframe free ride,the converter started to the sale.
And it's an APS-C development with the problem of a plan front lens and a little bit to small rear lens.
Best regards

[Ian Stuart Forsyth]

How do the TCs work on FF with those 150-600 lenses. Where's Ian when we need him?

Works perfectly fine , the sigma sport along with the new sigma 1.4 AF handheld right in the store with no problem, I was sold right then and there.
I don't see anything along the lines of any great vignette that would draw my attention to it when used on the 150-600

[Dan Rentea]

Does anyone make a 1.4 TC that works fully functionally on a 5.6 lens and full frame?

Yes, Canon and Nikon does.

- the 100-400mm f4.5-5.6L IS USM lens (the one that you thought is an APS-C lens ) works quite good with 1.4x TC. At f8 you have good Af on a few bodies (5Ds, 5D Mark IV, 1Dx, 1Dx Mark II). Mounted on the 6D the Af is decent, only with the center point.
- the 200-500mm f5.6E ED VR also works quite good with 1.4x TC, with good Af on a few bodies (D810, D750, Df, D4s, D5).

Biz-engineer, no one said that Sigma/Tamron 150-600mm are better optically than Pentax 150-450mm. Read that specific topic from the begining. Those lenses gives you the reach of the Pentax 150-450mm + 1.4x TC, at an aperture of f6.3, that's all.

[Ian Stuart Forsyth]

Biz-engineer, no one said that Sigma/Tamron 150-600mm are better optically than Pentax 150-450mm. Read that topic from the begining. Those lenses gives you the reach of the Pentax 150-450mm + 1.4x TC, at an aperture of f6.3, that's all.

I know this, that the sigma sport is not as sharp as the sigma 300 F/2.8 but once you add a 1.4 tc to the 300f2.8 the sigma sport pull ahead when the 2 tc is add to the 300 2.8 the sigma sport beats it by a large margin

[Dan Rentea]

I know this, that the sigma sport is not as sharp as the sigma 300 F/2.8 but once you add a 1.4 tc to the 300f2.8 the sigma sport pull ahead when the 2 tc is add to the 300 2.8 the sigma sport beats it by a large margin

Be careful with this statement. Normhead does not take these kind of news very well.

[surfar]

Barry Pearson made some tests on film, with a Kenko:

a Tamron 1.4x teleconverter:

These are probably the same, mine has Vivitar written on it.....Kenko made it Tamron/Vivitar/Promaster ect rebadged it.


Works on K1, but I don't own dfa150/450 or DA300(so cant comment on these)

[normhead]

Works perfectly fine , the sigma sport along with the new sigma 1.4 AF handheld right in the store with no problem, I was sold right then and there.
I don't see anything along the lines of any great vignette that would draw my attention to it when used on the 150-600

That's a serious disadvantage for the 150-450. A big heavy lens with a shorter focal length than the competitors... and with out the same functionality it's competitors have. People keep going on about how wonderful and experienced this design team is... to me, this looks like a botched assignment.

A question for the Pentax design team.

What was the trade off for making the 150-450 unuseable with a TC... did we get something for it, or did you just mess up?

---------- Post added 11-17-16 at 08:23 AM ----------

My source is Ricoh Imaging. For example, here:
http://www.ricoh-imaging.co.jp/japan/products/lens/images/K_Mount_Lens.pdf
you can see the "DA lenses which covers 35mm full-frame image circle" section on page 2.
Guess what's not on this section... yep, the 1.4x RC (which appears on the previous page).

I checked the Pentax site myself. No where does it claim the DA 300 is a full frame lens, it's a DA lens that has an image circle big enough to cover the FF circle, but apparently, only if you don't use a TC.

The 150-450 on the other hand is an D FA lens... must have been labelled by someone who didn't understand Pentax lens designation. If they had labelled it a DA capable of covering the FF image circle (like many other Pentax DA lenses), I wouldn't be at all critical of it's performance, and I think people would have understood exactly what they were getting.

But it's all moot to me really. I won't carry a lens that big.

[Kunzite]

The Sigma 150-600mm Sports is large and heavy - larger and heavier than the Contemporary version and, of course, than the Pentax 150-450.
It's also expensive, not as much as the Pentax but not too far either.

Besides, the 300mm f/2.8 might not work very well with that TC

---------- Post added 17-11-16 at 03:58 PM ----------

I checked the Pentax site myself. No where does it claim the DA 300 is a full frame lens, it's a DA lens that has an image circle big enough to cover the FF circle, but apparently, only if you don't use a TC.

This is a very difficult question: what is the difference between a full frame lens and a lens which covers the full frame format?