[redpit]

Of course the HD DA 1.4tc works, and even seems to work well with certain lenses. But mostly as a cost effective way to get reach on the K1 with e.g. a 200mm or 300mm lens. When you get to the 400+ - 560mm of the FF compatible DA150-450 or DA560, you have to crop so significantly, that it compromises the versatility, and you might as well use an apsc crop camera.

Chris

Exactly that is the case. I'm feeling too that a FF TC will be one of Ricoh-Pentax priorities.

[Kunzite]

So, you want an D FA 1.4 because the HD DA works so good?

Sigh... I want a D FA 1.4x RC so I won't have to crop every single picture taken with the D FA 150-450 and the 1.4x RC. I already said that.
And after all, it's not your d*mn business.

[normhead]

Well then, explain your self a bit and we won't have this issue. All you had to do to clarify this was say your problem was confined to the 150-450. So what you want is not an FF compatible 1.4 TC, what you want is a 150-450 compatible 1.4 TC and also mentioned is the 560 I believe?

TCs tend to be better or worse, on certain lenses... and in your mind, that translates to "Pentax doesn't have an FF TC." Thanks for clarifying that normhead. Because of the sloppy language used used and the way the concepts were presented, some could have assumed there is no FF compatible TC." And in your dreams you are imagining a TC specifically for 2 lenses that isn't needed anywhere else.

And ya, if you throw something you in a public forum, that's misleading and I read it, it is my business as part of the public. If that bothers you, keep your half formed ill presented thoughts in the privacy of your own home and we won't have an issue.

You really need to understand. Just because it's going round and round in your head doesn't mean anyone else knows what you are talking about, even though it's obvious to you.Your assertion that Pentax doesn't have a TC compatible with it's lenses non-sense. As I demonstrated. The same set-up attached to a K-1 is depressingly short. There are solutions, you just don't like them,

I guess you guys just never heard of "crop factor"

That they might need a special TC for lenses like the 150-450 and 560, has nothing to do with FF or APS;c. It's about those two lenses.

But you have made me vary happy I bought the Tammy 300 for my K-1 instead of the D FA 150-450. With the 1.7 the Tammy gives me 510, and at the moment, I use it every time I go to the blind.

My solution to this was 300 2.8 with 1.7 for 510mm on my K-3 giving me 24 MP and the equivalent of 750mm. But then I tend to just get things done, and not sit around thing about imagined products Pentax should make.

[GeneV]

It would be nice to have a TC which was better compatible with FF. Granted, some do work on some lenses. However we have lenses such as the DA*300, which works very well on the K1 without the TC, but with it, not so well, as seen below. We have so few FF digital primes, that a TC which gets the best out of all the primes which do work would be greatly appreciated.

Attached Images

View Picture EXIF

File Date

 

[Kunzite]

Norm, you are irrelevant to me and I am not asking for your advice; I've made my request known - on this forum and to Ricoh Imaging and I'm willing to back it up with my money. That's all that matters.

By the way; Pentax doesn't have many FF long lenses in the current lens line - only the D FA* 70-200, the DA* 200 f/2.8, the DA* 300 f/4, the D FA 150-450 f/3.5-5.6 and the DA 560mm. I'm being generous including the (up to) 200mm lenses. If you haven't tried them all except the 150-450mm, you cannot claim the issue is confined to that specific lens.
I remember reports on vignetting with the DA* 300mm f/4 as well. Just curious, how many example are required to call it an APS-C converter?

L.E. Gene, thanks for the example.

[Ron_Man]

I honestly would prefer that Pentax actually design and manufacture their own lenses... if they wanna compete with the big boys they should play like the big boys..

[normhead]

A-400 image on K-1 with 1.4 TC

Cropped to

Cropped to remove vignetting, its about 24 MP, K-3 size with less magnification.




K-3 with same lens set up...


Why would anyone use a K-1 for such an image? The K-3 gives you more subject magnification and virtually the same MP if you consider the crop.

My long lenses for the most part stay on my K-3, unless the subject is close enough I won't have to crop. As Pentax themselves say, the K-1 is a "field" camera. Great for landscapes etc.. I get the feeling what's going on here is some folks are thinking "I wish my K-1 would do what my K-3 can do." For folks like myself who advise folks to think about what they are giving up before they switch formats, that's just sad. Personally, I don't switch formats, I add formats.

Personally, Pentax being the small company that it is, I wonder if they will ever come out with a TC for their longer lenses, especially since it isn't needed for the shorter ones. A matched TC for the 300, 150-450 and 560 would be a real specialty item.

Tamron SP AF 300mm ƒ2.8 ED [IF] with F1.7x AF Adapter uncropped. There is a tiny little bit of vignetting top left.



The question here is, my Tamron uses the 1.4 and 1.7 virtually flawlessly on the K-1. Is the design of the DA*300, D FA 150-450 an DA 560 such that it isn't even possible to design a TC for them? Clearly the lens design is a factor here.

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Last edited by normhead; 11-16-2016 at 10:00 AM.

[redpit]

It is a fact that the current DA 1.4X TC is compatible with the K-1 as it is a fact that it is not a FF TC as it heavily vignettes with many longer lenses rendering them not FF anymore as you need to crop the image to make it usable. Pentax knows that so when the DA 1.4X TC is mounted on the K-1 it automatically switches to crop mode.

Pentax representatives have revealed that even before K-1 hit the selves:

You Tube

You Tube

Watch the question-answer at 2:53 of the video.

And also we have tested it with our longer Pentax lenses that are FF (like @GeneV with the DA* 300/4 above) and the DFA 150-450 and it can't provide a usable FF image.

https://www.pentaxforums.com/forums/190-pentax-k-1/314413-post-your-k-1-pictu...ml#post3634452

I'm sure that when Pentax releases its next lond tele or super tele lens (I hope soon) it will also release a DFA 1.4X TC and why not a 2.0X too.

[Kunzite]

normhead just contradicted himself, first claiming the vignetting is confined to the 150-450, then proving that it's there with the A 400mm, too.
You cannot discuss with such a man.

[normhead]

normhead just contradicted himself, first claiming the vignetting is confined to the 150-450, then proving that it's there with the A 400mm, too.
You cannot discuss with such a man.

As per usual, you throw the baby out with the bath water.

But yes, I have to admit. it never occurred to me that I hadn't used the TC with the K-1 I'd only use the K-1 and TC with the Tammy 300 and assumed it worked the same with my other lenses. Sometimes I make a mistake, but I correct them. You make mistakes all the time, and never fess up.

You cannot discuss with such a man.

---------- Post added 11-16-16 at 12:09 PM ----------

And also we have tested it with our longer Pentax lenses that are FF (like @GeneV with the DA* 300/4 above) and the DFA 150-450 and it can't provide a usable FF image.

I am so glad I bought my Tammy.

I was just walking along in total oblivion to these issues.

I have to agree dudes, that really sucks.

IN the spirit of not throwing the baby out with the bath water.... I repeat.

Tamron SP AF 300mm ƒ2.8 ED [IF] with F1.7x AF Adapter uncropped. There is a tiny little bit of vignetting top left.



The question here is, my Tamron uses the 1.4 and 1.7 virtually flawlessly on the K-1. Is the design of the DA*300, D FA 150-450 an DA 560 such that it isn't even possible to design a TC for them? Clearly the lens design is a factor here.

After all, the fact that the Pentax engineers say the 1.4 doesn't work, doesn't mean there could be one made that does, the possibility of designing a TC for those lenses isn't addressed.

The 560 and 300 are DA lenses, no reason they should work on FF with a TC, but the 150-450? Wat wid dat?

[boriscleto]

Doesn't the DA 560 already vignette at F/5.6 on the K-1?

[Kunzite]

No, it doesn't - at least it's not worse than other comparable lens from the competition.

[normhead]

The biggest problem I see with using a 1.4 converter on a ƒ5.6 lens is you have ƒ8 as your largest aperture. I've said many times, I can use focus assist to manually focus my A-400 ƒ5.6 with the 1.4 but not the 1.7. Compared to putting the 1.4 on a 2.8 or F4 lens, you are already giving up a lot of functionality using a 5.6 lens.

Would Pentax even want to encourage such behaviour, much less specifically design a TC just to make it possible.

Hopefully. people will now stop saying Pentax doesn't make an FF TC , Pentax dioesn't make a TC that works with the 150-450, 300 or 560 on a K-1. But they do make TCs that work with many lenses on a K-1, especially 2.8 full frame lenses. The ones who posted the nonsense in the first place are too proud to come on correct their mis-information... they always leave that to folks like me.

[Kunzite]

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 .

[biz-engineer]

The biggest problem I see with using a 1.4 converter on a ƒ5.6 lens is you have ƒ8 as your largest aperture. I've said many times, I can use focus assist to manually focus my A-400 ƒ5.6 with the 1.4 but not the 1.7. Compared to putting the 1.4 on a 2.8 or F4 lens, you are already giving up a lot of functionality using a 5.6 lens. Would Pentax even want to encourage such behaviour, much less specifically design a TC just to make it possible. Hopefully. people will now stop saying Pentax doesn't make an FF TC , Pentax dioesn't make a TC that works with the 150-450, 300 or 560 on a K-1. But they do make TCs that work with many lenses on a K-1, especially 2.8 full frame lenses. The ones who posted the nonsense in the first place are too proud to come on correct their mis-information... they always leave that to folks like me.

TC on f5.6 lens , + you have to stop down the lens a bit to get more sharpness, typically lead to shooting between f9 (f10, f11) f13, which need a lot of light, or using a flash, which seriously limit suitable shooting conditions. There was a lot of arguing about Tamron/Sigma 150-600 f6.3 being so much better than Pentax offering... but that's a pile of BS. To really get any significant improvement from current Pentax offering, you really have to break the bank and pay spend between 5K and 12K on a lens. Using a Tamron 150-600 (even the G2 that happens to have half stop of transmission loss over the SP version), isn't going to make any difference in shooting versus using Pentax gear. I'm sincerely afraid that Pentax user base is sufficiently weak in long lenses so that some people would swallow some of the arguments brought about in Pentax forum from Canon and Nikon users. That's surfing on the least practically experienced users to lure them into believing in Canikon paradise. Some have acquired a D500 and a 150600 f.63 thanks to the miraculous AF tracking power of the D500...(which is be true at f4 or f2.8) , just to realize that f6.3 isn't sharp, f8 is, pushing the ISO fairly high in order to maintain fast shutter speed and AF tracking not as good as the marketing advertisement when used with slow AF lens. In order words, if you are a Pentaxians and if you really want to get a measurable step up from Pentax, you have to spend $15K (lens + camera of the other brand). Other folks have 600 f4 lenses claim that they use it a F7.1 or smaller aperture because of the DoF being too thin. I can only conclude that using long lenses either require a lot of sun (in this case , using a TC is fine) or flash. Flash and flash extender is way cheaper that getting a fast long lens.

I did some tests with a DFA150450, TC and manual flash to add one or two stops of light , and it really works great, it is a cheap alternative for getting sharp images with 630mm (or 945mm in crop mode).