[UserAccessDenied]

I have often though OS selling my 50-500 and just getting a DA*300 instead.

exactly what I did.
would do it again too. DA*300 is spectacular, just wish it was 500mm.

[Scorpio71GR]

exactly what I did.
would do it again too. DA*300 is spectacular, just wish it was 500mm.

Many people say the 50-500 is more like 450mm at 500. So it really may not be that far off the DA 300 plus TC combo. If I were to replace my 50-500 it most likely would be with the 150-450.

[BigMackCam]

Just curious, who in the UK sells and ships at this price to USA?
Is there a preferred site?

Thanks!

SRS Microsystems is one of my favourite suppliers here. They currently have it at £259, and I'm certain they'll supply to the US. Here's the link:

Pentax HD PENTAX-DA AF Rear Converter 1.4X AW

[noelpolar]

That is a good price.... no supply to Australia though!

[Scorpio71GR]

That is is great price, delivery is just to UK and EU though.

[normhead]

I use that TC, its branded Vivitar( apparently a Kenko design)....its good but no WR....price is GREAT!...


And it goes well with the Sigma 135-400mm....this combo will cost half the price of a DA 1.4x and give a great range....560mm on K1 or 840mm on crop.

But not WR.

[Scorpio71GR]

But not WR.

Also it does not communicate focal length or apeture to the camera. This essentially cripples the SR reduction system by setting for the wrong focal length. I pretty much only use my Tamron TC when on a tripod and SR is jot needed. I plan on getting the Pentax TC eventually. I would get it sooner if I had more f2.8 lenses to mount it on.

[Shanti]

I wish I had the first hand experience to say yay or nay.

Same again


I believe the 300 and 1.4 is hand holdable if you're reasonably well built, the 560 not so much...

yes I have the DA*300 + 1.4 TC and no problem to handhold..also the AF 1.7 TC works well on the 300..& a bit more reach..make to to fine adjust the AF though

[Cthulhugan]

How much different is 500mm from 420mm?

420 is 84% of 500, so objects shot at 420 will be 84% of the size they would have been if shot at 500. 420 is about 77% of 560. That might be easier to visualize than angle of view.

[normhead]

The 1.7x on the 300 is 510.

[UserAccessDenied]

The 1.7x on the 300 is 510.

I just purchased the 1.4x HD TC.
If I can find a 1.7x later on for a good price I might pick one up just to do a comparison using the DA*300.

I know the 1.7x will hinder AF a bit. But using it to act almost like a focus limiter would be kind of cool I think - Manually focus to the range and use the tc to fine adjust on the subject.

I love the idea of a full WR 420mm f5.6 on my K-3ii.

[ivanvernon]

I recently acquired a Kiron MC7 2X Teleconverter for Pentax mount. I have not begun using it, but I have a question and would appreciate comments. The question is whether using a teleconverter does/should provide better results than simply cropping to increase image size. I have heard pronouncements on both sides of this question. I am sure the quality of the teleconverter glass makes a difference but wondering what other variables are at work.

[THoog]

I know the 1.7x will hinder AF a bit. But using it to act almost like a focus limiter would be kind of cool I think - Manually focus to the range and use the tc to fine adjust on the subject.

I was going to mention the F 1.7x. I can shoot it handheld on the DA*300. Focusing is kind of hybrid MF/AF - kind of like using quick-shift to get close, then AF to get a lock. It's not the fastest method if you are doing a lot of tracking shots, but it works well enough for zoopix.

[surfar]

Also it does not communicate focal length or apeture to the camera

Mine does.

[THoog]

I recently acquired a Kiron MC7 2X Teleconverter for Pentax mount. I have not begun using it, but I have a question and would appreciate comments. The question is whether using a teleconverter does/should provide better results than simply cropping to increase image size. I have heard pronouncements on both sides of this question. I am sure the quality of the teleconverter glass makes a difference but wondering what other variables are at work.

I've tried a number of TCs over the years, and I've found success is a combination of three things:

1) Quality of the primary lens. A lot of people (myself included, 20 years ago) think you can put a TC on a consumer zoom and get a longer consumer zoom. It rarely works that way. The host lens has to have enough resolution that IQ is not lost when you enlarge the image with the TC. I had pretty much given up on TCs because all I got was mush until I tried one on a "star" lens.
2) Quality of the teleconverter. There's a reason why the good ones cost hundreds of dollars. Most 2x TCs (emphasis on most) take a huge hit to IQ along with the 2 stops of light lost, and you are better off with a digital crop, especially if you have a higher-resolution sensor. It's more "it depends" with 1.4x and 1.5x TCs.
3) Quality of the light. When you are losing 1-2 stops of light, unless you have a really fast primary lens, you are going to bang into some kind of limit, whether it be having a fast enough shutter speed for the focal length or noise from having to use high ISO. You can't just slap the TC on for more reach - lighting conditions that were "good enough" for the primary lens may not be for the combination.