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02-07-2014, 03:23 PM   #196
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QuoteOriginally posted by baro-nite Quote
So says the literature although there seems to be some debate about whether this is simply because very few shorter FL lenses can fit the L converters. But you're right that it would certainly be interesting to test this with one of the Pentax 300/2.8s or something longer. (I could test with the A400/5.6 but there I think the lens itself is the limiting factor.)
Precisely I'm awaiting this TC to test with both FA*300 f2.8 and FA*600 f4. I'll keep you informed.
I have used these lenses with the old 1,4 XL converter, results were good in terms of sharpness but lack of contrast, HD coatings should give better result.
These old TCs were designed back in the 80s

02-07-2014, 03:28 PM   #197
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QuoteOriginally posted by audiobomber Quote
I thought the S was designed for shorter focal length lenses (under 300mm) and L for longer focal lengths.
The Rear Converter A Manual isn't too clear on this issue, but if I read it correctly, then:
  • The A 1.4X-S shouldn't be used with an FL of 300mm and higher;
  • The A 2X-S can be used with a number of lenses with an FL below 600mm, however
  • The L-types are better optimized for (long) lenses with ED glass (and of course only suited for lenses that will accept the protrusion on this converter type)
See:
http://www.gyes.eu/documents/pentax_rear-converter-a_operating-manual(1990).pdf
02-07-2014, 04:45 PM   #198
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I am very interested in this one... too bad it does not seem to support FA limited, but I would use it with my DA* 16-50 or DA*50-135. The price does not seem to be too bad in Japan, about 49100 Yen; I will check it out when I go to Japan in a month...
02-07-2014, 05:47 PM - 1 Like   #199
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QuoteOriginally posted by aleonx3 Quote
I am very interested in this one... too bad it does not seem to support FA limited, but I would use it with my DA* 16-50 or DA*50-135. The price does not seem to be too bad in Japan, about 49100 Yen; I will check it out when I go to Japan in a month...
I wonder, why would one use 1.4x converter on a 31mm lens?
Or on a 43mm lens? For what exact purpose?

Like you don't already have the lenses that reach beyond 1.4 x 43mm?

This whole whinging euphoria about whether the TC works with FA limiteds, or kit zooms, only shows that many have totally lost the plot.

02-07-2014, 05:55 PM   #200
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QuoteOriginally posted by Uluru Quote
I wonder, why would one use 1.4x converter on a 31mm lens?
Or on a 43mm lens? For what exact purpose?

Like you don't already have the lenses that reach beyond 1.4 x 43mm?

This whole whinging euphoria about whether the TC works with FA limiteds, or kit zooms, only shows that many have totally lost the plot.
Agree with you on that one, except there were a few times in the past that I only carry the three "amigos" when I am travelling. I use my DA* lenses mostly for my stage photography when not traveling.

Last edited by aleonx3; 02-07-2014 at 07:20 PM.
02-07-2014, 10:49 PM   #201
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QuoteOriginally posted by Uluru Quote
I wonder, why would one use 1.4x converter on a 31mm lens?
Or on a 43mm lens? For what exact purpose?
I can only come up with one reason for this--because they can...

I certainly wouldn't go out of my way to buy the TC just to use for the 31mm or 43mm.
02-08-2014, 07:24 AM   #202
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QuoteOriginally posted by Uluru Quote
I wonder, why would one use 1.4x converter on a 31mm lens?
Or on a 43mm lens? For what exact purpose?
It doesn't say that they don't work... so maybe they just forgot to mention them? FA77 + converter could perhaps make some sense - would give a quite fast and light 105mm lens...
02-08-2014, 07:54 AM   #203
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QuoteOriginally posted by gazonk Quote
It doesn't say that they don't work... so maybe they just forgot to mention them? FA77 + converter could perhaps make some sense - would give a quite fast and light 105mm lens...
The DFA 100mm could be had for cheaper than this TC alone, would be lighter and smaller than the 77+TC combo and would most certainly have better IQ. No matter how good a TC is there is always some image degradation, as slight as it may be.

02-08-2014, 09:24 AM   #204
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QuoteOriginally posted by cali92rs Quote
The DFA 100mm could be had for cheaper than this TC alone, would be lighter and smaller than the 77+TC combo and would most certainly have better IQ. No matter how good a TC is there is always some image degradation, as slight as it may be.
You're missing the point... if you use the 77+ the TC, you can use the 77as a 77, or a 105. That's lighter and more convenient than carrying The 77 and the 100.

I'm in exactly the same situation. I've gotten into the habit of taking my DA*60-250 and my A-400. That's a lot of glass. If I take my DA*60-250 and a TC, I can sell the A-400 and have the same reach and quality, and half the weight. Essentially every lens becomes two lenses. And I'm not convinced my 60-250 and TC gives me less IQ than my A-400, my experience isn't supporting your notion.

I'm really opposed to this idea
QuoteQuote:
No matter how good a TC is there is always some image degradation, as slight as it may be.
A TC adds another 5 elements to a lens, so you're saying a 7 element lens isn't as good as 12 element lens? I'm not un-aware as to the possible conflicts of adding to a lens that's already complete, but I'm not convinced a TC automatically reduces image quality.

With a good lens like our Tamron 90 or DA* 60-250 we don't notice image degradation, if you don't believe me go back up the page and look at the examples I posted, one with a TC, one with a prime. IN fact we love the results we get using a TC with a Macro, definitely more detail in the macro than shooting without the TC, that's not even open to speculation.

Or have a look at this, a 1:1 pixel peeper taken with the Tamron 90 and the Pentax 1.7 TC.


The case that a TC degrades your image really hasn't been made to my knowledge. I've heard many people say it, I've never seen anyone back it up with examples, and all the examples I've produced say it's not true, at least not for people using quality lenses. If you use a lens that's soft, obviously you'll just magnify the softness.

I think perhaps it's possible that people don't realize that when they take their 100mm lens and make it a 170mm, there's a whole new level of image stabilization that has to go with that. It's not that they can't take as good images, it's that they naively believe they can shoot with a 170mm lens the same way they could when it was a 100mm lens.

Last edited by normhead; 02-08-2014 at 09:39 AM.
02-08-2014, 10:25 AM   #205
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QuoteOriginally posted by normhead Quote
You're missing the point... if you use the 77+ the TC, you can use the 77as a 77, or a 105. That's lighter and more convenient than carrying The 77 and the 100.

I'm in exactly the same situation. I've gotten into the habit of taking my DA*60-250 and my A-400. That's a lot of glass. If I take my DA*60-250 and a TC, I can sell the A-400 and have the same reach and quality, and half the weight. Essentially every lens becomes two lenses. And I'm not convinced my 60-250 and TC gives me less IQ than my A-400, my experience isn't supporting your notion.

I'm really opposed to this idea


A TC adds another 5 elements to a lens, so you're saying a 7 element lens isn't as good as 12 element lens? I'm not un-aware as to the possible conflicts of adding to a lens that's already complete, but I'm not convinced a TC automatically reduces image quality.

With a good lens like our Tamron 90 or DA* 60-250 we don't notice image degradation, if you don't believe me go back up the page and look at the examples I posted, one with a TC, one with a prime. IN fact we love the results we get using a TC with a Macro, definitely more detail in the macro than shooting without the TC, that's not even open to speculation.

Or have a look at this, a 1:1 pixel peeper taken with the Tamron 90 and the Pentax 1.7 TC.


The case that a TC degrades your image really hasn't been made to my knowledge. I've heard many people say it, I've never seen anyone back it up with examples, and all the examples I've produced say it's not true, at least not for people using quality lenses. If you use a lens that's soft, obviously you'll just magnify the softness.

I think perhaps it's possible that people don't realize that when they take their 100mm lens and make it a 170mm, there's a whole new level of image stabilization that has to go with that. It's not that they can't take as good images, it's that they naively believe they can shoot with a 170mm lens the same way they could when it was a 100mm lens.
People have actually run tests and have shown that with a 1.4x TC, you lose about 5% sharpness. Of course you wouldn't notice that unless you were looking at images 100%, but its there whether or not you want to admit it.
Also, the field of view between 77mm and 105mm is so small, how is it more convenient? You see a bird, you quickly remove your 77, slap on a TC, then the 77, then take your shot.
In the case of carrying both the 60-250 and the 400, that is much different and thats when a TC makes sense.

And that sample you shown does not prove anything. The NR applied just wipes out any detail you were trying to show.
02-08-2014, 10:34 AM   #206
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QuoteOriginally posted by cali92rs Quote
People have actually run tests and have shown that with a 1.4x TC, you lose about 5% sharpness. Of course you wouldn't notice that unless you were looking at images 100%, but its there whether or not you want to admit it.
Also, the field of view between 77mm and 105mm is so small, how is it more convenient? You see a bird, you quickly remove your 77, slap on a TC, then the 77, then take your shot.
In the case of carrying both the 60-250 and the 400, that is much different and thats when a TC makes sense.

And that sample you shown does not prove anything. The NR applied just wipes out any detail you were trying to show.

Ya, I've seen some tests I haven't been able to replicate... so what you're saying is that using an MTF chart, you will get 5% less resolution over the subject than not using the teleconverter? I don't think so, sources please. I've got my pictures, so far you've got nothing. I'm willing to believe you won't get as much resolution over the whole image.. and my A-400 doesn't resolve as much as my DA*60-250, lenses tend to lose resolution as they get longer, with or without a teleconverter involved, so without being able to see what folks have done so I understand their methodology, I'm not buying it.
02-08-2014, 10:55 AM   #207
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QuoteOriginally posted by normhead Quote
Ya, I've seen some tests I haven't been able to replicate... so what you're saying is that using an MTF chart, you will get 5% less resolution over the subject than not using the teleconverter? I don't think so, sources please. I've got my pictures, so far you've got nothing. I'm willing to believe you won't get as much resolution over the whole image.. and my A-400 doesn't resolve as much as my DA*60-250, lenses tend to lose resolution as they get longer, with or without a teleconverter involved, so without being able to see what folks have done so I understand their methodology, I'm not buying it.
Typical response by you.... you dont understand something so you say its not true. Then someone shows you a test and you say they didnt test the way you would've tested so its not true. Or that it doesnt matter because it doesnt show up in real life. It's the standard template post for you.
I wouldn't care because you will buy whatever you want. But someone new to photography may unnecessarily spend a lot of money because of mis-information you spread.
02-08-2014, 11:21 AM   #208
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Oh really? A personal attack, is that the best you can do? I'm disappointed. I was actually thinking you might have something to offer. Sometimes people who say these kinds of things know something I don't and share it. I don't know everything, but I know a lot more than people like you give me credit for.

I frequently notice when people present partial data, they think proves their case, that really has very little to do with the issues being discussed. Then when I point that out, they say I don't understand the issue. it's kind of backwards. I generally see the problems with an approach to testing an issue, and won't buy in until those issues are resolved. It's frustrating to people who want to be experts, but really haven't got a clue what they're talking about, but there's nothing I can do about that. If you want to impress me, know your stuff, do more than read some opinions on the internet, and spit out their conclusions.

That's my take on it. I never give anyone a free pass. And in my experience, real experts know how to respond to that, because they understand what I said, and can respond with an appropriate opinion.

Your above response is not an appropriate opinion. Kind of shoot the messenger, ignore the critique.

Last edited by normhead; 02-08-2014 at 11:31 AM.
02-08-2014, 11:29 AM   #209
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I can crop DA*300 images to 100% using the Kenko PZ 1.5X TC, and still have acceptable sharpness. I was not able to do that with the Pentax A 2X-S. I had better results cropping with the Kenko to the same magnification as the 2X-S, so I stopped using the Pentax TC.
02-08-2014, 01:19 PM   #210
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OK here's exactly what I'm talking about. imported raw files same processing...

Tamron 90 image


Tamron 90 with TC


Tamron 90 expanded in pixelmator to be the same size as the TC image.


To my mind the most detailed image of the 3 is the 90 with TC. This exactly illustrates my point.
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