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05-14-2020, 01:18 PM - 1 Like   #166
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QuoteOriginally posted by Serkevan Quote
If it's the images of the front elements, that's... less than scientific . Light transmittance and reflectivity are whack; for example I could make the D FA 28-105 look substantially worse than any of the pictures there with very slight angle variations. There aren't any images where the flare is prominent; a practical head-to-head test against the sun (or a static light source, to avoid angle variations during set up times) there would be great.


(In any case, it's obvious that the HD coating is very good, but it would be great to have definite proof that it's better, if only to kick some naysayers down a notch )
I had this argument on DPR.
Yes, in theory you could influence the result in such a manner; but!
- there are two images presented, both showing the same thing
- the text conclusion is saying the same, and we have no reason to suspect it's solely based on those two images (nor that they only took two images!)
- there just is some extra clarity, if you look through the lens elements at the internal components of the lens. Without a strong light source (particularly in the first image) that IMO cannot be explained by a slight angle variation.

The result looks similar to the "standard multicoated vs. HD" comparison done by Ricoh at Photokina 2012:
https://www.pentaxforums.com/content/uploads/files/1/p603/IMGP0306.JPG
Yes, I've seen that with my own eyes and there was a clear difference.

05-14-2020, 01:53 PM - 1 Like   #167
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QuoteOriginally posted by Serkevan Quote
I guess you're under embargo about it?
Alas, yes.
I wouldn't risk someone to be fired those days.
05-14-2020, 02:31 PM - 1 Like   #168
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QuoteQuote:
Not sure what the Pentax older 250-600 options have to do with anything. They aren't 7000 on eBay. I've been looking. Seem to be between 2500 and 4000.
I've seen pristine copies go as high as $8000 but I haven't looked recently so maybe the prices have fallen, the one I bid on 8 years ago up here went for over $7000, an old RCMP lens. If there was ever a functional one for $2500 5 years ago, I'd own one. The ones you've been looking at must have been in pretty bad shape.

QuoteQuote:
In neither case did I feel that the results with TC beat cropping. But that's my opinion only. And I don't have a 600 to compare
.
Understanding folks saying a TC doesn't ad more detail. - PentaxForums.com
The images are reposted on page 3 of the thread.
My first series of images went as follows... taken at about 40 feet, with not a lot of detail in the test subject.
DA*200


DA*200 plus 1.4


DA*200 plus 1.7


DA*200 by itself enlarged to the same size as the DA*200 2.8 plus 1.7x AF Adapter


Yes you can take images that don't show a difference, but I've posted how you can find out what the difference is. I've never tested a lens where the TC made no difference except for an old bargain basement Vivitar M135 2.8, which is a really bad lens.

My first 55-300 PLM broke in half after a drop. My DA*60-250 was repairable after two such drops. The current cost of my DA 55-300 PLM is about $900. Value priced for some but not for me. One more drop and it will have cost me DA*60-250 money. (But it's worth if for the light weight.)

Pentax recently released a 70-210 that will undoubtedly poach sales form the DA*60-250. So, I'm just not buying it. As for the 600 FL, that is also covered by the DA 560, also a 5.6 lens that can be pushed to almost 800 ƒ8.

That's what's real. Your list of probablies demonstrates your own biases, not much more.

QuoteQuote:
So while I personally would like a Pentax equivalent to the Tamron or Sigma, I just can't see them doing it.
You want a Pentax equivalent to 3rd party cost cutters? I'm with you on that but it's unreasonable. Pentax is an OEM. Tamron and Sigma can't make money selling to Pentax customers at the same prices they sell other brands too. But for some reason people think Pentax should be able too. An OEM building for 3rd party manufacturer prices when even the third party guys can't survive in the Pentax market.

But the big reason in my mind Pentax won't compete with them.. as I said (and you ignored) Pentax will not build a 6.3 lenses except under dire circumstances where it's mechanically necessary. And there are very sound AF reasons of doing that. That's the most likely reason. Even their old 250-600 was 5.6. You could argue, and I frequently do, there's one reason for using 6.3 lenses, you can't afford better. The physical limitations of such glass make them less than desirable.

At 600mm the Tamron 150-600 MTF is terrible.


Now look at the 150-450 Chart at 450


And the Tamron values


Given the Tamron 150-600 values at 600 and the Pentax TC estimated resolution loss of 3% it is very unlikely the Tamron can mach the DA 150-450 with the TC.

My probabilities have a lot more numbers to support them.

Despite the incessant chatter about why can't Pentax compete, it's quite probable that the simple reason is, they don' want to, they don't want the Pentax name on that quality of lens even in the current market, and they currently have covered the focal length with the 150-450 and the TC, and the DA 560.. Anyone who has followed the DA 55-300 PLM, which was immediately branded "top of class" by several different websites understands that.

Pentax cut off the zoom on this lens while it still had excellent or near excleentvalues in 3 of 5 categories. Tamron extended the front element a little further and tanked their lens performance at the long end. It's just not a Pentax type of choice.

I'm going to pull a trick out of your hat, and throw out a probably.
If Pentax had designed the 150-450 by extending the front element so that they achieved 600mm (and ƒ6.3), it would still have been better than the Tamron, but Pentax gave you the opportunity to use the TC, and do better, for more money. Because it was the better option optically, even though it doesn't have the wow marketing effect that can pry sales away from OEMs, not the 3rd party price reducing (but loss of value option.) Because that's what OEMs do.

The Tamron lenses that Pentax rebrands these days (20 years ago with my rebranded Tamron 28-200 that wasn't the case.) are defined to compete optically. The old style, big range big number lower quality lenses (like the 28-200 was), I think Pentax learned their lesson. Selling low end options (like that Tamron at 600mm) doesn't play well for the brand, and in the end produces dissatisfied customers.

Last edited by normhead; 05-14-2020 at 02:49 PM.
05-14-2020, 02:31 PM   #169
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QuoteOriginally posted by Kunzite Quote
That isn't true everywhere in the world.
Just like the price difference as seen in Europe isn't the same everywhere else.
You are right. That is true of the US. I am not sure about other countries.

05-14-2020, 03:34 PM   #170
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QuoteOriginally posted by normhead Quote

.
Understanding folks saying a TC doesn't ad more detail. - PentaxForums.com
The images are reposted on page 3 of the thread.
My first series of images went as follows... taken at about 40 feet, with not a lot of detail in the test subject.
DA*200


DA*200 plus 1.4


DA*200 plus 1.7


DA*200 by itself enlarged to the same size as the DA*200 2.8 plus 1.7x AF Adapter


Yes you can take images that don't show a difference, but I've posted how you can find out what the difference is. I've never tested a lens where the TC made no difference except for an old bargain basement Vivitar M135 2.8, which is a really bad lens.

My probabilities have a lot more numbers to support them.
Photo proof.... Love it Norm. Thanks for those.
05-14-2020, 04:01 PM - 1 Like   #171
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QuoteOriginally posted by OoKU Quote
part right.
Sweet new limiteds
05-14-2020, 06:29 PM   #172
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QuoteOriginally posted by gatorguy Quote
Photo proof.... Love it Norm. Thanks for those.
Your welcome. Now one of these day I'll try and find all the images for the whole post and replace them. That's photobucket doing it's thing.

Last edited by normhead; 05-15-2020 at 07:07 AM.
05-14-2020, 06:53 PM - 1 Like   #173
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QuoteOriginally posted by Ascencio Quote
Sweet new limiteds
sweet.

05-14-2020, 07:49 PM   #174
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So, less than 15 minutes to go and no link to video or anything?
05-14-2020, 08:01 PM   #175
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QuoteOriginally posted by rpjallan Quote
So, less than 15 minutes to go and no link to video or anything?

There is a link in the OP...
05-14-2020, 08:02 PM - 1 Like   #176
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Video is here...



CP+2020 | RICOH IMAGING
05-14-2020, 08:04 PM   #177
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QuoteOriginally posted by OoKU Quote
Guess~
HD Pentax-D FA43/1.9 Limited WR DC

QuoteOriginally posted by Ascencio Quote
Sweet new limiteds
QuoteOriginally posted by OoKU Quote
sweet.
So there you have it. A new Limited but I missed on the focal length.

Last edited by monochrome; 05-14-2020 at 08:12 PM.
05-14-2020, 08:05 PM - 2 Likes   #178
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QuoteOriginally posted by bertwert Quote
Yeah. DFA 21mm Limited!
05-14-2020, 08:07 PM - 1 Like   #179
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QuoteOriginally posted by starjedi Quote
Yeah. DFA 21mm Limited!
Yeah - WR limited!

Updated 16-50 PLM

Good stuff...
05-14-2020, 08:14 PM - 1 Like   #180
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I was expecting the new DA* 16-50/2.8, but I'm surprised at the PLM.
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