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09-29-2016, 07:10 PM   #31
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QuoteOriginally posted by builttospill Quote
This shouldn't be a surprise. In my experience, all FA*/FA Limited give better results than DA*/DA Limited lenses.
Given the fact that the FA 200 and the DA* 200 are supposed to be the same design I'm not sure that's truly a fair point.

09-29-2016, 07:13 PM   #32
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QuoteOriginally posted by normhead Quote
Having read different, I'm interested in your source.

Based on the renditions of images seen on the forum, I find the 77 and 31 both amazing lenses, though as a mainly wildlife/ landscape photographer who uses zooms in the wide end, I'd have little use for either. I own the 21 and have seen many DA 70 images. The DA 70, IMHO the only reason to take it over the 77 is price, and while the 21 is a great lens on APS-c, my take would be the 31 on FF is much better, and faster.

But then, my philosophy has always been cover your range w it 3.5-4.6 zooms and fill in with primes where you need speed. The 77, 31 and 43 are al 1.8 sub ƒ2 lenses. The DA limited, not so much. That being said, I put the 21 ltd on the camera whenever I can. It's the only limited I own, and I just reach for it whenever possible.
Follow the link I gave you and from there you have links to the patents.
As for the FA77ltd and A*85 you only need to compare the lens designs side by side to see that the 77ltd is just a slight mmodification of the A*85. It is true that Jun tweaked the A*85 into the FA77ltd, but to my knowledge it didn't result in a separate patent. At the same time Jun presented a 31/2.4 and the 43/1.9. Only the 43mm made it into production, as Pentax wanted all three FA ltds to be sub f2.

As for the DA ltds, I of course meant them used on an APS-C DSLR where the combined smaller size is a considerable advantage in some situations. Besides that, they are more modern design and suffer less need for post processing to get rid of optical abrevation etc. But I love them and own all the limiteds, except the 20-40 zoom.

Edit:

A*85/1.4


FA 77/1.8 limited


If you look carefully there are small changes on the 3rd to 6th elements, but it is clear he built it on the A*85. The drop in speed is logical as the A*85 is rather soft there. Why 77mm? Japanese number magics??

Last edited by Douglas_of_Sweden; 09-29-2016 at 07:25 PM.
09-29-2016, 07:19 PM   #33
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QuoteOriginally posted by Douglas_of_Sweden Quote

The 77/1.8 ltd was not a new design. It uses the same optical design as the A*85/1.4 by Ogawa Ryota. They just cut down the speed and gave it autofocus. The A*85 is anyway soft at f1.4.

Don't diss the DA limiteds. My two favorits among them are the 21ltd and 70ltd, both designed by Masakazu Saori...the same guy who designed the DFA* 70-210mm f2.8, currently the chief lens designer at Pentax.
I think you may be a little off in your assessment of the A* 85. I bought my FA 77 based on the same info you related - the tie in with the A* 85. However in my experience the A* 85 is not soft at all at f/1.4 - granted it is less sharp than at f/5.6 - but it is a razor sharp lens. The FA* 85 on the other hand is soft at f/1.4...

The FA 77 is a great lens - and I do like it more than I like the DA 70 - but the DA 70 is a sweet jem of a lens itself. They are just different enough that I still own both. Ironically these are two lenses that I own that were purchased new - very very few of the my other lenses were.

I no longer own the A* 85 to post pictures, my ability to manual focus it had declined. I bought the FA 77 as a way to rekindle that love.
09-30-2016, 02:47 AM   #34
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QuoteOriginally posted by builttospill Quote
This shouldn't be a surprise. In my experience, all FA*/FA Limited give better results than DA*/DA Limited lenses.
The DA *200 and the FA *200 are the same lens optically. The differences are cosmetic, weather sealing and SDM/screw drive.

09-30-2016, 05:01 AM   #35
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QuoteOriginally posted by Rondec Quote
The DA *200 and the FA *200 are the same lens optically. The differences are cosmetic, weather sealing and SDM/screw drive.
I assume some coating differences also. In all not much change.
09-30-2016, 05:36 AM   #36
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QuoteOriginally posted by Douglas_of_Sweden Quote
Follow the link I gave you and from there you have links to the patents.
As for the FA77ltd and A*85 you only need to compare the lens designs side by side to see that the 77ltd is just a slight mmodification of the A*85. It is true that Jun tweaked the A*85 into the FA77ltd, but to my knowledge it didn't result in a separate patent. At the same time Jun presented a 31/2.4 and the 43/1.9. Only the 43mm made it into production, as Pentax wanted all three FA ltds to be sub f2.

As for the DA ltds, I of course meant them used on an APS-C DSLR where the combined smaller size is a considerable advantage in some situations. Besides that, they are more modern design and suffer less need for post processing to get rid of optical abrevation etc. But I love them and own all the limiteds, except the 20-40 zoom.

Edit:

A*85/1.4


FA 77/1.8 limited


If you look carefully there are small changes on the 3rd to 6th elements, but it is clear he built it on the A*85. The drop in speed is logical as the A*85 is rather soft there. Why 77mm? Japanese number magics??
Funny how we can look at the same two less designs, you say one is copied from the other. But if the designs are accurate, only in the type and places of the elements. ON the other hand, saying all he did was tweak it...that would imply that to be truly his design he would have to redesign the wheel and do a completely new original design. SO I'd have to hear from a lens designer how original the 77 is. But then I'm looking at the actual curvature of the glass elements.

I would completely reject that it's not Hirakawa's design.

How can you say "he copied the deign but the changed a few things.?" The crux of the matter being , how much do you have to change something to make it your own? Given current copyright standards, very little. And yes, the 77 did have it's own patent. It was posted and linked to on the forum numerous times. And Jun Hirasawa's name was on the patent. There is no mention of any other designer.

A similar number of elements does not make a design similar. Or every 9 element lens would be a copy right infringement of the first 9 element lens.

Without examining every lens with the same number of elements, I personally would have no idea how original the design is. For all I know every lens with the same number of elements looks pretty similar. And it's surprising you don't know about the patent for the 77. I've quoted it many times, because of the phrase Jun HIrakawa used in the description. " A lens designed for the way people take pictures, not for the test charts. " is a rough paraphrase.

It's playing pretty loose with the facts to bas your whole opinion on a few lens diagrams.

Here's another link discussing the FA ltd.
https://www.dpreview.com/forums/post/53451224

Last edited by normhead; 09-30-2016 at 05:50 AM.
09-30-2016, 02:42 PM   #37
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QuoteOriginally posted by normhead Quote
Funny how we can look at the same two less designs, you say one is copied from the other. But if the designs are accurate, only in the type and places of the elements. ON the other hand, saying all he did was tweak it...that would imply that to be truly his design he would have to redesign the wheel and do a completely new original design. SO I'd have to hear from a lens designer how original the 77 is. But then I'm looking at the actual curvature of the glass elements.

I would completely reject that it's not Hirakawa's design.

How can you say "he copied the deign but the changed a few things.?" The crux of the matter being , how much do you have to change something to make it your own? Given current copyright standards, very little. And yes, the 77 did have it's own patent. It was posted and linked to on the forum numerous times. And Jun Hirasawa's name was on the patent. There is no mention of any other designer.

A similar number of elements does not make a design similar. Or every 9 element lens would be a copy right infringement of the first 9 element lens.

Without examining every lens with the same number of elements, I personally would have no idea how original the design is. For all I know every lens with the same number of elements looks pretty similar. And it's surprising you don't know about the patent for the 77. I've quoted it many times, because of the phrase Jun HIrakawa used in the description. " A lens designed for the way people take pictures, not for the test charts. " is a rough paraphrase.

It's playing pretty loose with the facts to bas your whole opinion on a few lens diagrams.

Here's another link discussing the FA ltd.
FA Limiteds ? Rest in peace: Pentax SLR Talk Forum: Digital Photography Review

There are finite numbers of designs and they can be grouped into several categories. People change the elements, add corrective optics etc, but many of the designs are related. If you look at 50 F1.4s from different manufacturers, they all look very similar, and they are indeed of the same 'design'. There is a series about that on lens rentals, that I think you might find very interesting. At least I did.

https://www.lensrentals.com/blog/2011/08/lens-geneology-part-1/
09-30-2016, 07:45 PM   #38
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I'm going with, the lens designer is th guy with his name on the patent. In music many songs share similar progressions and even refs, but that doesn't make them the same song. I never said the design wasn't based on a previous design. I said this one was designed by Jun Hirakawa. There simply is no debate. His name is on the patent, he expresses in the patent description a clear design philosophy that influenced his design. When you discuss influences in music, you don't claim that because Bob Dylan was influenced by Woody Guthrie, that Dylans songs were Woody's design. I'm not sure what's up with this effort to discredit a very well know Pentax designer, but the facts are clear. Muddy minds are confusing the issue, and of course claiming I'm the one that's mixed up.

Typical of Douglas_of Sweden, he claims I'm in error, and then provides... nothing but a couple of diagrams,are those representations even accurate?


Last edited by normhead; 10-01-2016 at 08:54 AM.
10-01-2016, 08:49 AM - 1 Like   #39
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QuoteOriginally posted by normhead Quote
There simply is no dissolute
What did we say about using "big" words when Driline is present? Not everybody gradimicated from College in 4 years. Some of us were on the 7 year plan.

QuoteOriginally posted by normhead Quote
I'm not sure what's up with this effort to discredit a very well know Pentax designer, but the facts are clear.
Everybody knows that Henry Ford designed Ferrari automobiles not Sergio Pininfarina, because as we know, it has 4 wheels and a motor
10-01-2016, 08:54 AM   #40
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QuoteOriginally posted by Driline Quote
What did we say about using "big" words when Driline is present? Not everybody gradimicated from College in 4 years. Some of us were on the 7 year plan.



Everybody knows that Henry Ford designed Ferrari automobiles not Sergio Pininfarina, because as we know, it has 4 wheels and a motor
Spell checker did that, I'm innocent. I can't help it if the darn computer can't guess what I'm trying to say.
10-02-2016, 08:05 AM   #41
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QuoteOriginally posted by normhead Quote
A similar number of elements does not make a design similar. Or every 9 element lens would be a copy right infringement of the first 9 element lens.
In fact most design depend on many earlier design like all patents. By design a patent grand you control for max 20 years but if you patent depend on other patent that are still under their 20 years you may have not be able to use it without approval, even if you improved the thing. But it is also a way of exchange: grant me unlimited right on your earlier patent and I'll give you unlimited right to the improvement...

Some company like IBM have a different philosophy. They patent all they can, like many but only as a matter of protection. They form a conglomerate with many other companies with the idea that everybody in the world can use their patent without restriction. Until the day you sue one of the company of the conglomerate. At that moment, all the companies look for their own patents and will do kind of massive attack to make your stop your claim on them.

When you make a patent you make it explicitely public so any expert in the field should be able to redo the same as yourself. The thing is for 20 years, you get to choose who can or can't if they can if they pay you money for it or no.

A part of the difficulty with all theses patents on all lenses that are all similar also include to ensure you own design is different enough than the next one so you don't get sued. Patenting every lens design variation kind of stupid as this doesn't look like profound innovation but just application of state of the art optics, but I guess you have kind of no choice.

Otherwise, I agree with you, if there the name of the guy of the patent, for all we can guess he his the guy that did the design. Who know if its his mother that said it to him... But that pure conjections and a bit silly. And when we look at the 2 drawings that are quite simplified view I am sure, we can already see that some lenses are different and not placed the same.

Last edited by Nicolas06; 10-02-2016 at 08:12 AM.
10-02-2016, 08:14 AM   #42
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QuoteOriginally posted by normhead Quote
Those FA limiteds all have a story. the 31 a joint design with Zeis I think, the 77 Jun Hirakawa's masterpiece. The DA ltd are nice, but as far as I know, there's nothing special about them in terms of design philosophy or anything else.
The DA ltd have 2-3 key properties that make them quite worthwhile:
- tiny
- great build quality
- very constrasty and extremely resistant to flare

There no many alternative lenses available and they fill an interresting niche.

I agree overall that the FA ltd are better but the price/size/weight are also different.
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