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07-16-2008, 11:06 AM   #76
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I don't think the question is about being religious, but rather, realistic. What you suggest is that graphs can compare lenses. You also mention blind tests, and that is what I'm getting at.

Do you think you'd be able to tell between the FA77 and DA70 wide open? How about both at F/2.4? I doubt it. Thus, while graphs may suggest the DA70 is better, failure to distinguish photos between them would suggest it is not. The same applies to any reasonably similar comparison.

I don't think the FA Limiteds are better per se, I just do not think is is the other way around either. The performance differences are just too small to care about despite what graphs may suggest. Other aspects should dictate which to choose. DAs are cheaper and smaller and have quickshift, and are also available in shorter FLs. FAs are faster, more expensive, FF, and have aperture rings. I wouldn't use IQ as a factor.

In fact, I use DAs and FAs for those very reasons, and did not ever consider what people had to say about IQ.

07-16-2008, 11:20 AM   #77
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I guess it depends on what your priorities are. I choose a lens to get the best images on a given camera. But if you like velvet on the interior of the lens cap - that's fine too. I suppose.
07-16-2008, 11:28 AM   #78
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roentarre,
Is wide angle syndrome(distortion) a product of the focual lenght alone or the wider viewing angle, greater then 75 degrees? I beleive that it is a product of the wider viewing angle. This would make the 31mm, a fast normal lens with great depth of field on an APS-C sensor.

Dave

QuoteOriginally posted by roentarre Quote
31 ltd still has the wide angle distorsion perspective different from a 50mm lens.

Buying 31 ltd is all about the unqiue picture rendering that some of us appreciate.
07-16-2008, 11:37 AM   #79
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QuoteOriginally posted by alexgn Quote
... The new Limited editions designed and optimised for DSLR, performing better on DSLRs. And the tests show this. End of story.

Getting near 'close-minded' territory with that statement, aren't we, Alex?

Speaking as an engineer-type-person, if the level of MTF-type tests I see used everywhere were being relied on to say, build a bridge - I wouldn't be caught dead on that bridge. (But I'd stick around it to see if I could photograph it collapsing.)

The methodology being used can only measure some pretty basic stuff (LPmm, etc.) and despite looking 'scientific', are pretty limited. The publications and websites are doing their best, but they're also trying to sell themselves as an authority in a lot of cases. Let's just say that they're using methodology that is something short of rocket science.

It's useful information - very useful - but it's useful in helping you determine one particular measure of a lens, in an overall effort to choose one for a purpose.

Anyway, if you think you can get better images from a DA 40ltd than a FA 31ltd or FA 43ltd, go for it. You'll save yourself a bit of money at the very least.


.

07-16-2008, 11:53 AM   #80
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QuoteOriginally posted by jsherman999 Quote
Getting near 'close-minded' territory with that statement, aren't we, Alex?

Speaking as an engineer-type-person, if the level of MTF-type tests I see used everywhere were being relied on to say, build a bridge - I wouldn't be caught dead on that bridge. (But I'd stick around it to see if I could photograph it collapsing.)

The methodology being used can only measure some pretty basic stuff (LPmm, etc.) and despite looking 'scientific', are pretty limited. The publications and websites are doing their best, but they're also trying to sell themselves as an authority in a lot of cases. Let's just say that they're using methodology that is something short of rocket science.

It's useful information - very useful - but it's useful in helping you determine one particular measure of a lens, in an overall effort to choose one for a purpose.

Anyway, if you think you can get better images from a DA 40ltd than a FA 31ltd or FA 43ltd, go for it. You'll save yourself a bit of money at the very least.


.
If you publish your credible tests, since you have engineer expertise, on two lenses I will be very happy to read them. I think Pentax community will benefit from it too. I may even go and buy the lens if the tests show that the lens is better than the other on DSLR. At the moment, I can't see a good reason to use it on DSLR when there's a better option.

I still can't follow why some are upset about the fact the lens is not performing as well on DSLR as it does on film body. You may just use a quality CZ or Leica lenses designed on film via adaptor on a DSLR camera from another manufacturer and be surprised that the lens is not producing good images.
07-16-2008, 11:59 AM   #81
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If the 31mm LTD lens is Pentax's holly grail then I won't be posting any information I have found on this lens any more. It may not be correct at all and the lens is indeed the greatest lens Pentax has designed.
07-16-2008, 12:15 PM   #82
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QuoteOriginally posted by alexgn Quote
If the 31mm LTD lens is Pentax's holly grail then I won't be posting any information I have found on this lens any more. It may not be correct at all and the lens is indeed the greatest lens Pentax has designed.

No need to get upset. The tests aren't lying to you, they're just not able to measure every component of an image. It would take a much higher budget than the typical web site or even photo magazine has to develop a test that can, say, consistantly & accurately measure microcontrast deviations between lenses and manufacturers. LPmm-type stuff is the low-hanging fruit. Get a beer or two in one of the testers, and he/she'll admit that.

Here's my best suggestion, seriously - but both the 70ltd and 77ltd, or 40ltd and 31ltd - and compare them yourself on your new K200D. Then return the one that pleases you the least. (and don't let the 'tests' have their own placebo effect on you when you do that! )


.

Last edited by jsherman999; 07-16-2008 at 12:21 PM.
07-16-2008, 12:30 PM   #83
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I am not upset.

07-16-2008, 02:58 PM   #84
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QuoteOriginally posted by Big Dave Quote
roentarre,
Is wide angle syndrome(distortion) a product of the focual lenght alone or the wider viewing angle, greater then 75 degrees? I beleive that it is a product of the wider viewing angle. This would make the 31mm, a fast normal lens with great depth of field on an APS-C sensor.

Dave
Hi Dave

On APS-C sensor, the perspective does not change regardless of the crop factor. 31 mm has the perspective and feel just like a 31 mm through view finder on a FF camera just the sides of the image being cropped out.

I love 31 mm because I really like how it produces image with a particular feel and special impact at times. It is a specialty lens with unique metal construction and incredible contrast. Corner sharpness is important when the subject is off centre with a view to render some nice bokeh to compliment the theme. A good lens for a special purpose.

I love 50mm this focal length. It is easy on the eyes and it is so wonderful to use because it tests creativity of one's composition skill - the whole idea of photography. Even though it can be equivalent to 75mm on FF when it is used on APS-C sensor - I preferred the perspective from a normal 50mm.

31 mm is my favorite lens but least used. This should not deter anyone from having it. It is a lens that you could totally trust during travel or going on an assignment.

If we are talking photography just limiting to sharpness and distorsion alone from particular lens, this is surely off the trail. I do not appreciate certain ways of cutting a fish along certain muscle fascial planes until 15 years later. Sometimes I was a little horrified to see my gourmet experienced friends swallowing some sashimi that I thought the fish slice was poorly sliced and handled ... Sometimes it takes time to see the beauty in a lens and only a few appreciated that difference in lenses.



Yes, big deal. Hot chick will make good pics regardless how you shoot.
07-16-2008, 05:01 PM   #85
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QuoteOriginally posted by alexgn Quote
If you publish your credible tests, since you have engineer expertise, on two lenses I will be very happy to read them. I think Pentax community will benefit from it too. I may even go and buy the lens if the tests show that the lens is better than the other on DSLR. At the moment, I can't see a good reason to use it on DSLR when there's a better option.

I still can't follow why some are upset about the fact the lens is not performing as well on DSLR as it does on film body. You may just use a quality CZ or Leica lenses designed on film via adaptor on a DSLR camera from another manufacturer and be surprised that the lens is not producing good images.
I can't understand why I should allow myself to be pushed into believing tests that don't agree with my own experience. As an addendum, I had a look at the photozone reviews of the two lenses, and I'm not seeing where the 40mm is the better lens overall. The 31 has higher MTF, the 40 has slightly lower CA (a non issue as it is both a very slight difference, and is also something fully correctable in the RAW conversion), and the 40 has very slightly lower distortion, probably not by a visually noticeable amount, and this is correctable in post processing anyway. The 31 vignettes less at all apertures that the 40mm lens can compare to and they have more or less the same vignetting wide open, with the 31mm lens having a stop of speed advantage. You did realize that the 31mm lens is almost a full stop faster?
As in nearly twice as much light coming in wide open.
As in more depth of field control.
This is a big deal. It really does cost a lot more to make faster lenses, especially good ones.
The only downside to the 31 is its size, and it is a big, heavy lens, especially compared to the 40.

I don't consider the price to be a downside, I consider it to be the cost of admission.
If the 40 really was a much better lens than the 31, why does it not have the cult affection that the 31mm has?

Last edited by Wheatfield; 07-16-2008 at 05:47 PM.
07-16-2008, 09:04 PM   #86
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QuoteOriginally posted by alexgn Quote
You have to look at the context of the argument.

The new Limited editions designed and optimised for DSLR, performing better on DSLRs. And the tests show this. End of story.
As far as "performing better" even that is purely subjective to taste and the subject matter of what you're shooting. I read all the same tests and reviews and studied all the graphs and charts when I dumped my Canon and "L" lenses and bought into the Pentax system not so long ago. I thought a lot of the FA Ltd hype was wanting to agree or be agreed with, having the more expensive lens, and such. Being one of those analytical technical minded people that I happen to be, I decided to purchase the DA limiteds DA40, DA70 and DA35 when it too came out. I had figured that the newer DA's were optimized better for digital and had better sharpness across the frame and were more "homogenous" (I've seen that one poorly translated quote from 1 particular website repeated over and over..) etc...

So, I was thinking the DA's would yield a better digital image than the FA's would. I was positive of it

I was also thinking that some of my old M lenses I had for 25+ years would also be a nifty novelty and not yield images as good as the DA ltds either.

But that was my arrogance (I define arrogance as knowing something without trying for myself)

Later and recently I purchased the FA 43 and FA77 (just because) and I tried them out and compared real world usage of my favorite model, and my favorite scenes, and I diligently recorded the details of handling and usage and focusing and how the raw images processed and skin-tones and overall image and tone, how they printed on my printer, and lots of other things that I tested just for myself for no-one else, and I kept the lenses I liked the best and sold the ones that came in second. I wound up with a mixed bag, and very much different from what I thought it was going to be...

But my point is that all the charts and graphs and reviews can only possibly help you to narrow down which lenses to try out for yourself, not which lenses to proclaim as the best and buy them on that basis alone. For instance I liked the way the DA70 rendered scenics and a bunch of other things a lot better than the FA77. But my usage in that focal length was for portraits, which I preferred the FA77.

One of my overall favorite sharpest lenses that I tested was an M lens that I've had all these years, it beat out the DA and FA in sharpness, color, detail, highlight and shadow detail - you name it. And that obviously was not designed for digital at all.

So my favorite primes set so far consists of (all by my personal testing, for my tastes) 1 25 year old M, 2 FA limiteds, 1 DA limited and 1 Tamron.

I haven't made my mind up yet on the below 40mm prime, it might be the FA31, it might even be something else. I just picked up a "something else" that is a 30mm and man it is a beauty, real sharp, rich colors, I want a FA31 very badly, but I'm willing not to own one, that's ok, but I will now rent or borrow a FA31 before deciding which one I myself like the best...
07-16-2008, 09:14 PM   #87
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Another comment on the 31mm Lmt & K10D from Pentax blog.

Carl Weese on the FA Pentax 31mm Limited Lens:

"When SLR cameras were introduced, “retrofocus” wide angle lens designs had to be invented. This is a lens that is physically farther from the film than its effective focal length, necessary to get the lens out of the way of the SLR mirror. A similar manuever is needed to make normal and wide lenses for dSLRs deliver their light rays nearly perpendicular to the sensor (...) The second legacy lens problem (there are more than two but these are the ones we can actually see and deal with as consumers) has to do with the highly reflective glass that covers the digital sensor. It bounces a lot of light back to the rear element of the lens, far more than film. This means that a lens meant for digital capture needs just about as much attention to anti-reflective protection for light coming back from inside the camera as it does for the imaging light coming in from the scene being photographed."

Carl's final verdict validates the outstanding lens' ability to avoid all pitfalls and play well with his K10D, judging its resolution to be on par with the newer DA "pancake" Limited lenses. It's too bad that these original FA Limited lenses are a bit difficult to find without going to a major retailer like B&H Photo, but Pentax is still sending them out there into the world, in "pro" black or silver finish, and they are definitely a treat should you get a chance to use one.

OK1000 Pentax Blog: Carl Weese on the FA Pentax 31mm Limited Lens

Once again: use the lens on the camera for which the lens was designed.
07-16-2008, 09:17 PM   #88
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QuoteOriginally posted by augustmoon Quote
As far as "performing better" even that is purely subjective to taste and the subject matter of what you're shooting. I read all the same tests and reviews and studied all the graphs and charts when I dumped my Canon and "L" lenses and bought into the Pentax system not so long ago. I thought a lot of the FA Ltd hype was wanting to agree or be agreed with, having the more expensive lens, and such. Being one of those analytical technical minded people that I happen to be, I decided to purchase the DA limiteds DA40, DA70 and DA35 when it too came out. I had figured that the newer DA's were optimized better for digital and had better sharpness across the frame and were more "homogenous" (I've seen that one poorly translated quote from 1 particular website repeated over and over..) etc...

So, I was thinking the DA's would yield a better digital image than the FA's would. I was positive of it

I was also thinking that some of my old M lenses I had for 25+ years would also be a nifty novelty and not yield images as good as the DA ltds either.

But that was my arrogance (I define arrogance as knowing something without trying for myself)

Later and recently I purchased the FA 43 and FA77 (just because) and I tried them out and compared real world usage of my favorite model, and my favorite scenes, and I diligently recorded the details of handling and usage and focusing and how the raw images processed and skin-tones and overall image and tone, how they printed on my printer, and lots of other things that I tested just for myself for no-one else, and I kept the lenses I liked the best and sold the ones that came in second. I wound up with a mixed bag, and very much different from what I thought it was going to be...

But my point is that all the charts and graphs and reviews can only possibly help you to narrow down which lenses to try out for yourself, not which lenses to proclaim as the best and buy them on that basis alone. For instance I liked the way the DA70 rendered scenics and a bunch of other things a lot better than the FA77. But my usage in that focal length was for portraits, which I preferred the FA77.

One of my overall favorite sharpest lenses that I tested was an M lens that I've had all these years, it beat out the DA and FA in sharpness, color, detail, highlight and shadow detail - you name it. And that obviously was not designed for digital at all.

So my favorite primes set so far consists of (all by my personal testing, for my tastes) 1 25 year old M, 2 FA limiteds, 1 DA limited and 1 Tamron.

I haven't made my mind up yet on the below 40mm prime, it might be the FA31, it might even be something else. I just picked up a "something else" that is a 30mm and man it is a beauty, real sharp, rich colors, I want a FA31 very badly, but I'm willing not to own one, that's ok, but I will now rent or borrow a FA31 before deciding which one I myself like the best...

Precisely, who are you? An optical engineer or a guy who tested a couple of hundreds of lenses and many photographers actually trust your tests?
07-16-2008, 09:31 PM   #89
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I've read more on this lens after having a little argument here, since I am in process of searching for quality primes for my DSLR. As far as I am concerned - the 31mm Ltd is a great lens it's just have to be used on a film camera and not on DSLR for optimal performance.
07-16-2008, 10:49 PM   #90
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QuoteOriginally posted by Wheatfield Quote
I can't understand why I should allow myself to be pushed into believing tests that don't agree with my own experience. As an addendum, I had a look at the photozone reviews of the two lenses, and I'm not seeing where the 40mm is the better lens overall. The 31 has higher MTF, the 40 has slightly lower CA (a non issue as it is both a very slight difference, and is also something fully correctable in the RAW conversion), and the 40 has very slightly lower distortion, probably not by a visually noticeable amount, and this is correctable in post processing anyway. The 31 vignettes less at all apertures that the 40mm lens can compare to and they have more or less the same vignetting wide open, with the 31mm lens having a stop of speed advantage. You did realize that the 31mm lens is almost a full stop faster?
As in nearly twice as much light coming in wide open.
As in more depth of field control.
This is a big deal. It really does cost a lot more to make faster lenses, especially good ones.
The only downside to the 31 is its size, and it is a big, heavy lens, especially compared to the 40.

I don't consider the price to be a downside, I consider it to be the cost of admission.
If the 40 really was a much better lens than the 31, why does it not have the cult affection that the 31mm has?
If you really want to muddy the waters somewhat, throw the non-limited FA 35/2 into the mix. Sure the build is plastic, but the performance is not too far off that of the limiteds. After considering the price/benefit ratio, I put my money on the 35/2 and have been mucho pleased with the results. I now expect the fans of the new DA 35/2.8 Limited to jump into the fray!

Steve
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