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07-16-2008, 11:24 PM   #91
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QuoteOriginally posted by alexgn Quote
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.

Alex, you crack me up. New guy who can discount the collective wisdom of a forum because his interpretation of his 'web research' results point him in a direction contrary to said collective wisdom, and thus he declares his conclusion to said forum as the unassailable truth. And he marches forward.

Kinda reminds me of a guy with the initials..... RH.

Soldier on, Alex. (but order the 31ltd anyway and give it a try. Return to sender if it's offensive to your sensor.)



.

07-16-2008, 11:41 PM   #92
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QuoteOriginally posted by jsherman999 Quote
Alex, you crack me up. New guy who can discount the collective wisdom of a forum because his interpretation of his 'web research' results point him in a direction contrary to said collective wisdom, and thus he declares his conclusion to said forum as the unassailable truth. And he marches forward.

Kinda reminds me of a guy with the initials..... RH.

Soldier on, Alex. (but order the 31ltd anyway and give it a try. Return to sender if it's offensive to your sensor.)



.

The lens is great!!! It has to be used on film for optimal performance. That's all.

There's a lot of experience published on the Internet. I've just published the opinion of a seasoned photographer. Here's his biography.
Carl Weese Bio

I've published the results of an experienced tester who happened to like Pentax equipment too. The officials from Pentax would problem state something similar too.

Yet, someone from a forum thinks he knows more about the lens.

As for me buying the lens. If it was going to shoot film I'd buy it. For my DSLR - I won't.
07-16-2008, 11:52 PM   #93
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I'm willing to bet that the light loss from UV-IR-filter reflection will have the effect of turning the 31mm Limited from an f1.8 lens to about an f1.801 lens...

IE, as the say, the difference is the same size as the reproductive organ of an insect from the sub-order Nematocera of the order Diptera.
07-17-2008, 01:22 AM   #94
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The Online Photographer: The Pentax 31mm Ć’/1.8 Limited Lens


Alexgn

QuoteQuote:
"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."
I get a different feeling and perspective after reading the below regarding the legacies mentioned above by Carl.

What are your thoughts on the below comment

The Online Photographer: The Pentax 31mm Ć’/1.8 Limited Lens

The Pentax 31mm ƒ/1.8 Limited Lens

By Carl Weese



QuoteQuote:
So to conclude the first of several reports, let me go from that long-winded introduction to a short and sweet conclusion. In my use of the 31mm Limited—around 1,200 captures so far under a wide range of conditions —I can find no evidence of a “legacy problem.” In terms of resolution, including all the way to the edges of the frame, it is at least equal to results from the Pentax “pancake stack” of designed-for-digital compact DA Limited primes at 21, 40, and 70mm. Resolution is noticeably better than the designed-for-digital 12–24mm zoom, which is no slouch in its own right. I can’t detect any evidence of problems stemming from sensor flare. If the designers could do anything to make this lens more digital-ready, I don’t know what it would be.



Last edited by nulla; 07-17-2008 at 01:32 AM.
07-17-2008, 04:43 PM   #95
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Hello roentarre,
I realize that the size of the sensor or negative has nothing to do with the image IQ produced by any given lens lens, but the crop factor will effect any tendency to distort. The normal lens is the easiest to control and its focual lenght is determined by the size if the sensor/film. Here is a link to explain.

Normal lens - Wikipedia, the free encyclopedia

Dave

QUOTE=roentarre;293580]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.[/QUOTE]
07-17-2008, 04:49 PM   #96
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I'm wondering: is the halo around the girl in that picture an aspect of the lens itself or is it an effect of sharpening in Photoshop?
07-17-2008, 05:00 PM   #97
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QuoteOriginally posted by alexgn Quote
The lens is great!!! It has to be used on film for optimal performance. That's all.

There's a lot of experience published on the Internet. I've just published the opinion of a seasoned photographer. Here's his biography.
Carl Weese Bio

I've published the results of an experienced tester who happened to like Pentax equipment too. The officials from Pentax would problem state something similar too.

Yet, someone from a forum thinks he knows more about the lens.

As for me buying the lens. If it was going to shoot film I'd buy it. For my DSLR - I won't.

Your Mr. Weese says:
"I can find no evidence of a “legacy problem.” In terms of resolution, including all the way to the edges of the frame, it is at least equal to results from the Pentax “pancake stack” of designed-for-digital compact DA Limited primes at 21, 40, and 70mm. Resolution is noticeably better than the designed-for-digital 12–24mm zoom, which is no slouch in its own right. I can’t detect any evidence of problems stemming from sensor flare. If the designers could do anything to make this lens more digital-ready, I don’t know what it would be."

The person you are citing doesn't agree with what you are putting forward, and certainly isn't saying what you are saying he is saying.

I'd say you are an imbecile, but this forum appears to take a dim view of personal attacks.
I will say that you seem misguided, and that you have much to learn.
07-17-2008, 05:06 PM   #98
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QuoteOriginally posted by alexgn Quote
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.
Dude, you have no opinion. Unfortunately, you are a computer geek who likes to read the internet. You are not a photographer. You are a reader. You have no opinion. Use lenses... take pictures.... form an opinion of your own instead of taking on opinion of other real photographers. Do your own legwork. Use YOUR eyes. Photography even though digital now is still about artistry. If you have none..... just forget about it.

PS- As was stated, the author totally disagrees with your statement.... you must not be so good at reading then. Not good at reading. Give up on photography.. your eyes must not be so good.

07-17-2008, 05:50 PM   #99
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QuoteOriginally posted by Big Dave Quote
Hello roentarre,
I realize that the size of the sensor or negative has nothing to do with the image IQ produced by any given lens lens, but the crop factor will effect any tendency to distort.
.
Actually, the "crop factor" is more likely to improve a lenses performance. Using the example of the 31mm lens, it has an image circle large enough to cover the 35mm film format. As soon as we put it in front of an APS-C sensor, we are using closer to the center of the image circle, which is where any lens performs the best.
All else being equal, a lens with an image circle larger than is needed will outperform a lens with a barely adequate one.

The photozone tests clearly give the performance edge to the 31mm lens over the 40mm lens. That the 31 is also a stop faster is icing on the cake.

In another thread, I mentioned that in large format photography, my goto lens is the Nikkor 210mm f/5.6. This is a lens that will cover the 5x7 format. By using it on 4x5, I am not only in the sweet spot of it's performance, but I also have lots of good image circle to use for swings and tilts.
This is where alexgn has really gone off the rails with his assertion that the 31mm lens is best used on 35mm film.
By putting it on a DSLR, we are using the best part of a very good lenses image circle.

He has misread both the photozone test, which clearly puts the 31mm lens ahead of the 40mm lens, and he has misread the very person who he is citing as the person who he is using as a poster child for not using the 31mm lens on a DSLR.

This is not to say that the 40mm lens is not a very good lens. It is. However, I also have very reliable information that it is a rework of a 25 year old lens (the old M 40mm Pancake). If so, the 31 is a much more recent lens design, and has the advantage of computer design rather than a room full of people with abacus'.

We have a guy on the PDML like this. He comes up with a nonsensical theory, then doesn't bother to read any factual evidence that disputes his theory, including the very evidence he is using to support his theory that not only doesn't support his arguments, but actually disagrees with what he is citing it to say.

Last edited by Wheatfield; 07-17-2008 at 05:55 PM.
07-17-2008, 07:01 PM   #100
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Well stated Wheatfield

I applaud your post and those who have defended your views
07-17-2008, 07:23 PM   #101
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QuoteOriginally posted by alexgn Quote
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?
so only optical engineers can judge lenses? are YOU an optical engineer?
there's much more to lenses than the statistics on photozone that cannot be quantified
07-31-2008, 07:31 AM   #102
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Ltd 31mm?

Can anyone tell me very good reasons why not to buy that lens (and just save that money)? My try...is it FF-sensor suitable?
07-31-2008, 07:40 AM   #103
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QuoteOriginally posted by Harmonica Quote
Can anyone tell me very good reasons why not to buy that lens (and just save that money)? My try...is it FF-sensor suitable?
Sure is FF suitable, but ....
(1) it's so heavy you can't really walk around with it
(2) a lot of people want to have it, you should do different
07-31-2008, 08:55 AM   #104
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QuoteOriginally posted by Harmonica Quote
Can anyone tell me very good reasons why not to buy that lens (and just save that money)? My try...is it FF-sensor suitable?
I can't think of a single reason for not buying it if you can afford it.
For that matter, if you can't afford it, you should choose your child you like the least, sell it into slavery and use the funds to buy a 31mm lens.
In fact, if you have no children, you should have one, sell it into slavery, and use the funds to buy that lens.
07-31-2008, 09:30 AM   #105
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That was funny.

Noup...I just have some limited amount of money in my pocket right now.

Would Ltd 31mm be much better lens for potrait photography than my FA* 85mm?
Or would it be much better walk around lens than my FA* 28-70mm? At least it's most likely much, much sharper lens than that zoom even if using f7 - f10?
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