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09-23-2008, 04:04 PM   #46
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normal vision?

QuoteOriginally posted by roentarre Quote
The 55mm lens perspective remains the same at this focal length and the imagery is closer to our normal vision.
The FOV of the DA*55 is 28.6°. It is not even remotely similar to how we see.

Our stereoscopic field of view is 100°; including peripheral vision it is 120°. Outside this we see with one eye or the other for a complete field of view up to 180°. The binocular field, within which both eyes observe an object simultaneously, has been defined as between 50 and 60°. That's a closer approximation to what looks "natural".

Many great photographers preferred the unmediated look of 28 or 35mm on full-frame. Check out the history of Leica for examples. These focal lengths produce a FOV of 76° and 53° respectively.

On digital 20-24mm seems the sweet spot. We need a DA* 24 f/2.

09-23-2008, 04:17 PM   #47
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QuoteOriginally posted by rparmar Quote
We need a DA* 24 f/2.
You can say that again !! Altough I'd prefer a simpler, "regular" DA 24/2 - i.e. an APS-C "equivalent" of the FA35/2 (come to think of it, "regular" DA primes seem to be nonexistent in the lineup). I think that's a much more glaring hole in the lineup than 15mm f/4 (which is already covered by the DA12-24, even if the latter is much bulkier).

But nobody said Pentax's decisions had to make complete sense. That's part of their charm, I suppose

Last edited by RBellavance; 09-23-2008 at 04:29 PM.
09-23-2008, 04:49 PM   #48
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QuoteOriginally posted by gnaztee Quote
Specs say 1.5 feet
Which probably means about 1 foot - for whatever reason, the minimum distance specs are almost always conservative.... ?
09-23-2008, 06:10 PM   #49
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QuoteOriginally posted by rparmar Quote
The FOV of the DA*55 is 28.6°. It is not even remotely similar to how we see.

Our stereoscopic field of view is 100°; including peripheral vision it is 120°. Outside this we see with one eye or the other for a complete field of view up to 180°. The binocular field, within which both eyes observe an object simultaneously, has been defined as between 50 and 60°. That's a closer approximation to what looks "natural".

Many great photographers preferred the unmediated look of 28 or 35mm on full-frame. Check out the history of Leica for examples. These focal lengths produce a FOV of 76° and 53° respectively.

On digital 20-24mm seems the sweet spot. We need a DA* 24 f/2.
Well. Strictly speaking, it would be 43 mm ltd close to normal visiual feel. Anything close to 50mm would be close enough to normal vision on my book. Any focal length between 40-60mm would be easy on the viewers' eyes.

Sure you would not want to hear my babble about human retina, 6 cell layers, optic nerve pathway and the perception of space, colour detection and intergration of visual circuit via occipital lobe.

09-23-2008, 06:12 PM   #50
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QuoteOriginally posted by FHPhotographer Quote
I'm with you on this one. And how is this better than my FA 50 f/1.4 that's still on the market new for less than $200?

This seems much the same as the DA 70 "replacing" the older FA 77 but generally being no great leap forward...but at least the newer lens was less expensive, but in this case $500 more is going to buy what, a few mm longer,weather sealing and a focusing motor that legacy Pentax bodies can't use?
FHPhotographer
Well Fa 50 f1.4 is the best prime in the world. But I think kit lens is more than enough.
09-24-2008, 06:06 PM   #51
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QuoteOriginally posted by RBellavance Quote
You can say that again !! Altough I'd prefer a simpler, "regular" DA 24/2 - i.e. an APS-C "equivalent" of the FA35/2 (come to think of it, "regular" DA primes seem to be nonexistent in the lineup). I think that's a much more glaring hole in the lineup than 15mm f/4 (which is already covered by the DA12-24, even if the latter is much bulkier).
Well, I'm not saying it is good or bad, but the lack of new DA primes without the * or ltd designation, I think that is on purpose. The way Pentax look at it, the zoom lenses are now good enough to replace ordinary primes, so they build a lens line consisting of ordinary zoom lenses + limited primes + * primes and * zoom's. Doesn't this makes sense? I don't mean from how you would like it to be, but if you look at what is coming out from Pentax. What may also play a part in this is that they know that the good backward compatibility means that a lot of us are putting old FA primes, old F primes, old A primes, old M and K primes and even takumars on the new digital cameras. So why make cheap ordinary primes for us? I'm not defending it, just trying to understand, to guess why the lens line look like it does.
09-24-2008, 06:29 PM   #52
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QuoteOriginally posted by Douglas_of_Sweden Quote
Well, I'm not saying it is good or bad, but the lack of new DA primes without the * or ltd designation, I think that is on purpose. The way Pentax look at it, the zoom lenses are now good enough to replace ordinary primes, so they build a lens line consisting of ordinary zoom lenses + limited primes + * primes and * zoom's. Doesn't this makes sense? I don't mean from how you would like it to be, but if you look at what is coming out from Pentax. What may also play a part in this is that they know that the good backward compatibility means that a lot of us are putting old FA primes, old F primes, old A primes, old M and K primes and even takumars on the new digital cameras. So why make cheap ordinary primes for us? I'm not defending it, just trying to understand, to guess why the lens line look like it does.
That makes a lot of sense, and that's how I understand things as well. I don't believe non-*, non-Ltd primes are coming back any time soon.

PS.: you can pry my FA35/2 and my F50/1.7 from my cold, dead hands
09-24-2008, 11:35 PM   #53
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Anybody knows if new lenses have RING USM or MICRO USM?

http://forum.ixbt.com/post.cgi?id=attach:20:25396:1609:1

here is from Canon
Ring USM, Micro USM and Micro USM II

09-25-2008, 12:41 AM   #54
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QuoteOriginally posted by jsherman999 Quote
Which probably means about 1 foot - for whatever reason, the minimum distance specs are almost always conservative.... ?
I think the specs are distance from object to either the sensor or the nodal point, not to the front of the lens. That might explain the conservative values if you didn't already take that into account.

Magnification of 1:6 seems decent to me. Should be a little better than the FA50 (1:8) and the 77L (1:7).
09-25-2008, 12:55 AM   #55
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QuoteOriginally posted by ogl Quote
Anybody knows if new lenses have RING USM or MICRO USM?

http://forum.ixbt.com/post.cgi?id=attach:20:25396:1609:1

here is from Canon
Ring USM, Micro USM and Micro USM II
60-250 is most probably the same micro motor as previous designs since this lens is Dual AF as previous DA* lenses.

The DA*55 (and DA17-70 btw), I dunno.
09-25-2008, 03:14 AM   #56
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QuoteOriginally posted by roentarre Quote
Well. Strictly speaking, it would be 43 mm ltd close to normal visiual feel..
That's on full frame but I was talking Pentax digital. The perfect normal is instead 28mm. But this need not correspond to any natural visual framing -- it's just a mathematically nice number based on the frame size.
09-25-2008, 07:39 AM   #57
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Anyone ever figure out what the "something special instore" is [or was intended to be] that was stated by Pentax late last year / early this year?

p.s. after recently reading about the ultra wide zoom Tamron that's only 250mm focused @ infinity, I wonder if this lens will have [be plagued by] that behavior?
09-25-2008, 07:45 AM   #58
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QuoteOriginally posted by thibs Quote
60-250 is most probably the same micro motor as previous designs since this lens is Dual AF as previous DA* lenses.

The DA*55 (and DA17-70 btw), I dunno.
60-250 is KAF2, like the other current DA*
55 is KAF3, like the 17-70 (which also explicitly has SDM on it). i don't think pentax has ring motors tho, it's the crappier micro motor
09-25-2008, 08:03 AM   #59
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QuoteOriginally posted by 24X36NOW Quote
I have no interest in APS-C lenses, but 60-250 is a lousy choice of focal lengths for the Pentax APS-C system. Since there are so damn few tele zooms (or high quality zooms in general for that matter) in their system to begin with, why duplicate everything from 60-135 that you already get with the 50-135 F2.8?? They should have gone with 135-405 F4, which would give you something that stacks seamlessly on top of the 50-135 F2.8, and would provide a nice FOV range similar to a 200-600 in 35mm, which would be an outstanding zoom range. It would also bring the zoom range down to 3:1, which would allow greater quality optics while still providing MUCH more reach. For those who complain about lens size/weight, who wants to carry around a suitcase full of long primes?! Even if you're willing to do that, you still don't cover all of the intermediate focal lengths.
I like the idea of a DA* quality 135-400 f4 lens ...however, lacking that the 60-250 and a prime 400 f4 would make a nice combo for when you need long glass. I don't think the 60-250 duplicates the 50-135 ...they really are intended for different usage and I like my 50-135 for medium telephoto work, and it's f2.8. I would buy the 60-250 where I need longer glass and replace my Sigma 100-300 f4.

Mike.
09-25-2008, 08:16 AM   #60
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QuoteOriginally posted by m8o Quote
Anyone ever figure out what the "something special instore" is [or was intended to be] that was stated by Pentax late last year / early this year?
I thought the "something special" was the complete redesign of the 60-250?? As opposed to just slapping a tripod collar on it...
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