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03-06-2013, 05:21 AM   #181
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QuoteOriginally posted by gazonk Quote
Besides, maybe retrofocus lenses are actually a good match for digital? For instance, I read the photozone.de test of the Fuji 35/1.4, and I must say I'm puzzled by the difference between center and edge sharpness, even at f/4. The Pentax DA35/2.4 is much more consistent across the frame.
QuoteOriginally posted by Anvh Quote
That's the problem with short register and digital sensor, the light needs to fall on the sensor as straight as possible, so with a short register the angle in the corners is getting to steep.
Indeed, the light needs to fall on the sensor as straight as possible, whatever the register distance.

This is the reason why the new Carl Zeiss flagship, Distagon T* 55mm f/1.4, has a retrofocus optical formula (Distagon) and not a double Gauss / symmetrical formula (Planar) like its predecessors the Planars 50mm f/1.4, and is said to enjoy unprecedented contrast and sharpness from edge to edge even at full aperture.


Last edited by Mistral75; 03-06-2013 at 05:31 AM.
03-06-2013, 05:26 AM   #182
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Indeed, Sony is very much pushing it. Far too much if you ask me with their very large sensor in very very small register.
A register distance the length of the normal focal length should be mostly ideal if you ask me. So 43mm for 135 format lenses and about 28~30mm for APS-C should work very well and should leave enough room for the mirror as well.
Also like has been said you can use normal simpler design for normal lenses and for wider lenses making them cheaper and better.

I really wouldn't mind if Pentax would go for APS-C special mount if they provide good adapter to K-mount with good (perfect) support.
It would also mean that the reason for getting FF is getting lower since you can get equivalent lenses for APS-C this way in terms of DOF.
03-06-2013, 05:29 AM   #183
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Very intersting, havent followed Zeiss that much recently.

Ricoh use a special micro lenses on their M-mount adpater/sensor no idea how good the corner sharpness is.
03-06-2013, 08:22 AM   #184
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QuoteOriginally posted by gazonk Quote
Exactly. Olympus was right with the telecentricity of 4/3 after all :-) So maybe APS-C with full SLR register distance and retrofocus normal-to-wide lenses still has some virtues...
Hah!

Bigger sensors = bigger cameras or distortion and microlenses on the sensor and all sorts of deviations implied. Leica's mediocre sensors still required new lenses, much to the benefit of the Leica bottom line at the expense of anything unique about Leica images, IMO. Then Fuji shortens the distance even more as does NEX and Canon EF-M, yada, yada. Note these can all handle a ~10mm M-mount adapter. so the main virtue of RF lenses is their wideness at speed, and you can get there, as Fuji's emphasis on all wides for the X-series makes a case for.

They get to do this because of better sensors with high-ISO capabilities and in-camera software ironing out the aberrations. Same with m43. So if you want compact, wide, and fast lenses on APS-C to FF, you need to shorten the registration, have a sensor with microlenses, and use software to correct aberrations.

Or you can buy a small APS-C DSLR like the K-x and the DA 15mm. I see that as a viable market approach.

03-06-2013, 10:40 AM   #185
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QuoteOriginally posted by Aristophanes Quote
Or you can buy a small APS-C DSLR like the K-x and the DA 15mm. I see that as a viable market approach.
The problem is that the DA 15mm isnt all that wide nor fast.
03-06-2013, 10:56 AM   #186
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QuoteOriginally posted by cali92rs Quote
The problem is that the DA 15mm isnt all that wide nor fast.
Its not really fast, but come on, its pretty wide. 15mm is very wide and even if you calculate an equivalence of 24mm, its still wide.
But this is part of the price you pay for getting a really tiny lens that produces good IQ.
03-06-2013, 10:59 AM   #187
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I'm a defender of the K-01 -- I have one and I like it. (The insane fire-sale pricing didn't hurt!)

But ultimately, it's clear to me that a very short register distance, like in the NEX series, enables the best of both worlds.

If you want compact lenses, at the expense of perhaps some corner softness and falloff, then you can have that. But if you want top-notch optical performance, then lenses can be designed to insert that extra space in front of the sensor, which will generally make them larger. Or you can use an SLR lens with an adapter.

I think the Canon EOS-M has the right idea here.
03-06-2013, 11:47 AM   #188
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QuoteOriginally posted by cali92rs Quote
The problem is that the DA 15mm isn't all that wide nor fast.
It's wide enough for the vast majority of WA shots. And it does so as a WA pancake.

High ISO sensors reduce the need for fast glass, especially wide where a super shallow DOF-enabled design defeats a lot of the purpose, especially AF, flare, CA, and distortion. even the vignetting with the DA 15 is readily controlled by software as it is mostly just light falloff.

If you want a wide lens with superb IQ, especially flare control (uber necessary in WA), the DA 15mm is a superior design. It pairs with high ISO sensors like milk and honey.

Sure, buy the Zeiss Distagon 1.4. It's frakking huge! It would look large on a 645D. For a Pentax lens roadmap this would be substantial overkill given the cost and teeny market appeal.

03-06-2013, 12:40 PM   #189
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Just to compare lenses from Fuji and Pentax (B&H):

Fuji:
18mm = 27mm @135 eq.
52mm filter
116 g
f/2
$599

14mm = 21mm
58mm filter
234 g
f/2.8
$899

Both of these require an APS-C body starting at either $999 (XE-1) to $1399.

Pentax:
15mm = 24mm
49mm filter
212 g
f/4
$649

The cheapest all-new Pentax APS-C body is the $649 K-30.

The Fuji 18mm has only 19 reviews despite being out awhile, whereas the Pentax 15mm has 95 reviews. And if using a benchmark for relative sales volume, the Pentax K-5 has 221 reviews while the X-Pro 1 from Fuji only 195.

I see similar stats from Flickr images, leading me to believe that Fuji's hybrid or RF-style offerings are outsold by the Pentax DSLR systems. I suspect price has a lot to do with it. Personally I prefer the Sony sensors in the Pentax series.

Fuji X-Pro 1 size compared to Pentax K-5:

Compare camera dimensions side by side

And the XE-1 to the K-30

Compare camera dimensions side by side
03-06-2013, 12:40 PM   #190
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QuoteOriginally posted by Aristophanes Quote
It's wide enough for the vast majority of WA shots. And it does so as a WA pancake.

High ISO sensors reduce the need for fast glass, especially wide where a super shallow DOF-enabled design defeats a lot of the purpose, especially AF, flare, CA, and distortion. even the vignetting with the DA 15 is readily controlled by software as it is mostly just light falloff.

If you want a wide lens with superb IQ, especially flare control (uber necessary in WA), the DA 15mm is a superior design. It pairs with high ISO sensors like milk and honey.

Sure, buy the Zeiss Distagon 1.4. It's frakking huge! It would look large on a 645D. For a Pentax lens roadmap this would be substantial overkill given the cost and teeny market appeal.
I think you are understating the market with the statement "vast majority" If there were no market for lenses wider than 24mm (or 15mm on APS-C), sigma would not have a zoom that starts at 8mm and another that starts at 10mm. Tamron has the same (10-24mm). Even Pentax has (had?) a 12-24mm zoom. Nikon and Canon both have 14mm (8mm APS-C equivalent) primes and no one is saying that it was a mistake that they introduced those lenses. Pentax has about 200 primes in the 30-55 range but none wider than 15mm??
03-06-2013, 12:46 PM   #191
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.... must be the wrong thread ... I was hoping to see signs of an upcoming SDM TC in the lens line up.

JP
03-06-2013, 04:24 PM   #192
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There is a TC on the raodmap right?
03-06-2013, 05:21 PM   #193
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QuoteOriginally posted by cali92rs Quote
I think you are understating the market with the statement "vast majority" If there were no market for lenses wider than 24mm (or 15mm on APS-C), sigma would not have a zoom that starts at 8mm and another that starts at 10mm. Tamron has the same (10-24mm). Even Pentax has (had?) a 12-24mm zoom. Nikon and Canon both have 14mm (8mm APS-C equivalent) primes and no one is saying that it was a mistake that they introduced those lenses. Pentax has about 200 primes in the 30-55 range but none wider than 15mm??
Pentax had a 14/2.8. At B&H it has 8 reviews. The Samyang 8mm for Pentax has 1 review.

The Sigma 10-20mm has 35 reviews in K-mount. 11 for the 8-16mm.

I'd say given the very weak demand Pentax wisely lets Sigma do the lifting and focuses instead on an excellent set of pancake/small primes.

Pentax also has the 10-16mm fisheye. And the 12-24mm (24 reviews and on back order), so the market is covered.

And ultra-wide was not even very popular in film; for that you went to MF or LF.

While not empirical measures, things like the B&H comments are indicative of demand curves.

Wide and fast = big and expensive and very, very niche. The comments here were for the lens roadmap to have a fast, wide prime. The reasons for this diminish when you look at the cost and functionality. If you really, really want one and can handle the cost and the weight, there are options. Let's not try and normalize this type of lens as a broadly supported market "want".
03-07-2013, 07:05 AM   #194
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Agree . . .

QuoteOriginally posted by jpzk Quote
.... must be the wrong thread ... I was hoping to see signs of an upcoming SDM TC in the lens line up.

JP
+1.

Jerry
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03-25-2013, 07:17 PM   #195
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I can't see the point of a ~20-40mm Limited zoom if it's not FF-compatible, the gap between DA21 and DA35 could be filled better with a 27/2.8.
Howether, looking at the size of the old FAJ 18-35/3-5-4.5 and FA 20-35/4, a (D)FA 20-35/4 Limited with about the size of the 31/1.8 could be quite usefull.

Last edited by Boris_Akunin; 04-08-2013 at 08:16 AM.
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