[MJKoski]

Display tech has perfect illumination and the needed dynamic range. Print does not. Good thing is, this lens release is exactly what I have wanted since first K-1. Modern Pentax WA lens for Pentax body. I hope it is better than 31mm ltd because...

Currently I print 1.25m or 1.5m wide depending on the space available (2m also but more rare) and questions have already started flowing in years ago about using a wall panel for showing a selection of large resolution photos. 8K is absolutely perfect for that. So there is no reason not to pay some attention to optical performance. It is OK to have sharp results @ f/5.6 but no more stopping than that. Sony A7R4 is already diffraction limited @ f/4 and 61MP is possible candidate for Sony sensor customers including Pentax. Future is for ultra sharp lenses. Shoot with max details today and you will be ready tomorrow.

What is the alternative for super high IQ and QC? Cellphones or other small mobile devices which have already reached APS-C IQ thanks to frame averaging. So, 21mm ltd must meet 2020 requirements for a digital system.

And BTW, 21mm Loxia is the level this 21mm Ltd should meet or exceed. The old 21mm Zeiss Distagon is the absolutely minimum level of performance. Otherwise, get your 21mm today by using Leitax mount.

[repaap]

Display tech has perfect illumination and the needed dynamic range. Print does not. Good thing is, this lens release is exactly what I have wanted since first K-1. Modern Pentax WA lens for Pentax body. I hope it is better than 31mm ltd because...

Currently I print 1.25m or 1.5m wide depending on the space available (2m also but more rare) and questions have already started flowing in years ago about using a wall panel for showing a selection of large resolution photos. 8K is absolutely perfect for that. So there is no reason not to pay some attention to optical performance. It is OK to have sharp results @ f/5.6 but no more stopping than that. Sony A7R4 is already diffraction limited @ f/4 and 61MP is possible candidate for Sony sensor customers including Pentax. Future is for ultra sharp lenses. Shoot with max details today and you will be ready tomorrow.

What is the alternative for super high IQ and QC? Cellphones or other small mobile devices which have already reached APS-C IQ thanks to frame averaging. So, 21mm ltd must meet 2020 requirements for a digital system.

And BTW, 21mm Loxia is the level this 21mm Ltd should meet or exceed. The old 21mm Zeiss Distagon is the absolutely minimum level of performance. Otherwise, get your 21mm today by using Leitax mount.

With little shaking my head on that screen thing I do kind a agree. But on Zeiss thing I agree completelly. I'm hoping something similat what distagon has, but 2020 standards, AF and WR just being some of that. One thing what has kept me from buying Zeiss 21(ofcourse €€€ too) is that it is completelly manual, not WR. I forgive my old FA limiteds, because they stil communicate with my K-1.


Now, this DFA 21 Limited is something what I have been waiting/hoping for many years. Especially for FF.

[ffking]

This is probably the most relevant comment in the whole thread.

It amazes me that the comments made by the lens designer in the video are about the closest you'll hear to any lens manufacturer even explaining, let alone defending, this difference of philosophy - they usually just sit and take the hits from (some, not all) reviewers. Any piece of design has to be judged against how successful it is in meeting its design criteria and how useful those criteria are, not just a one size fits all series of measurements, I think that manufacturers should give reviewers a bit more of a lead on this in their promotional material - it's not totally lacking but the signposts, which people who are essentially journalists need, are seldom there.

[house]

I think that manufacturers should give reviewers a bit more of a lead on this in their promotional material - it's not totally lacking but the signposts, which people who are essentially journalists need, are seldom there

It's incredible common for journalists to repeat press releases verbatim or at least re use key phrasing in their texts. They aren't given time (money) do to more than that.

You can clearly see how successful it is by reading sites like dpreview. They end up repeating key fragments of the sales pitch conciously or unconciously. Placing the right words in their heads is critical for getting the message across to the users.

[repaap]

It amazes me that the comments made by the lens designer in the video are about the closest you'll hear to any lens manufacturer even explaining, let alone defending, this difference of philosophy - they usually just sit and take the hits from (some, not all) reviewers. Any piece of design has to be judged against how successful it is in meeting its design criteria and how useful those criteria are, not just a one size fits all series of measurements, I think that manufacturers should give reviewers a bit more of a lead on this in their promotional material - it's not totally lacking but the signposts, which people who are essentially journalists need, are seldom there.

I’m also feeling little a bit spoiled by the fact that we get to have actually possibly to choose over what kind of photography are you in to most. Especially now when it has been actually explained by someone who design these things for us. And they are honest. (As honest as they can, of course)

[Digitalis]

21mm ltd must meet 2020 requirements for a digital system.

For extremely large prints that require critical sharpness throughout I have found that there is no substitute for a view camera. Once you get away from the constraint of a fixed focal plane the ability to extend DOF to cover the desired subject without stopping down beyond the diffraction limit is almost trivial. Pentax has never produced a tilt/shift lens before, however they can produce a camera body that has tilt shift functionality with existing lenses*. Such a camera would be a prime situation to exploit a mirrorless design approach which would put Pentax in a position of considerable advantage over their competition. Pentax could start with the wide angle lenses suited to landscape photography and develop longer lenses at a later point.

Of course all this is idealistic speculative conjecture: Under Ricohs wing Pentax will follow its own whims. But I do earnestly hope that some manufacturer has the audacity to produce such a camera, Pentax has produced a number of niche products over the years they are perhaps the only player that really can.



* Of course such a thing would require lenses with extended imaging circles, existing 35mm lenses could be used with tilt, however: shift would be constrained to the limits of the existing image cirlcle

[TwoUptons]

For extremely large prints that require critical sharpness throughout I have found that there is no substitute for a view camera. Once you get away from the constraint of a fixed focal plane the ability to extend DOF to cover the desired subject without stopping down beyond the diffraction limit is almost trivial. Pentax has never produced a tilt/shift lens before, however they can produce a camera body that has tilt shift functionality with existing lenses*. Such a camera would be a prime situation to exploit a mirrorless design approach which would put Pentax in a position of considerable advantage over their competition. Pentax could start with the wide angle lenses suited to landscape photography and develop longer lenses at a later point.

Of course all this is idealistic speculative conjecture: Under Ricohs wing Pentax will follow its own whims. But I do earnestly hope that some manufacturer has the audacity to produce such a camera, Pentax has produced a number of niche products over the years they are perhaps the only player that really can.



* Of course such a thing would require lenses with extended imaging circles, existing 35mm lenses could be used with tilt, however: shift would be constrained to the limits of the existing image cirlcle

Of course, Pentax already has a platform with lenses with an extended image circle... it just doesn't use the K mount...
Most of the 645 lenses cover a significantly larger image circle than the sensor size.

And frankly, that's a prime candidate for what you're describing... and a good way to get extra resolution at the same time...

-Eric

[ffking]

they can produce a camera body that has tilt shift functionality with existing lenses*

Pentax K-TS - any takers?

[Rondec]

It has gigantic vignetting, Coiseam, so it's not big enough to cover a FF sensor. 2.5eV or 2.8eV dropoff, depending on who's doing the measurement.

Barrel distortion with an ugly moustache contribution, according to one review, too, and they charge $1500!

There is no such thing as magic, lenses have to obey physics, sadly.

I think the tendency these days is to under-engineer lenses and then to have in camera or in software modules that fix them in post. Fortunately Pentax hasn't really gone down that road. But as you say, fixing a couple of stops of vignetting could easily make your corners pretty noisy.

I guess I am hopeful for some middle ground. Pretty corrected optics, small vignetting wide open that goes way stopped down to f5.6 and medium size. Good flare resistance is going to be key too.

I am afraid for MJKoski that have an in lens motor may make this not a great option. The winter temperatures surely spell trouble for this.

[clackers]

I think the tendency these days is to under-engineer lenses and then to have in camera or in software modules that fix them in post.

(Cough) Olympus. (Cough) Panasonic. (Cough) Fuji. (Cough) Sony.

[house]

I think the tendency these days is to under-engineer lenses and then to have in camera or in software modules that fix them in post. Fortunately Pentax hasn't really gone down that road.

You can't really rely on fixing distortion in software when you have an OVF the framing will become inaccurate. I'm quite confused about the supposed benefits of short flange for wide angles. When looking at the produced lenses sometimes the old dslr versions are better in others they've just made a trade off ditching distortion and vignetting in favour of resolution and contrast. But I think I've seen zeiss engineers claim that benefit as well as mirrlorless fans.

---------- Post added 05-19-20 at 03:18 AM ----------

Cough) Olympus. (Cough) Panasonic. (Cough) Fuji. (Cough) Sony.

The Leica Q2 is very extreme as well. You loose a huge part of the frame.

[BarneyL]

The old 21mm Zeiss Distagon is the absolutely minimum level of performance. Otherwise, get your 21mm today by using Leitax mount.

Just wanted to say that the old 21mm Zeiss Distagon is optically the same as the current Milvus 21mm. The latter has different WR housing and declickable aperture. Looks like Zeiss thinks, that the wide angle design from 2008 classic (or even older Contax 21mm, which it's derived from) is plenty ok for corner sharpness fetishists with absurdly high MPix cameras.

[Digitalis]

Most of the 645 lenses cover a significantly larger image circle than the sensor size.

That is a good idea, albeit the current list of wide angle lenses will have to be extended. 25mm on 35mm format won't satisfy the ultra-wide fetishists. The widest lens I have ever worked with on 8X10 format is to Goerz Hypergon 75mm which is a rather exotic and rare piece of glass, consider for a moment that 300mm is considered a "normal" on 8X10 format.

Pentax K-TS - any takers?

ME!

[bdery]

A wish that will not happen: an f/1.8 lens with non-rounded blades

F1.8 is not needed for me. Anything faster than F4 will work well. But straight aperture blades to create starbursts? Now that would be magical.

[Serkevan]

Goerz Hypergon 75mm which is a rather exotic and rare piece of glass

Does... does it have a metal flower covering the front element to act as the cap? I am utterly confused here O.o