[normhead]

I'm still not finding the 36 MP of the K-1 is needed over the 24 MP of my K-3 or even the 16 MP of Tess' K-5. There are cameras of convenience, there are cameras more concernd with large prints and resolution. 99% of the market are convince cameras. Cameras like the 645s are fighting for market share in what is left over.

---

Last edited by normhead; 10-12-2018 at 07:14 AM.

[rdenney]

I was thinking of it from the POV of how the camera determines what the aperture it has is, and what the available range is if 2.8 is the largest native lens aperture that Pentax produces.

Hmmm. Beats me. But I’ll bet the software that does that sort of thing in the 645 line is the same code as used in smaller DSLRs, and those certainly do support fast lenses.

Rick “test for this evening: 105/2.4 67 lens on adapter” Denney

---------- Post added 10-12-18 at 10:56 AM ----------

I am not sure anybody ever asked for a 1.5kg semi-wide angle zoom that cost $4600, is f/4.5 and is only a DA design. As good as it is, its still a big-ass lens.



Considering they have the excellent DFA35mm, a newly designed 23 prime f/4 would be fine for landscape work.



For that same weight of 1.5kg, I would have preferred a useful sharp ultra-wide that was lighter and a second lens at 35mm.

The 28-45 demonstrates the point: large sensors, zoom, and extremely high levels of correction mean many elements, special glasses, sophisticated coatings, large size, and a hefty price tag.

And so does the statement that the 35 is excellent: one whose only experience is reading these pages will be torn between reports of excellence and complaints about field curvature, lateral color, purple fringing, lack of weather sealing, and slight softness wide open. Yes, even the DFA version. I bought my FA version from the stash of a Nat Geo photographer who had published a book on national parks. I gather he had replaced it with the 28-45 (I don’t know the guy, but we both know well the same dealer). He published books with it; whatever weakness I might find is probably more theoretical than real and I might be bringing that weakness with me.

Sidebar Mini-Rant To Larger Rant Not Directed At 2351HD: People want sharpness to the pixel at 100% on their screen, most of which (at 100 pixels/inch) show a piece of an image seven feet wide from a 645z. Any flaws they see at 100% get magnified everywhere except on prints that they actually make. The guys that really get paid to make microscopically sharp seven-foot prints need something bigger than 44x33, pixel count notwithstanding. They used to complain that 4x5 film was too small. These were the guys who traded their Rodenstock Sironar N lenses for Rodenstock Sironar S models, which are still relatively simple approximately symmetrical plasmats that were priced in the thousands (and not the one-thousands). (I was good for me—my Rodie N, bought used for a fraction of new, is simply superb.)

And it’s not about the number of pixels. My preference is for sensor resolution that exceeds lens performance so that the sensor isn’t the limitation of the system. Also, the flaws of lenses give them their unique character. (What gives the classic Sonnar beautiful faded-edge bokeh? Slightly under-corrected spherical aberration wide open.) I always used film with finer grain than the lens performance (when possible) for the same reason. Hence, many 8x10 large format photographers don’t print that big, but that large format stuffs a lot of subtlety into even a small print. Ansel Adams had lenses that were primitive by today’s standards, but even his big prints are sharp and richly detailed (they are also clear, but that isn’t about sharpness and detail). His small prints are no less compelling. It’s about tonality.

By the way, 28mm on 44x33 isn’t semi-wide. It’s wide all growed up—the equivalent of 21mm on small format by my math—half the format diagonal. Wider than that, even for architectural interiors, requires extreme skill. (In days of yore, 21 was always the specialty problem solver for architectural magazine photographers who used 35mm.) I get the appeal—I have a 14mm prime in my 24x36 kit, plus a 12-24 zoom. And I use a 47mm Super Angulon with 6x12 and a 65 with 4x5. But I’ve also made an idiot of myself with those lenses more often than not. They are spectacular in the finder but the prints often just look askew.


(47 on 6x12, one of few keepers)

The 645z is for people who make photographs, it seems to me. It’s not only successful as a digital medium, but also as a camera, even with the legacy lenses. Let’s make more prints and enjoy the benefits of those rich images.

Rick “sorry for the ramble” Denney

[2351HD]

I find I tend to tap out at around 18mm on FF, anything wider than that and the images tend to get a bit boring.

An ideal landscape kit for me is 18mm, 24-28mm, 40-50mm, 80-90mm and then a zoom such as a 100-400.

With a high res 50mp camera I can crop for anything in between when using the primes and get fantastic results.

Rick, one thing about lenses and sharpness. I am a hobbyist shooter and part of the fun for me is achieving technically excellent images with outstanding sharpness and contrast, it’s about getting the technical part right in the field. I get great joy from it even if the image comes out average from an artistic standpoint. So good quality lenses are important to the enjoyment of my hobby and many others.

They should also be considered important from a manufacturer standpoint.

[Digitalis]

ow that Fuji has announced that they are going to release a new 100MP sensor based mirrorless camera, where does that leave Pentax on the playing field?

Basically in the same bucket as Leica - not that there is anything wrong with that. Pentax and Fuji have very different goals in the photographic industry and in general have a different business Ethos, it's like comparing Apples to Anvils.

[donesteban]

There are two 100 MP sensors. One is 33x44mm, one is 41x54mm.

If talking about the small one, like Fuji is using it in the GFX 100 MP, well, that's right, pixels are 1.4 times smaller than at 50 MP. So pcitures might get softer If we llok at them at 100% and diffraction will start one stop faster, so stopping down further to solve the problem is no option. On the other hand, lenses that work well using the 1.4x TC on 50 MP, will do a good job on the 100 MP without TC for sure. Even the best 1.4x TC will just enlarge all softness by 1.4x, and real world TCs will add some further softness, too.

Then, there is this larger, sensor, too. Only the 28-45mm will not work on that one, as it is a real "crop" lens. So if going thes direction a new super wide lens will be rquired, too. But: The pixel pitch of the 645Z is about 80 MP in that sensor size. So pixels will not become much smaller to reach the 100 MP. I don't think the inner 33x44mm of thet sensor will show a noticalbel difference in sharpness at 100%, if we go to 100 MP using the big sensor. Maybe minor difference, but not much. Pixels will only get 1.13x smaller, not 1.4x. The trade off *might* be outside this 33x44mm area on the borders. The bigger sensor is as wide as the diagonal of the smaller one. So the borders at the middle of the picture hight of the bigger sensor will have the picture quality of the corners of the smaller sensor. Hard to predict what this means to the corners of the larger sensor. Wll, I'd guess, the good 67 lenses would have any problem with that, as it is still a crop sensor from their point of view. But it might be different for some 645 lneses in the way, that some can have blur in the corners, even when stopped down.

[fotophil]

There are two 100 MP sensors. One is 33x44mm, one is 41x54mm.

If talking about the small one, like Fuji is using it in the GFX 100 MP, well, that's right, pixels are 1.4 times smaller than at 50 MP. So pcitures might get softer If we llok at them at 100% and diffraction will start one stop faster, so stopping down further to solve the problem is no option. On the other hand, lenses that work well using the 1.4x TC on 50 MP, will do a good job on the 100 MP without TC for sure. Even the best 1.4x TC will just enlarge all softness by 1.4x, and real world TCs will add some further softness, too.

Then, there is this larger, sensor, too. Only the 28-45mm will not work on that one, as it is a real "crop" lens. So if going thes direction a new super wide lens will be rquired, too. But: The pixel pitch of the 645Z is about 80 MP in that sensor size. So pixels will not become much smaller to reach the 100 MP. I don't think the inner 33x44mm of thet sensor will show a noticalbel difference in sharpness at 100%, if we go to 100 MP using the big sensor. Maybe minor difference, but not much. Pixels will only get 1.13x smaller, not 1.4x. The trade off *might* be outside this 33x44mm area on the borders. The bigger sensor is as wide as the diagonal of the smaller one. So the borders at the middle of the picture hight of the bigger sensor will have the picture quality of the corners of the smaller sensor. Hard to predict what this means to the corners of the larger sensor. Wll, I'd guess, the good 67 lenses would have any problem with that, as it is still a crop sensor from their point of view. But it might be different for some 645 lneses in the way, that some can have blur in the corners, even when stopped down.

It is my understanding that the use of the larger 100 MP is restricted by contract (and probably cost) to the high end Hasselblad and Phase One Systems. The smaller 100 MO Chip is to be used by Fuji GFX and the Hasselblad X1D Systems. I would assume that the smaller chip would be a candidate for the P645Z upgrade. Although there has been no formal announcement of an upgrade, I believe the price of the P645Z was recently dropped - meaning what? My hope is that Pentax continues to develop their medium format digital system.

[donesteban]

At the time Pentax was reported to have signed a contract with Sony to be allowed to use the 100 MP sensor, there was the large one only.
I think, this sensor would still be available to Pentax, although it will be quite expensive.

The problem is most likely, Pentax is not willing to spend that much money, as it requires to develop a new body with the new sensor. They have even not been willing to develop a super wide angle lens for many yeras now. The 645 digital system is optimized for landscape photography. While this doesn't mean you have to offer a lens with 10 oder 12mm equivalent on a full frame DSLR, as this is really special, even in landscape photography, it means fpr sure you have to offer something in the 16 to 18mm FF equivalent. The old 25mm was about 19mm FF equivalent, so at least somehow close to this range. The 28-45 isn't, imagine Nikon or Canon not offering any lens wider than 22mm for their FF DSLR systems.Off course, Pentax didn't notice immediately there was a problem after discontinuing the 25mm. The 645Z was selling quite well. But this was mainly upgrade from the 645D, as the new sensor really has some big advantages. In my opinion, the number of customers, buying a 645Z body without owning a 645D body before, was getting quite small without the possibility to buy a 25mm, too.

And now, some years later, there is still no DA 21mm oder 23mm filling that gap. This company is not willing to develop such an important lens. With the bigger sensor, the 28-45 would not be compatibly anymore. So going in direction of bigger sensor is just nonsense, if Pentax is not able to develop a new super wide lens at the same time, too. Even worse, they would need a 21mm for the old 33x44mm system and something between 25 and 28mm for the full size 645 system. Well,a 24mm fitting both might be a compromise, OK.

[Digitalis]

And now, some years later, there is still no DA 21mm oder 23mm filling that gap. This company is not willing to develop such an important lens.

On a sensor like the 54x41mm IMX211 FI a DA 21mm lens works out to be roughly a 12mm superwide. I can only speak for myself, but for me such a lens would be a very low volume, specialty lens*. An optically improved D-FA25mm f/4 would be most welcome, and far more practical.


*even more so if it didn't have shift/tilt capability, though that would raise the cost and make it even more specialized.

[SylvainB]

On a sensor like the 54x41mm IMX211 FI a DA 21mm lens works out to be roughly a 12mm superwide. I can only speak for myself, but for me such a lens would be a very low volume, specialty lens*. An optically improved D-FA25mm f/4 would be most welcome, and far more practical.


*even more so if it didn't have shift/tilt capability, though that would raise the cost and make it even more specialized.

I agree that an update of the 25mm D-FA would do on the biggest sensor.
Hasselblad has a 24mm HCD lens (so not officially compatible with big sensor, but it actually is), and Phase One has nothing wider than 28mm. That would be nice to be able to compete if Pentax moves to the IMX211.
On the XCD with 33x44mm sensor, Hasselblad has a 21mm which seems really nice. And Pentax has nothing wider than 28mm at the catalogue (excluding the 25mm not produced anymore)

[donesteban]

On a sensor like the 54x41mm IMX211 FI a DA 21mm lens works out to be roughly a 12mm superwide. I can only speak for myself, but for me such a lens would be a very low volume, specialty lens*. An optically improved D-FA25mm f/4 would be most welcome, and far more practical.


*even more so if it didn't have shift/tilt capability, though that would raise the cost and make it even more specialized.

Well, whtat I wanted to say is this: They have not been able to provide a 21 to 23mm for the small sensor yet. If they would switch to the big sensor, they would have to provide a lens of about 28mm for this big sensor, as the 28-45 will not work on full 645 (I tried it myself on a film body, it is even not working unofficially). So they would have to build two new wide lenses when switching to the new sensor (about 22mm for 44x33 and about 28mm for the bigger sensor), or maybe merge the two it to one 24 or 24mm lens covering both systems (a bit wide for the big sensor and a bit longish for the small sensor, but still somehow OK).

The digital system is suffering form bad decisions in the past years. The 90mm macro is a very good lens, but for macro usage, the old 120/4 is as good and provides 1:1, not just 1:2. Why did they spend this high effort in bringing another "macro" lens? If I just imagine they would have developed a 120/2.0 LS instead for portrait and studio work with flash sync up to 1/500 or better...
And then the 28-45. Yes, a great lens, too, and matching very well to the rest of the system like the 45-85 or the 55/2.8. But a bad choice, if you are not able to provide the real super wide, too. If they knew from the beginning, they can only build one lens shorter than the 35mm, something between 21 and 24mm would have been the way to go.

Well, Fuji is now building these lenses. The 23mm is available there, a 110/2.0 as well. I think their managers are photographers, too.

In this situation, I don't think they will bring a 100 MP solution. Either big sensor with pixels only a little bit smaller, or some sensor seize, but much smaller pixels, both of them will need new lenses. The large sensor on the super wide side, the small 100 MP sensor will need high resolution replacments for some existing lenses, for example the 80-160 or the 150/2.8