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Forum: Pentax Medium Format 12-08-2020, 06:20 AM  
Post your medium format photos!
Posted By rdenney
Replies: 16,017
Views: 2,643,971
I was thinking exactly the same thing. Porter taught us that a messy forest scene without a single primary subject can provide a subject in its totality.

Rick “always recommended for color photographers” Denney
Forum: Pentax Medium Format 12-08-2020, 05:45 AM  
645z Preferred Portrait Lens
Posted By rdenney
Replies: 25
Views: 1,642
That one is cheap enough, perhaps, but it’s an older model. We called these “zebras”, and they are single-coated. The version after these had black barrels but still the angled rear section, and might be multicoated. The latest version had a stepped barrel instead of the angled section, multicoating, and a simpler an more reliable stop-down mechanism. End of production models were the same but with short serial numbers. I’ll find a pic of one (I have no access to the gallery from within Tapatalk) later on and post it.

Adaptors are available from DVDTechnik in the Ukraine. These are the same as Hartblei adapters you sometimes see.

http://www.dvdtechnik.com/?p=res&pn=1&p_t=view&id=60&mid=82&cur=usd

Rick “who has a zebra and the latest version, and think the multicoating is worth the search” Denney
Forum: Pentax Medium Format 12-07-2020, 08:32 PM  
Any other must have Russian medium format lenses?
Posted By rdenney
Replies: 4
Views: 885
Still catching up.

Yes to the CZJ MC-Sonnar 180/2.8. Not so excited about the 120 Biometar.

If you really need a shift lens, yes to the Arsat 55/4.5 PCS. Don’t expect to make gigantic prints for up-close viewing.

Yes to the Pentacon Six bellows. Mount a copy lens in a drilled P6 body cap.

The 80mm CZJ Biometar is a classic 5-element Planar (like the western Planar used by Hasselblad and Rollei in the day), but I’m not sure it’s better than either of the Pentax 75’s. It is a different look.

The 60mm Schneider Curtagon (for the Exakta 66 Mk. III, a Kreuznach lens from the 90’s) is a legendary unicorn. The brand is “Joseph Schneider” but it’s a Kreuznach lens from the time Mannesman owned them, as I recall. If you find one, decide you hate it and must discard it. I’ll provide the trash can. The Schneider 80/2.8 Xenotar is probably better than any other 75/80 in an easily adaptable mount. Also rare. Even more rare is the 55mm Super-Angulon shift lens. I’ve seen and handled the Xenotar and Curtagon, but I’ve never laid eyes on the SA. There was a myth that Joseph Schneider made a 40mm Curtagon, but nobody I know has ever seen one. These are not Russian lenses, but post-unification western lenses, and were priced accordingly.

Rick “adapters installed on the fisheye and the 180 Sonnar by default” Denney
Forum: Pentax Medium Format 12-07-2020, 08:09 PM  
645z Preferred Portrait Lens
Posted By rdenney
Replies: 25
Views: 1,642
Catching up from an extended break.

Carl Zeiss Jena MC-Sonnar 180mm f/2.8. A bit long, but creamy old-school rendering and the best bokeh on the planet. Truly a world-class portrait lens. It comes in a Pentacon Six mount, but adapters are cheap. Get the latest version with the stepped black barrel. Try to find the 10mm extension tube if you want to do tight headshots.

Unfortunately, I don’t have a world-class portrait, or even a crappy one, available for public viewing made using this lens on a 645z.

So you’ll have to take my word for it :)

Rick “worth the search” Denney
Forum: Pentax Medium Format 11-14-2020, 03:33 PM  
Grand Lens Test 10: The 645 A* 300mm f/4
Posted By rdenney
Replies: 29
Views: 2,995
Well, the 645 A* 300 is in a different category than the 200 FA.

Be careful of assertions without data. Those are the same kinds of assertions that kept you from trying the 33-55 for a time, as I recall.

Rick “whose 67 300 is not the M*, and so not offering assertions one way or the other” Denney
Forum: Pentax Medium Format 11-13-2020, 10:01 PM  
Grand Lens Test 10: The 645 A* 300mm f/4
Posted By rdenney
Replies: 29
Views: 2,995
Richard, do you have real test results to back that up? The 645 A* 300 (then lens discussed in this thread—not the FA) is justifiably famous as one of the best in the line.

Covering a larger image circle doesn’t make a lens sharper in the middle, by the way. In fact, in my experience it’s the reverse.

Rick “who knows what this lens can do” Denney
Forum: Pentax Medium Format 11-13-2020, 09:56 PM  
Grand Lens Test 10: The 645 A* 300mm f/4
Posted By rdenney
Replies: 29
Views: 2,995
The rings are quite solid—solid enough for time exposures assuming the tripod is—and the diameter is a perfect fit.

I’m not close to the lens to measure the diameter, but the rings shown fit the 645 A* 300/4 perfectly.

Rick “but you have to mess with it to solidly mount a tripod plate” Denney
Forum: Pentax Medium Format 11-03-2020, 10:12 AM  
Post your medium format photos!
Posted By rdenney
Replies: 16,017
Views: 2,643,971
Yes.

Oh, and yes again.

But it felt like assembly language then, too.

I started with FORTRAN, and because of that (in Nicklaus Wirth’s words) I was permanently and irreparable brain damaged. But every penny I ever made writing software, which was a good side hustle for me in the late 80’s and early 90’s, came from using Pascal (which Wirth, of course, developed). That started with Pascal on the University of Texas at Austin’s CDC Dual-Cyber mainframe, then it was Turbo Pascal (which I bought for $49 to run on my Kaypro II), then Pascal with Objects, where I explored event-driven programming.

It should have been an easy jump to C++, but it just took too long to write anything in C.

Still on my shelf:


Rick “the coolest language you never want to learn” Denney
Forum: Pentax Medium Format 10-04-2020, 05:38 AM  
Post your medium format photos!
Posted By rdenney
Replies: 16,017
Views: 2,643,971
No, Craters of the Moon National Monument in Idaho, on the high road between Idaho Falls and Boise.

It’s not much different than the more recent lava flows from Mount Taylor that created the Malpais. Mount Taylor is one of the four sacred mountains of the Navajo—a special place for them and for me. But the Yellowstone super volcano is an enormous hot spot under the crust that is very active, though it only erupts violently every 600,000 years or so. Craters of the Moon formed from one of its side channels, more recently that when the upper tectonic plate was over that hot spot. I could spend years in that area and not see it all. As it was, I had two days on that trip.

Rick “probably was the last time for traveling by air with serious film equipment” Denney
Forum: Pentax Medium Format 10-03-2020, 09:04 PM  
Post your medium format photos!
Posted By rdenney
Replies: 16,017
Views: 2,643,971
Catching up on my Yellowstone-area mini-project from 2015, pre-645z. On that trip (I just had a day--the last day the park was open before winter, and cold, snowy, and rainy, depending on elevation), I use the 67 some and my Canon 5D quite a bit (mostly because it could deal with the moisture). I won't show the latter, of course--this is a Pentax forum.

I showed an image from this series a couple of years ago, but these four are new. Film was Kodak Extar 100, scanned in a Nikon 9000ED using Vuescan. The skies were heavy and dark, and the shutter times long. But I have a robust tripod. I worked on them with Photoshop 5.5 back then, but now went back over them with the current version, and really do appreciate a better range of tools in the current version, particularly access to the Camera Raw filter from within Photoshop.


Early Snow at Craters of the Moon NM, 2015.




Snow on Fall Colors, Craters of the Moon NM, 2015.



Isa Lake Mostly Frozen, Yellowstone 2015.



Smoke Mountain, Yellowstone, 2015


Rick "who had to change his P67 battery with freezing fingers and snow blowing into the car at Craters of the Moon" Denney
Forum: Pentax Medium Format 09-18-2020, 08:33 PM  
Post your medium format photos!
Posted By rdenney
Replies: 16,017
Views: 2,643,971
I did that in 2000, 20 years ago to the day, but we picked up the camper van in Auckland and did the north island, too. We thought next time we’d fly into Christchurch and forget the ferry. That was going to be for our tenth anniversary, and we just passed 20.

I made lots of pictures, but all small format and all (of course) on film. I need to back and look through those.

I saw lots of tourists at Milford Sound, but we took the tour bus from Queenstown to avoid the crowds. A mistake.

Rick “honeymoon pics—not art” Denney
Forum: Pentax Medium Format 09-17-2020, 09:38 AM  
Digital 67
Posted By rdenney
Replies: 45
Views: 2,316
Medium format roll film in professional cameras was intended for enlargement from the beginning, certainly before the Leica.

And 4x5 and larger enlargers have been made since the days of dry plates.

Miniature cameras (as 35mm was originally called) were looking for extreme portability, but even more looking for a cheap bulk film source, which is why Leitz used 35mm cine film. It’s not that they made enlargement a thing, it’s that enlargement made 35mm practical—35mm makes no sense without enlargement or projection. That’s why Leitz sold enlargers as well as cameras.

Larger formats generally provide more tonality, resolution and detail for a given optical, film/sensor, and printing state of the art, but at higher cost and reduced convenience.

The main reason for smaller digital sensors is yield—for a given wafer, one flaw ruins half the wafer for medium format, but only one of many APS-C or smaller sensors made from that wafer. Error reductions and production reliability have reduced costs, but volumes with large sensors are very low which increases cost.

Personally, I’m hoping for an affordable 4x5 digital back that will attach to a camera using Graflok rails.

Rick “Ansel Adams was making amateur enlargements from a quarter-plate camera before the Leica was invented” Denney
Forum: Pentax Medium Format 09-08-2020, 04:44 AM  
Post your medium format photos!
Posted By rdenney
Replies: 16,017
Views: 2,643,971
Ed speaks for me, except more eloquently.

Rick “whose father is 92” Denney
Forum: Pentax Medium Format 09-04-2020, 03:56 PM  
Pentax-FA 645 80-160mm F4.5 lens discontinued
Posted By rdenney
Replies: 19
Views: 1,514
Yes. Small high-dollar products are routinely made this way—it reduces production costs by a greater amount than inventory costs (which are low because the product is small). Expensive wristwatches are the classic example.

Rick “recalling the production cards for Carl Zeiss Jena that assigned a serial number range for batches never larger than a few thousand before production” Denney
Forum: Pentax Medium Format 08-20-2020, 08:45 PM  
advice for 645z for astro and telescope
Posted By rdenney
Replies: 33
Views: 1,520
Telescopes have had for centuries clock drives that would track the sky. A computer is not necessary to do that. It seems to me that the computer made it possible to find difficult objects without really knowing how, and yo track the sky using a relatively inexpensive alt-azimuth mount.

Even my cheap Meade Newtonian telescope has an equatorial mount with a clock drive. But doing astrophotography with that stuff would require a very calm night and an ultralight camera. A setup that could handle a 645z would be beefy and expensive, with or without a computer.

Richard Berry once described astrophotography as the darkest corner of the dark jungle that is amateur astronomy. It takes real commitment.

That said, I’ve gotten the best results I ever imagined possible using the 645 FA 400, 40 exposures if 1-5 seconds, and Sequator. I was able to resolve (barely!) the spiral arms of M108 in a bad sky on my first attempt, and that’s not a trivial thing. The 400 is nearly half the focal length and nearly the same focal ratio as my Meade.



Rick “remembering finding stuff by hopping from star to star” Denney
Forum: Pentax Medium Format 08-20-2020, 08:10 PM  
Arsat 30 field of view on Pentax 645 digital?
Posted By rdenney
Replies: 7
Views: 654
Yes, but only slightly.

But the chances of me actually doing it are pretty low. Being able to do something isn’t the same thing as having a real reason to do it.

Rick “who would probably never expose a single sheet with it” Denney
Forum: Pentax Medium Format 08-20-2020, 01:47 PM  
Arsat 30 field of view on Pentax 645 digital?
Posted By rdenney
Replies: 7
Views: 654
Sorry for the late hit. The Arsat is intended to be a full-frame fisheye on the 6x6 format, providing a 180-degree field of view diagonally, corner to corner.

Typically, a fisheye has an image circle of 180-degree coverage that is a little less than three times its focal length. So, a 15mm fisheye’s image circle is a hair larger than the 24x36 frame, and an 8mm fisheye fits entirely within the 24mm narrow dimension.

Thus, a 30mm fisheye covers the 6x6 frame diagonal, and a 35mm fisheye covers the 6x7 frame diagonal. The 30mm fisheye would produce a circular image on the 4x5 large-format frame, and dint think I haven’t been tempted to try and make that work.

Here’s a 30mm Arsat photo on 6x6 film, displayed without cropping:



Rick “who misssd this thread earlier” Denney
Forum: Pentax Medium Format 08-20-2020, 01:11 PM  
645z Shutter inconsistent.... Why is that?
Posted By rdenney
Replies: 8
Views: 615
Slow memory card?

Rick “guessing—also didn’t see any attachments” Denney
Forum: Pentax Medium Format 08-19-2020, 07:43 PM  
Post your medium format photos!
Posted By rdenney
Replies: 16,017
Views: 2,643,971
It will certainly reduce contrast at all spatial resolutions, and that will undermine the appearance of detail. But most of what it removes is the surgical part of surgical sharpness.

It sounds like the Cokin has a similar design to the Softar. That’s good to know.

The Zeiss Jena 180/2.8 has a bit of under-corrected spherical aberration, which I think is why it renders such beautiful bokeh. Wide open, it degrades the contrast if fine detail enough that skin tones no longer appear choppy, and I have never really wanted more softness than that. But at that focal length and aperture, the image gets out of focus in a hurry as subject matter moves away from the focus plane, and that makes the stuff in focus appear sharper. It’s a great combination of effects for portraiture.

Rick “who likes spherical aberration as a softening agent only in slight amounts” Denney
Forum: Pentax Medium Format 08-18-2020, 08:23 PM  
Review: Pentax Medium Format Mirrorless, 1955 Edition... The Takane Mine Six IIF
Posted By rdenney
Replies: 7
Views: 3,016
Looks like a knockoff of an Agfa Super Isolette (the coupled rangefinder version). Most of the Japanese companies were also knocking off the Rolleiflex (or, more like, the Rolleicord), though only Yashica persisted into the Japanese excellence period starting in the 60’s. (Mamiya did it one better with an interchangeable-lens design).

Is the lens a triplet, or a four-element Tessar type?

I thought about picking up a Super Isolette once upon a time, then perhaps the Soviet knockoff of it, the Iskra. The Iskra used a very decent Tessar-type Industar lens. But a unique buying opportunity never appeared when I was interested.

Rick “not thick on the ground” Denney
Forum: Pentax Medium Format 08-16-2020, 09:04 PM  
Post your medium format photos!
Posted By rdenney
Replies: 16,017
Views: 2,643,971
Most soft-focus lenses allow to dial in spherical aberration.

Not my favorite approach. I like the kind of soft focus that adds a subtle halo around sharp details. The best purely optical solution I’ve seen was the Zeiss Softar, which is a flat filter with bumps glued to it. The space between the bumps renders a sharp image, and the bumps add the soft effect. I can also do it in Photoshop with a duplicate layer filtered with a Gaussian blur, with the transparency turned up to allow the sharp image to come through.

I had a Canon soft-focus lens that used spherical aberration. It fell apart, but I didn’t miss it and never had it repaired.

But I also have to admit that intentional soft focus is an effect I find too conspicuous most of the time.

Rick “the Cokin approach might be okay” Denney
Forum: Pentax Medium Format 08-16-2020, 03:10 PM  
medium format and dimensionality
Posted By rdenney
Replies: 46
Views: 3,448
Perhaps you are missing my point. It’s not just more pixels, it’s more large pixels.

And if you haven’t heard about better tonality in full-frame vs APS-C, then I have to think your aren’t reading the same things I’m reading. Because I’ve sure heard about it, and have for years. But then my first full-frame camera was a Canon 5D, and believe me more large pixels for greater tonality was very much a driving factor in what made that camera a classic of its era.

Rick “not theory” Denney
Forum: Pentax Medium Format 08-15-2020, 09:28 PM  
Old shooter with new 645D
Posted By rdenney
Replies: 79
Views: 6,312
Is the objective to have better memories or more memories?

Rick “suspecting different medications for each” Denney
Forum: Pentax Medium Format 08-15-2020, 09:15 PM  
medium format and dimensionality
Posted By rdenney
Replies: 46
Views: 3,448
Yes, but for any given print size, the Pentax image will have far more of those larger pixels, providing both the resolution and the tonal accuracy. And a proportionally larger print will project the same pixel size on the print, but in the midst of a much more expansive print.

The difference in grain size and number of grains between roll film and 35mm film generated the same effect. An 8x enlargement will look smoother than a 16x enlargement to make a 16x20 print from 6x7 and 35mm film. More grains per square inch of print without having to employ micro-grain techniques such as the use of 25-speed Panatomic-X. Plus-X has more tonal range but bigger grains, and 645ade use of the extra tonality without giving up the total number of grains. (Pan-F vs. FP-4 if your were an Ilford guy).

And the 4x enlargement from 4x5 sheet film took another big step in that direction, even if the sheet film was Tri-X.

Rick “who noted the effect in his own prints for the first time in 1976, comparing the lowly triplet-equipped Yashica 635 to a Canon F-1 with its superb 50/1.4 lens” Denney
Forum: Pentax Medium Format 07-28-2020, 05:29 PM  
medium format and dimensionality
Posted By rdenney
Replies: 46
Views: 3,448
The ability to smoothly represent the focus transition, which I think is at the heart of the 3D look, is a continuum. It’s just a matter of personal history where we set boundaries. Many large-format photographers draw that boundary between 4x5 and 8x10, and think of 5x7 as a compromise format. For them, 4x5 was the convenience format—reflected in its popularity with press photographers. Medium format has always been a compromise format, but there are those who describe 645 film as glorified 35mm.

But this is true: the difference between my full-frame digital cameras and the 645z are as startling as the difference between 35mm film and 6x7 film, notwithstanding that the physical difference is smaller. Neither can compete, of course, with 4x5 film, and I live in hopes (forlorn hopes, probably) of an affordable, field-usable, modern single-shot 4x5 back for my Sinars.

It’s also true that the 645z’s 44x33 is not only a great digital format, it’s also a great camera for photographers, and will take its capabilities basically anywhere.

Rick “depends a lot on printing technology” Denney
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