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Forum: Pentax Medium Format 3 Days Ago  
What is the state of Pentax MF??
Posted By rdenney
Replies: 28
Views: 1,504
Not as much as the 300!

Rick “who implemented a solution for that lens, however” Denney
Forum: Pentax Medium Format 4 Days Ago  
What is the state of Pentax MF??
Posted By rdenney
Replies: 28
Views: 1,504
The issue underlying all these silly threads about what Pentax isn’t doing accuse Pentax of not doing what others (Fuji, Hasselblad) are doing. All the requests for this or that new feature are tinged with the color of Pentax Must Do This To Stay Relevant. Sorry I colored your post with that tint.

A request for a lens so short relative to the frame diameter that it doesn’t exist in any format just seemed a bit off the wall.

Now, I own the first version of that Sigma 12-24, and have owned and used it for a very long time. Even on my 5D Classic, it’s good in the center but not sharp at all in the corners. But I didn’t realize there was a Mk II before the Art, which was apparently improved over my Mk I. Maybe it’s the Mk II you are describing. I still use it on the very rare occasion when I want something that wide, but even interiors lose geometric relevance when the lens is that short.

But Roger Cicala, who does I think the best lens testing in the biz, thought very highly of the Canon lens, with enough testing to resist a fanboy accusation.

https://www.lensrentals.com/blog/2015/02/canon-11-24-f4-l-mtf-tests/

I don’t own it, and the latest 16-35 would be in front of it in line. But the shutter is dying on my 5DII and I haven’t been willing to buy its replacement, now that I have the 645z, so I haven’t been lens shopping for Canon EF in a long time.

Rick “who overdosed on ultrawides a decade or so back” Denney
Forum: Pentax Medium Format 4 Days Ago  
Post your medium format photos!
Posted By rdenney
Replies: 14,028
Views: 2,370,638

Old Truck, Talkeetna, Alaska 2018. 645z, 45-85FA.

Rick “typical Alaska kitsch” Denney
Forum: Pentax Medium Format 4 Days Ago  
What is the state of Pentax MF??
Posted By rdenney
Replies: 28
Views: 1,504
What are you talking about? You want a rectilinear wide that is under 24% of the frame diameter for any format? The only good lens on the market I can think of that does is the Canon 11-24 zoom, but it’s 25% of the format diameter, not 24%. And it’s a zoom, so it isn’t limited to just the extreme wide end of its range.

A fixed-focal lens at 18mm for 33x44 would be such a narrowly specialized lens, I don’t know how many they could sell.

And the 25 has a FAR better reputation than that Sigma 12-24 used on full frame (I bought the Sigma maybe 16-17 years ago—the Canon blows it away, but the Sigma was all there was in those days).

The widest really good lens in that focal range is the Rodenstock 23mm HR-Digaron, which is designed for a maximum sensor size of 36x49, but with a 90mm image circle it might go large enough to approach a quarter of the frame diameter at small apertures. It’s a double-gauss design with only 16mm sensor clearance at infinity. The Fuji 23 is more retrofocus, and it’s a good lens. Hasselblad’s widest for the Pentax-size sensor is 21, and it’s deeply retrofocus. It’s cheaper than I thought it would be, but still in the same price class as the Pentax 25 back before they lost the supplier who could make the front element.

But 18? For 58x44?

Rick “people complain that the 28-45 is too heavy” Denney
Forum: Pentax Medium Format 5 Days Ago  
Post your medium format photos!
Posted By rdenney
Replies: 14,028
Views: 2,370,638

Garden Flower, Anchorage, 2018. 645z and 120/4 A Macro.

Rick “the bee was waiting patiently until I was done” Denney
Forum: Pentax Medium Format 5 Days Ago  
Post your medium format photos!
Posted By rdenney
Replies: 14,028
Views: 2,370,638
What I did was create a scratch area on my website (which is otherwise pretty outdated). My ISP provides something like 200 GB and I barely have scratched that surface. Normally, that area requires authorized access to see a file list. People can figure out or guess at filenames and find stuff, so this isn’t secure, and I never use it to store full-resolution or unprocessed images.

On my computer, I can use an FTP client to move files into that area, but then I have to remember the links. I have a trick for that, but it requires too many steps of preparation. There are other tricks, but all require that I name files meaningfully, which is another time consumer.

But I bought an FTP client app (FTPManager) for my phone that builds a thumbnail library locally (on the phone), and that makes all the difference. So, now when images are in that scratch area, I can see them and cut and paste the URL to that image with minimal editing.

To get images into that file area, I have to do it on the computer (though descriptive filenames aren’t required) it get the images onto my phone. If the image from the Pentax doesn’t need processing, I use the FlashAir app to download the image from the 64G FlashAir SD card in Slot 2. I save raw files to the 128G card in Slot 1, and JPGs to the Toshiba FlashAir card in Slot 2.

Once in the phone, I can use Desqueeze to downsample it, which does a pretty good job if I specify maximum quality in the JPG output. Then, that same FTP client will let me move a batch of them to my online scratch area.

If the image needs light processing, I can do that on the phone using Snapseed. But more often I’ll use DXO Photolab on the computer, and run a separate developing batch from the raw files targeted for lower-resolution 8-bit sRGB web display. Then, I can FTP it directly.

Then, in Tapatalk, I just paste the URL to the image between IMG tags. It’s easy to find the image visually, which was the missing link. The image stays out of both the Tapatalk and PF rendering engines, which is the key to maintaining image quality.

And I’m immune from policy changes at an image hosting service. My only problem with Ed’s images is that Tapatalk won’t resolve their URLs, and I have follow links to his image hosting service for each one. It’s usually worth it.

Of course, I pay for hosting my website, but I’d be doing that anyway. And that means my email server isn’t being mined for advertising.

It takes much longer to describe it than to do it.

Rick “who usually can’t play with images on a real computer while traveling, which is most of the time” Denney
Forum: Pentax Medium Format 6 Days Ago  
Post your medium format photos!
Posted By rdenney
Replies: 14,028
Views: 2,370,638
I’ve had trouble using Tapatalk as an image server. Even when I didn’t rescale the image, it chewed it up. Tex mentioned it wasn’t sharp, and that’s one thing my images from my recentish Alaska trip are is sharp.

But building online galleries on my own ancient web page makes new stuff visible with old, and I didn’t want the new stuff in that old gallery. So I put it where the sun don’t shine, but can link to images directly. These are not that small, and I hope the forum will reflect it without chewing it up, but as I said, this is an experiment.


Russian Orthodox Church in Eklutna, subsequently damaged by last year’s earthquake. 645Z, but I’d have to look up the lens—either DFA 55 or FA 45-85.

Edit: Seems to be working, but I haven’t seen it on a regular computer yet.

Rick “let me know if it looks bad on your end” Denney
Forum: Pentax Medium Format 01-12-2020, 09:30 PM  
What is the state of Pentax MF??
Posted By rdenney
Replies: 28
Views: 1,504
I haven’t had my Z long enough to even consider paying for a replacement. No additional features would do it, even if I wanted them.

IBIS is one I’d want. I do not need more pixels—I already can’t print big enough to use up the pixel density of the Z.

Full-frame? Appealing at some level, but only to get wider lens coverage. And the 28 is just about wide enough. Finding a25 would be cheaper.

Higher ISO? No biggie for me. But I don’t do Milky Way photos like Ed. I have made indoor photos at 6400 that were excellent—the equivalent of color negative film 5 stops slower. I’d rather put that money into a Gitzo tripod with carbon-composite legs.

Faster processing? Don’t need it.

Video? I’ve never used it.

But the Pentax has two things Fuji doesn’t: Proper optical SLR viewing, and cheap, excellent lenses. My 35FA is excellent, the 55DFA is superb, the 45-85FA is amazing, the 120 macro outstanding, the 200FA really good, the 400FA even better. All those together cost about what one Fuji lens costs, and as Tex mentioned, there is no secondary market. Getting those cheaply (I already had the 45-85 from the film era) made it possible to afford a used 28-45, which is an amazing lens.

Fuji makes cameras that are fun to walk around with. And they always have. But even back when they made the plastic fantastic Texas Leica, they also made the GX680 SLR for serious work. Not any more.

Pentax provides both Live View (the only viewing mode Fuji offers) plus through-the-lens optical viewing. Sometimes an SLR is a compromise, but sometimes not having it is a worse compromise for a given set of requirements.

I think in-camera one-button focus-stacking would be a great new feature. That would appeal to me more than the usual upgrade suspects. Focus on the near plane, press a button, focus on the far plane, press again, and the press the shutter and the camera takes it from there.

But I’d still have to wait until all you guys are kvetching about when Pentax would come out with the Z3 before the price would come into range on a Z2.

Rick “whose 645z is not quite 8% of the age of his newest 67, or 15% of the age of his N2, both of which make photos as well as they ever did” Denney
Forum: Pentax Medium Format 01-10-2020, 12:03 AM  
Is a 645D still worth buying?
Posted By rdenney
Replies: 29
Views: 1,335
Medium format cameras with glass prisms always have a bright finder, and an expansive one, too. The area being viewed is bigger, and requires less eyepiece magnification to get a the same overall effective magnification, which means a larger exit pupil in the eyepiece, which makes for a superior view.

My 645 N and NII focus very easily, and so do my 67’s. Of course, the N has focus confirmation, and so do the D and Z.

Generations of photographers accurately focused generations of pre-AF cameras. I reckon we can, too.

Rick “especially on a tripod” Denney
Forum: Pentax Medium Format 01-03-2020, 09:47 PM  
Do you trust your online storage?
Posted By rdenney
Replies: 68
Views: 2,153
Yeah, I built mine six or eight years ago from surplus bits including an ancient cheapie Dell MB and a (very nice) surplus IBM 8-disk controller that plugs into the 16-lane PCI-e slot reserved for a (then) fancy video card. But it is certainly out of date. Unraid now supports 8TB drives, while the version I use maxed out at five 4TB drives plus the parity disk. But mine continues to be big enough.



The Unraid system is built into a small Linux distro parked on the tiny USB thumb drive, which is set to be the boot disk. It reads from that drive only during boot. Though it has a keyboard and monitor, control is handled through an html interface. I can turn it back into a windows machine just by pulling the USB drive and rebooting.



But I need to upgrade my desktops to Win10 and I may rebuild this at that time.

Rick “the gig-e lan card is the key to this approach” Denney
Forum: Pentax Medium Format 01-03-2020, 12:25 PM  
Do you trust your online storage?
Posted By rdenney
Replies: 68
Views: 2,153
Yup, that was my first “PC”—a Kaypro 2 with the CP/M80 operating system (which fit in 8K) and 64K of RAM. I programmed in that machine first in Structured Basic and then in Turbo Pascal (the first commercial version). It had two double-sided drives and a 9” screen, making it much nicer than the contemporary (and similar) Osborne. I hocked my car to buy that computer.

Before that, I wrote programs for mainframes and for minicomputers like the Data General Nova 1200.

People my father’s age (90’s) and a little older were old enough to have programmed the first commercially available computers as adults. But a person at retirement age in the middle 40’s—nearly the age of my great-grandfather, could have done so, too, and could be six generations upstream of current programmers (I could have adult grandchildren at my age). Three generations is a claim that can’t even be supported with microcomputer programmers.

But Moore’s Law rolls along.

To the topic:

We lack sufficiently fast internet access to consider any online backup solution for our 2.5 terabytes of photo data. And over those generations, services come and go, and go not always with the notice and lead time a person might need to move their data.

So, I use online services only for photos I wish to display online. (On that topic, I’ve also found that all such downgrade the image unacceptably for the display of art photos, so I’ve decided I must place those on my own web site after doing all the downsampling and sharpening myself.) I’ve also found that many services do not resolve URLs correctly—for example I can’t see Ed Hurst’s photos when using Tapatalk. I use Tapatalk for documentary photos, but not for art photos, after Tex noticed a few of my Alaska photos being unsharp.

But storing photos on my own site is a pain, and that’s why I don’t post much of my own work here.

I may also use a cloud service for access to photos (for viewing only) on a variety of devices. I use iCloud a lot for that, for example. I always copy images to shared folders—I never use iCloud for primary storage, even it is not a free service.

But the originals are stored locally and not on the internet. I can always prove ownership, because anyone who steals my image will never have the full resolution image, but I will.

For backup, I use a 20-TB NAS server that uses the Unraid system. I make daily incremental backups and monthly full backups to that server using Macrium Reflect. Unraid uses a parity disk in the array, and can reconstruct any one failed disk. It also stores files in the whole, so even two failed disks doesn’t render the files on the remaining disks unreadable. I use it for serving music in my local network, too, though only MP3’s resampled from Flac files.

And once in awhile, I copy all my photo files to an external drive, which goes in our safety deposit box. That’s my protection from catastrophic physical failure, such as from a fire. I do that at least after every major project.

Again, I do not consider online services as primary storage—ever.

Rick “whose transparencies and negatives are more vulnerable that his digital files” Denney
Forum: Pentax Medium Format 12-25-2019, 03:18 PM  
Is a 645D still worth buying?
Posted By rdenney
Replies: 29
Views: 1,335
1. Value is something only you can determine. A bigger sensor with more pixels will get you some benefits, notwithstanding the improvements in technology for smaller sensors. This will be especially true at lower ISO values, and therefore for tripod work. But larger cameras are as much about the experience of using them as they are about absolute image quality, which exceed most people’s actual needs in any case.

2. Yes, but probably not quickly or cheaply. These are not spray and pray cameras. Most serious amateurs, if they push the button when they intend instead of just guessing, may not need more than 10,000 actuations in the life of their ownership.

3. Yes. See reviews on this site. Their use on a 645 is seamless when using the Pentax-made adapter, though you will be limited to aperture-priority metering and (of course) manual focus.

4. Yes, the FA lenses are top-shelf professional lenses from a decade or two ago, and they are nearly all excellent. See the reviews on this site. Yes, they operate on the D and Z just as they do on the N and NII. Focus is slower and they are not weatherproof. There is no shake reduction. But pros did without these things and got very sharp images.

5. Occasionally, but not for FA lenses and only rarely for manual-focus lenses. I did find a microprism focus screen for an NII that I put in my Z, which works fine.

Rick “rent one and see what you think” Denney
Forum: Pentax Medium Format 12-09-2019, 07:49 PM  
6x7 fungus
Posted By rdenney
Replies: 6
Views: 494
I would also blast it with ultraviolet to kill the fungus.

All lens faults either degrade the image unacceptably or they don’t. If pixel peeping and the overall image quality pleases you, then use the lens and enjoy it.

As with any flaw, make sure it is shaded. Off-axis light exposes flaws.

Rick “judging lenses by the images they make” Denney
Forum: Pentax Medium Format 11-15-2019, 07:52 PM  
Come on Pentax where’s next 645 !?
Posted By rdenney
Replies: 117
Views: 10,282
My 645z and 645nII were both bought new, as was my FA 45-85 and my three flash units and various other accessories.

I didn’t buy my 28-45 new—I let you do that :)

But Pentax could operate a refurbishment and certified pre-owned program that, with reasonable prices, could help capture secondary-market profits.

Rick “who buys new when it makes sense, but who would pay a premium to buy used from Pentax” Denney
Forum: Pentax Medium Format 11-10-2019, 03:31 PM  
Post your medium format photos!
Posted By rdenney
Replies: 14,028
Views: 2,370,638
Tuco’s graveyard brought this to mind from about ten years ago. I like his better.



Tombstones, Floyd, Virginia, 2009
Pentax 67, 55 “SMC Pentax”, on Fuji Reala.

Rick “not posting 645z stuff for complaints of lost sharpness” Denney
Forum: Pentax Medium Format 11-08-2019, 08:38 AM  
Come on Pentax where’s next 645 !?
Posted By rdenney
Replies: 117
Views: 10,282
No, it’s an Arsenal lens, made in Kiev—the glass comes from the Arsat 45/3.5, aka the Mir 26.

And that is the joy and the pain of it. Not sharp, but loved by users back in the day for its color rendering.

Rick “who has several” Denney
Forum: Pentax Medium Format 10-29-2019, 04:00 PM  
645Z -- Fine Art Photography :lol:
Posted By rdenney
Replies: 13
Views: 931
Have you tried it?

I have, and large soft boxes created specular reflections all over the paintings. Scrimming those out scrimmed out all the illumination. It’s hard enough with cross-polarized light.

Oil paintings are often glossy and highly textured. Glass-covered watercolors are easier.

But do what you want. Not my gig.

Rick “not a beginner” Denney
Forum: Pentax Medium Format 10-29-2019, 03:54 PM  
New 645z owner. What computing power am I going to need to handle these raws?
Posted By rdenney
Replies: 39
Views: 2,010
Which is why I suggested thinking through his RAID strategy carefully.

But there are ways to add redundancy without RAID. One is Unraid, which I use on my backup server. Unraid builds network share folders across drives, but does not split files apart. It also maintains a parity drive in the array. With those strategies, a failed disk can be regenerated, but even two failed disks will not make the files on the remaining disks unreadable. And it’s cheap.

If I wanted to take advantage of a 10G network, I’d have to think of something else—the consumer computers in that case can’t keep up. But I only make deep backups every month.

I do not make a thousand photos a day like some do. I’m careful with the button, and say “100 MB” to myself every time I fire the shutter. But as a long-time large-format photographer, I have never adopted a run-n-gun approach, even when I do events.

The new version of Unraid will, I believe, allow up to 40 TB of storage in its cheaper form. But it’s been a while since I built mine, and I’m not up to date.

Rick “mitigating, not eliminating risk” Denney
Forum: Pentax Medium Format 10-29-2019, 01:29 PM  
645Z -- Fine Art Photography :lol:
Posted By rdenney
Replies: 13
Views: 931
The standard technique for lighting is to use crossed polarizers, turned one way over the lights and then adjusted on the lenses to eliminate specular reflections from the artwork surface. Large light boxes make it harder, not easier.

The shorter the lens, the more reflections will be a problem, because reflected light will be admitted from a wider range of directions. Short lenses also have more vignetting, which will require correction in post.

I did a similar project using a P67 and a 135mm macro lens. You don’t need a macro lens for magnification, you need it for flatness of field. That said, the 55 DFA is sharp enough and flat enough, despite the reports that it has a curved field, at f/5.6. I wouldn’t go wider, even if it meant requiring art to be moved to a set to be photographed.

Rick “not an easy project” Denney
Forum: Pentax Medium Format 10-29-2019, 01:05 PM  
New 645z owner. What computing power am I going to need to handle these raws?
Posted By rdenney
Replies: 39
Views: 2,010
That describes my situation pretty well, though I was able to make a 1.5 GB image composition using Photoshop and Photomerge. I have 16 GB of RAM, a 64GB SSD for the Photoshop scratch file, and a 1.5 TB disk drive. That drive is starting to fill up, and I have an 8 TB drive ready to be installed. The processor is nearly a decade old now.

I make backups (daily, weekly, and monthly) to an external Unraid server with (currently) 13 TB capacity. The point of RAID is to increase speed by striping across multiple disks, not to increase reliability, so choose you RAID strategy carefully.

Rick “sustaining a FireWire interface for the Nikon scanner” Denney
Forum: Pentax Medium Format 09-23-2019, 09:21 PM  
6x7 advice
Posted By rdenney
Replies: 34
Views: 2,925
For the focal-plane shutter in a P67, it hardly matters. The closing of the second curtain is timed electronically, and the springs only control how fast the curtains move.

Rick “who lost touch for a few weeks” Denney
Forum: Pentax Medium Format 09-05-2019, 06:12 PM  
6x7 advice
Posted By rdenney
Replies: 34
Views: 2,925
Springs relaxed mean the shutter has been released. Cocked on a Pentax LS lens means that you have rotated the cocking ring to charge the shutter.

The focal-plane shutter on a 6x7 is cocked when you advance the film.

Rick “who never really worries about how they are stored” Denney
Forum: Pentax Medium Format 08-05-2019, 04:32 AM  
33-55 Lens Hood Differences
Posted By rdenney
Replies: 7
Views: 562
Those are frequently lost. I’ve lost several.

Rick “who leaves them at home now” Denney
Forum: Pentax Medium Format 07-25-2019, 07:59 AM  
Finding wide angle lenses for the 645 d
Posted By rdenney
Replies: 14
Views: 892
A. I don’t think the DFA lenses cover the film format, but others will know those details better than I. I guess I’ve never fitted my two digital-era lenses to my 645NII.

B. “Normal” is strictly a convention. Large-format photographers describe focal length as “short”, “normal” or “long”, just as a convenience for discussion. Perspective is entirely controlled by camera position, and focal length only controls how much of the scene will be included in the image from that position. For portraits, long lenses require longer distances (if you want more than just the subject’s nose in the picture), and when viewing a small piece of a scene from a long distance, perspective will seem compressed. But the lens is merely constraining possible camera positions, and camera positions are doing the work of perspective relationships.

“Wide angle”, “normal”, and “telephoto” have to do with lens design, not focal length in relation to format. Wide-angle lenses have wider coverage relative to focal length, which is needed by shorter lenses and larger formats. For SLRs, they are also retrofocus, meaning the distance to the rear node is longer than the focal length, which makes a short focal length possible in front of a deep mirror box. A telephoto lens has a distance to the rear node shorter than the focal length, making fitting on a shorter bellows possible. Normal lenses are often wide-angle designs to accommodate camera movements.

Fora camera like the 645z, I think in terms of short and long, and normal is just a convenient label.

Rick “not normal” Denney
Forum: Pentax Medium Format 07-25-2019, 05:52 AM  
Finding wide angle lenses for the 645 d
Posted By rdenney
Replies: 14
Views: 892
Learn lens lengths in relation to the film diameter. This is a model, and all models are false even though some are useful. This one is useful.

Those who have broad multi-format experience soon give up trying to equate focal lengths across formats, and instead learn what focal lengths are long and short for that format.

150mm is a format-diameter baseline for 4x5 large format, for example. And 75mm is half that while 300mm is twice that.

So, if 55 is the format-diameter baseline for 645 digital, then 23 is half that and 110 is twice that. Therefore, 23 on a 645D is like 75 on 4x5.

Likewise, 70 is the format-diameter baseline for 645 film, so 35 is half that and 140 is twice that.

Round to the nearest available lens. The 25 for the 645d is closest to the 35 for 645 film, if you can find (er...afford) one.

I have a 65 for 4x5, a 35 for 645 film, a 45 for 6x7, a 21 for 24x36, and a 12 for APS-C. All are half the format diameter or less. That’s why the lack of a lens in the 20-25 range for the 645 digital represents a hole. But the 28 end of the 28-45 has been useful enough.

When you change format shape, lenses feel different based on how you use that shape, but it’s more productive just to learn them through experience than to try to analyze it out.

Rick “format omnivore” Denney
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