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Forum: Flashes, Lighting, and Studio 2 Days Ago  
School Photography Equipment List
Posted By kaseki
Replies: 41
Views: 1,197
Batteries have some series resistance, part material and part chemical, so heating can be expected with heavy usage. If the depletion time due to heavy usage is shorter than normal charge time, they will be warmer than when being charged. This will be exacerbated by being inside a housing rather than partially exposed in a charger.

One advantage of the Cactus and many Pentax flashes is that they have a 330 Vdc supplemental power port, thereby allowing most of the battery heating to be external in the auxiliary power supply being used. The flash lamp and its circuit, however, are still being operated at a level that can lead to thermal shutdown. I'm sorry I can't report any data on that aspect.
Forum: Pentax Medium Format 2 Days Ago  
Pentax 645n pttl & Pentax 67ii ttl
Posted By kaseki
Replies: 4
Views: 172
I do have a 645NII manual, and there is no mention of PTTL, or of any Pentax flash that supports PTTL.
Forum: Pentax Medium Format 3 Days Ago  
Pentax 645n pttl & Pentax 67ii ttl
Posted By kaseki
Replies: 4
Views: 172
The 645N is old style TTL (flash is quenched when detectors looking at light reflected from the film being exposed determine illumination sufficiency). Multiple AF500FTZ flashes (among others) can operate in parallel using Pentax P5 cables. This is the same TTL concept that Nikon used back at the beginning of type F cameras.

The 645Z, and 645D, and most other digital cameras have difficulty consistently judging illumination sufficiency by looking a light scattered off of the photodetector array. Hence, in Pentax' case the PTTL scheme was hatched, wherein the flash lamps are flashed once for measurement and a second time for real. (I'm ignoring HSS here.) The AF540FTG flashes, as well as those of several third party contenders can perform PTTL. I believe that in PTTL mode, the FTG flashes can also communicate using Pentax P5 cables. There may be optical communication also, but I don't have any of these flashes so I haven't delved into their mysteries.

I believe all of the 67s are film type (I don't have one) and can be expected to work with original TTL.

I have no knowledge of Metz flashes.
Forum: Pentax Medium Format 5 Days Ago  
Post your medium format photos!
Posted By kaseki
Replies: 12,854
Views: 2,125,644
A horror movie starring The Yellow Creeping Crud is just begging to be made.
Forum: Digital Processing, Software, and Printing 6 Days Ago  
Darktable 2.6 is out
Posted By kaseki
Replies: 19
Views: 977
P.S. Some clarifying directions:

Flatpak Darktable was installed from Flathub?An app store and build service for Linux, but it seems that Software Manager recognizes it as installed by Software Manager.

The flathub link gets one the file org.darktable.Darktable.flatpakref

This is installed with the CLI command:





Code:

flatpak install flathub org.darktable.Darktable



within whatever directory it is stored

Then the permissions on /dev/shm need to be fixed as above followed by the flatpak run command as above.
Forum: Digital Processing, Software, and Printing 6 Days Ago  
Darktable 2.6 is out
Posted By kaseki
Replies: 19
Views: 977
Thanks for finding that.

Edit added 11Jan19
OK, having performed the CLI command:





Code:

sudo chmod 1777 /dev/shm



to fix the permissions problem, I could successfully perform the flatpak command:





Code:

flatpak run org.darktable.Darktable



Darktable 2.6.0 opened and once pointed to my test 645Z PEF file, opened it successfully. I closed Darktable, checked the Menu, and there was a Darktable entry there with its properties showing that it performs a flatpak call. Clicking this entry also starts Darktable 2.6.0. The test image seems to be the PEF high resolution file and not just the embedded jpeg thumbnail. Previously, DT 2.4.4 could not open that PEF file unless I used Raw Therepee to convert it to a TIFF file.

Now to learn rudimentary DT operation.
Forum: Digital Processing, Software, and Printing 6 Days Ago  
Darktable 2.6 is out
Posted By kaseki
Replies: 19
Views: 977
This seems to be a great idea. I hadn't heard of Flatpak. So I removed DT 2.4.4 and installed flatpak DT via the Software Manager. It thinks DT is installed. But wait, there's less.

Launching Darktable from the menu leads to nothing happening. Ditto from the launcher in Software Manager. Inspection of processes shows three modules related to Flatpak but none labeled Darktable. /usr/bin has three flatpak related files, all small, but no Darktable file. I must not be paid up somewhere. :eek:

Perhaps the DT PPA needs to be removed. Perhaps I need to reboot (shades of Windows!).

Edit: Attempting to install from the flathub website seemed at first to be successful, but attempting to run DT led to a complaint, viz.





Code:

bwrap: Can't mount tmpfs on /newroot/dev/shm: No such file or directory



It seems to be expecting a file system dissimilar to what I have.
Forum: Digital Processing, Software, and Printing 01-09-2019, 09:28 PM  
Darktable 2.6 is out
Posted By kaseki
Replies: 19
Views: 977
My interest is in DT 2.6.0 supporting xenial, not 2.4.4 supporting the latest liblensfun. Comments on his site do not address xenial, only the earlier Ubuntus, so the future status of DT vs. xenial is unclear. Anyway, I'll probably upgrade mint further when I get the time.
Forum: Digital Processing, Software, and Printing 01-09-2019, 02:11 PM  
Darktable 2.6 is out
Posted By kaseki
Replies: 19
Views: 977
Hmmmm. I just upgraded Mint 17.3 to 18.3 (xenial based), and de Bruijn's PPA is only supplying at this writing DT version 2.4.4 for the xenial version of Ubuntu per his information. This is confirmed by DT 2.4.4 being installed as a result of adding the PPA. I'm unclear whether (a) the xenial compatible version will be upgraded to 2.6.0 in the fullness of time, (b) I should upgrade Mint further to 19.x to get DT 2.6.0, or (c) with great agony, use the tar.xz file to build a version with unknown compatibility for Mint 18.3.

In any case, it seems that 2.6.0 will not be the result of upgrading through the PPA if one is using Mint 18.X.
Forum: Digital Processing, Software, and Printing 01-09-2019, 01:24 PM  
.dcp file compatibility between Lightroom and RawTherapee?
Posted By kaseki
Replies: 8
Views: 319
My first impression is that the white balance is different; the RT example has a gray instead of white table top and the center target white edge also looks gray. The LR counterparts are white.

The RT x-rite colors look less washed out. In particular, the lighting patches (middle rows, upper panel) show colors with RT similar to those seen when viewing my physical colorchecker.

However, even if my monitor were perfectly calibrated, the colors on an in-hand x-rite will look different depending on the room lighting (fluorescent, tungsten-halogen, xenon-metal arc or combinations thereof), so I don't want to argue that one or the other of the images is more color accurate.
Forum: Pentax Medium Format 01-09-2019, 12:42 PM  
Post your medium format photos!
Posted By kaseki
Replies: 12,854
Views: 2,125,644
Ivan:

In taking those, did you set the exposure high by a few stops to make the snow white instead of gray, or did you let the camera run its program mode without exposure offset and then fix the snow whiteness in post production?

kas
Forum: Flashes, Lighting, and Studio 01-04-2019, 03:28 PM  
School Photography Equipment List
Posted By kaseki
Replies: 41
Views: 1,197
I may have skimmed too fast to see an answer, but with respect to an earlier question -- a flash meter may be the fastest way to quickly discover the flash power setting needed for a replacement flash that yields about the same illuminance as the flash that is being replaced. Photographic consistency will somewhat depend on how well the two flashes have matched color temperatures and color temperature tracking with power setting.

I have a Minolta Flashmeter IV from ca. 1990 with many features that drove up its then price, but with modern tech significantly lower cost should be possible for basic measurements. The lowest price Sekonic that I noticed from a quick look at B&H's website is much less in constant dollars than the Minolta's price was.
Forum: Pentax Medium Format 12-25-2018, 06:11 PM  
Replace eye cup for Pentax 645 film
Posted By kaseki
Replies: 7
Views: 311
Do you have your small eyecup?
Forum: Pentax Medium Format 12-25-2018, 10:02 AM  
Replace eye cup for Pentax 645 film
Posted By kaseki
Replies: 7
Views: 311
What is missing from your photos seems to be the original eyecup, which for the 645N is the part that threads onto the assembly of your last (third) photo. This "eyecup" for the 645N is only 18 mm in diameter, and is essentially a rubberized threaded ring. (It is actually two parts, a rubber outer part and a metal threaded part.) The large eyecup's inner groove envelopes this original eyecup's rubber part. In other words, it is likely for the 645 that you need both parts, or all three parts if you take apart the original eyecup and count it as two parts.

Edit: Now that I see the directions just above, it seems that there are two different large eyecups. The 645N large eyecup seems to lack the attachment hardware and depends on the small eyecup for a flange to grab onto, at least on the 645N.
Forum: Pentax Medium Format 12-23-2018, 05:58 AM  
Post your medium format photos!
Posted By kaseki
Replies: 12,854
Views: 2,125,644
Remarkable. And as a nostalgic note, my second thought on reading this was recalling the movie "Invaders from Mars" ca. 1953, where the point on the ground surface where the invaders dug in was examined from afar using the Mt. Palomar telescope, operated at a somewhat more depressed elevation than I think is actually possible. 600 x 1.4 indeed.

P.S. Remarkably little apparent atmospheric turbulence effects; perhaps due to the time of day.
Forum: Digital Processing, Software, and Printing 12-20-2018, 08:25 AM  
Running Darktable and Lightroom 6 side-by-side?
Posted By kaseki
Replies: 18
Views: 662
I think it is conceivable that WINE or its commercial version Crossover Linux could support Lightroom. This might be determinable by visiting Codeweavers web site and looking at the compatibility list. Exactly how graphics are performed in Crossover is unclear to me, but Codeweavers Support staff could answer that. I know that I can run Windows-based Marine Aquarium 3.3 on my Ryzen/nVidia 1080Ti/LG 4k OLED TV system at 60 Hz with maximum fish under Crossover, and I think that requires the help of of the video card's hardware acceleration capability.

It may be necessary to read the camera's memory via Linux into a hard drive before using Lightroom if there is a Crossover USB interface issue.
Forum: Digital Processing, Software, and Printing 12-18-2018, 03:55 PM  
Running Darktable and Lightroom 6 side-by-side?
Posted By kaseki
Replies: 18
Views: 662
Some quick looking suggests that Virtualbox uses/provides virtual video drivers for different guest OSes, and as such one is limited to whatever Oracle thought was sufficient. The memory space in RAM is limited, and the user (as far as I can tell without a lot of research) cannot make use of the video card's processing. Thus while one might get the guest OS software to use the same ICC profile as the host OS, other goals such as getting 16-bit image data to a Quadra video card might not be achievable.
Forum: Digital Processing, Software, and Printing 12-17-2018, 03:06 PM  
Nice article about Linux and Photography
Posted By kaseki
Replies: 30
Views: 1,119
Thanks! I had wondered whether RT was multi-threaded.
Forum: Digital Processing, Software, and Printing 12-17-2018, 02:35 PM  
Running Darktable and Lightroom 6 side-by-side?
Posted By kaseki
Replies: 18
Views: 662
I'm pretty sure most OS installations will operate as minimal VGA until the correct drivers are installed. Mint can deal with nVidia gaming cards ab initio so long as the card predates that version of Mint. (Mint 18.1 onto a 1080Ti and Ryzen hardware system in the spring of 2017 was a bit messy.) I've never installed either Windows or Mint on a Quadra based system, so I don't know if the driver is available to Mint or a more limited setup process will occur until the system is pointed to the correct driver. Windows, I imagine, still wants the drivers to be installed locally, so an nVidia Quadra driver would need to be available on some readable medium, waiting for the inevitable insert driver disks now type message.
Forum: Pentax Medium Format 12-17-2018, 01:47 PM  
Post your medium format photos!
Posted By kaseki
Replies: 12,854
Views: 2,125,644
An architecture appearing to be tornado, sandstorm, and forest fire resistant -- should have applications in divers locations.
Forum: Digital Processing, Software, and Printing 12-17-2018, 05:47 AM  
Running Darktable and Lightroom 6 side-by-side?
Posted By kaseki
Replies: 18
Views: 662
Historically, it has been easier for the dual-booter to install Windows first, and then let the Mint installer construct the needed grub configuration so both OS appear in the start-up menu (along with memtest, etc.). I recently did just that after using ancient recovery CDs to reinstall Win7 on an Acer laptop so I could do CACTUS firmware upgrades. (The resulting Win7 after endless Internet activity has only a passing resemblance to the original.) Using a live USB of Mint 18.3 or whatever before the Win installation to do partitioning under gparted may be helpful if you plan for the partitions you want.
Forum: Digital Processing, Software, and Printing 12-12-2018, 10:24 AM  
Working with UHD 4K 100% AdobeRGB display - some questions
Posted By kaseki
Replies: 110
Views: 2,475
I use Crossover Linux (based on WINE), and have found that the least well replicated [WINE Is Not an Emulator :p] Windows function is communication with USB devices. For example, even after a lot of work affecting permissions and installing links into the "C-drive", I was never able to get the CACTUS software to communicate with the CACTUS flash device even though the Linux device handler could see the device and determine its characteristics. Crossover claims no support for USB devices.

After using my neighbor's Mac a couple of times for software upgrades, I bit the bullet and reinstalled Win7 using recovery disks onto an old Acer laptop shared with Mint 18.3. (The tiresome process of installing Windows should count as penance for some heinous previous-life crime.)

So, without someone asserting that he has BenQ software working under WINE (along with critical details), I would not want to assume that it works. VM Windows, however, is a different kettle of fish that I've never peered into.
Forum: Pentax Medium Format 12-12-2018, 10:05 AM  
Troubleshooting - 2 out of 5 blank rolls from 645NII / 120mm
Posted By kaseki
Replies: 12
Views: 461
I was wondering about that, but my cassettes have film in them so I'm a bit under-enthused about testing them. However, if the take-up spool is wound in the normal way with the film backing side out, it would behave the same. The feed spool is, I think, controlled by drag and not a pawl, so it might operate normally even though the film is passing over the roll instead of sharply up and over the platen from under the roll. I accidentally started to do this once and it was obvious that something seemed wrong.

For this setup to be realized, not only would the user have to install the film backwards while not noticing (maybe in a film changing bag), but the removed take-up roll would look different and he as well as the developing lab would have to not notice. Further, how would the initial winding to the arrow be possible if it was underneath the visible surface?
Forum: Digital Processing, Software, and Printing 12-11-2018, 07:48 PM  
Working with UHD 4K 100% AdobeRGB display - some questions
Posted By kaseki
Replies: 110
Views: 2,475
Unless I have misread something, if one wants to put the calibration matrix into the monitor's LUT memory, one has to calibrate using the BenQ software with a supported calibration sensor. Could a Linux fan be so lucky that this software can be operated under Linux? Or is one limited to depending on calibration aware programs to make corrections? Ref: Post 84 of this thread.
Forum: Digital Processing, Software, and Printing 12-10-2018, 02:01 AM  
Working with UHD 4K 100% AdobeRGB display - some questions
Posted By kaseki
Replies: 110
Views: 2,475
Thank you!

kas
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