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Forum: Pentax Medium Format 1 Day Ago  
The 'Z' on the CBS Sunday Morning
Posted By kaseki
Replies: 4
Views: 570
If the band is gold colored as it appears to be to me, then I think that identifies it as one of the "D" motion stabilized lenses. I don't own any, so I can't be more definitive.

Edit: After looking at the lens reviews 645 section, I have doubts that my premise is correct. It looks like some D lenses are not gold banded. So I'm going to guess
SMC Pentax-FA 645 45mm F2.8 from this site's lens data base.
Forum: Pentax Medium Format 2 Days Ago  
Post your medium format photos!
Posted By kaseki
Replies: 13,399
Views: 2,222,775
645Z camera jpgs using FA 120mm macro. No post processing, although the white one in shade could tolerate some exposure adjustment if one didn't want it to look like shade.
Forum: Flashes, Lighting, and Studio 3 Days Ago  
Ultrasounds out of the flash
Posted By kaseki
Replies: 9
Views: 389
The ear plug suggestion is probably your best bet. However, to be complete one other idea occurs to me.

Many Pentax flashes (but I am not familiar with the 201FG) and even Cactus flashes have a port where an external HV power supply can be attached. As it happens, the Quantum Turbo batteries can be used to perform this function (with the correct interconnecting cable). The earlier version of these Quantum units (serial numbers below Kxxx, I think, but this needs to be checked) do not pulse feed the flash, but apply a dc voltage that rises with the flash capacitor charge. Hence, the switching power supply primarily charging the flash is not at the flash, but in the Quantum Turbo battery pack. I'm too old to do an ultrasonic test drive for you, but I vaguely recall the acoustic noise to be in the normal hearing range and relatively unobtrusive.
Forum: Flashes, Lighting, and Studio 3 Days Ago  
cactus v6ii : multi vs pen FW
Posted By kaseki
Replies: 7
Views: 265
I'm not completely clear about all of your issues; I would probably have to study your message for a while. Also, others here have vastly more experience with earlier Cactus units. What I think I know is that the Pentax compatible software loaded into the V6II allows it to communicate with Pentax digital cameras and also pass through Pentax commands to a 360 or 540 flash mounted on top of the V6II. The RF60X flashes that work with the V6II can perform Pentax compatible P-TTL and HSS flashing. I'll defer to others here all other combinations of Cactus units, 3rd party flashes, and non-Pentax related Cactus software.
Forum: Digital Processing, Software, and Printing 5 Days Ago  
Calculating Printing Costs
Posted By kaseki
Replies: 6
Views: 426
You might check out the resources listed on this page: Cost of Inkjet Printing Reports by Red River Paper
Forum: Digital Processing, Software, and Printing 5 Days Ago  
**The Great Cloud Backup Storage Post**
Posted By kaseki
Replies: 62
Views: 2,024
Perhaps there is a market for being "chipped" with an embedded device with which one can read and write large volumes of data -- a device sized more like a pacemaker than an ID micro-chip. "We have the technology." (Six Million Dollar Man)
Forum: Photographic Industry and Professionals 5 Days Ago  
Camera marketing jokes
Posted By kaseki
Replies: 21
Views: 1,089
I will restrain my unbounded curiosity until I can research the topic more thoroughly than the half-hearted stab I made today.
Forum: Pentax Medium Format 5 Days Ago  
Post your medium format photos!
Posted By kaseki
Replies: 13,399
Views: 2,222,775
Nice shot. Recalling my single-digit-age childhood, there was a merry-go-round (carousel) on the VA side of the falls. Some searching suggests it was lost in a flood. Any ruins remain? (I'm referring to the type with wooden horses and calliope, not a playground device.)

I also remember the scary hike over part of the falls on the MD side, which Google maps informs me is the Olmsted Island Trail.
Forum: Photographic Industry and Professionals 5 Days Ago  
Camera marketing jokes
Posted By kaseki
Replies: 21
Views: 1,089
One would expect that a Fresnel lens, even a perfectly constructed one, would have higher aberrations than a smooth surface lens of the same base curvature, and this would be further degraded off-axis where the side walls of each annular section are included in some of the light paths. Computational post-processing may be able to address much of this, but (a), surely it is not presently in all cameras that might use the Fresnel lenses, and (b), even with extravagant processing, there would be some residual effects that might show up as haze or blur. Without seeing actual measurement results showing Fresnel lens effects can be made negligible, I wouldn't myself recommend Pentax leap into that pit. And my Pentax systems have the most weight to lose. [Obligatory joke]

In the above comment, I want to note that I am not considering a diamond turned lens to be a Fresnel lens, because diamond turned lenses have annular cut widths smaller than the wavelength of the light being refracted, thereby minimizing in-band scatter, and in their case I think the summation integral of the point spread function is pretty much additive into the desired circular aperture PSF, at least insofar as pixels 10X the wavelength can measure.
Forum: Digital Processing, Software, and Printing 6 Days Ago  
The Darktable Users Coterie
Posted By kaseki
Replies: 65
Views: 4,618
Here is my first attempt to test Darktable by actually doing something. And what it (and I) did using the filmic module following the Ep. 26 Darktable video of Bruce Williams may be seen comparing the following three pictures, all from an image taken last summer of a Catasetum "Dragonstooth" [orchid] female flower cluster. The conditions were direct sunlight with the 645Z aimed semi-upwards into the flower cluster.

The upper picture is a Darktable generated JPEG file taken directly from a TIFF file generated using Raw Therapee to convert from the PEF file. (At the time of conversion last summer, Darktable could not import PEF files.) Whatever was automatic or nominal or default was used for this purpose in RT. (At that time, RT used the PEF embedded JPEG file to infer white balance.) The middle picture is a JPEG file generated using Darktable after post-processing the PEF file using the steps in Bruce Williams video. The bottom picture is a Darktable generated JPEG taken directly from the PEF file without any post-processing other than whatever is default in DT.

Relative to the upper RT-converted image, the DT images seem to have been subjected to a weather change. But beyond that, the filmic version (middle picture) is only subtly different than the relatively unprocessed lower (pre-filmic) picture. Perhaps that is to be expected. Or perhaps some aspects of filmic and other modules were engaged without me knowing.
Forum: Pentax Medium Format 06-10-2019, 08:47 AM  
Slow shutter on 645Z
Posted By kaseki
Replies: 10
Views: 530
Because there is no electrical communication between the lens and camera, and also because of my heartfelt hope that there is nothing wrong with the camera, the only remaining aspect that I can see is the mechanical connections related to the iris. And because the other 67 lens works OK with the adapter, then I would put on my +4 diopter glasses and carefully inspect the two lenses mechanical interfaces for any differences. For example, are both the "suspect" lens' iris interfaces free of any bend or wear relative to those of the "good" lens? Does rotating the aperture setting on the "suspect" lens always cause the related lever to move correctly on the adapter's camera interface?

With the "suspect" lens on auto, and the camera ON, fixed ISO, and in some aperture priority mode, does the estimated exposure time shown in the viewfinder with a half shutter button press change as the aperture setting on the lens is manually changed? (I'm not sure of this one as I haven't tested it, but somehow the iris setting has to be known without an electrical reading, and this knowledge has to be obtained either before or during exposure for the camera to set the exposure time.)
Forum: Pentax Medium Format 06-09-2019, 08:59 AM  
Slow shutter on 645Z
Posted By kaseki
Replies: 10
Views: 530
The adapter manual says it better (but perhaps less than optimally). See below. In other words, the intended aperture has to be set manually; there is no "A" setting. However, the iris stays open until the camera forces the iris closed during the image taking process if the switch is set to Auto.
Forum: Pentax Medium Format 06-09-2019, 08:39 AM  
Slow shutter on 645Z
Posted By kaseki
Replies: 10
Views: 530
The 67 lenses have to be in "Auto" aperture mode to work correctly with the 645, I believe I have read somewhere. The Auto/Manual selector on my two 67 lens examples suggests that the intent was to have it fall out of Manual with the least of effort. However, what I can't easily evaluate is what is actually going on in the lens when it and an adapter are connected and on-camera. Mine seem to work OK.

Beyond Chris' good advice above, you might check that your suspect lens has both its axial lever and radial iris tab functioning correctly without binding, and that this carries through to when it is connected to the Pentax adapter's two lever arrangement.

Edit: W.r.t. Phil's comment, the Pentax (and Fotodiox) adapters carry the iris drive and iris report connection to the 645.
Forum: Photographic Industry and Professionals 06-08-2019, 04:03 PM  
Nikon recommendation: sell! sell! sell!
Posted By kaseki
Replies: 85
Views: 3,488
The issue with Betamax wasn't not adapting to change. Sony, already in the transistor TV business that RCA (remember that name?) wouldn't embrace because their new tube plant hadn't paid for itself yet, invented Betamax and refused to license it to the other companies diving into the surging interest in TV video recording. So Sony's competitors came up with a less expensive (and lower quality) scheme called VHS. I won't waste everyone's time on the merits of Betamax and and Sony's video recorder capabilities by the time the SL-2700 was manufactured, but rather than a Darwin example, as manifested by RCA, what occurred to Sony was a technology example of Gresham's Law: The bad drives out the good (originally applied to coinage).

In other news, Sony spent a lot of effort bringing R, G, and B OLEDs to some level of maturity for use in flat panel TVs. But LG has taken over most of that market by using single color OLEDs with white phosphors and color filters. Sony likely can never reach LG's manufacturing cost for an acceptable TV screen even if their emitters have better color purity.

The second mouse gets the cheese.
Forum: Flashes, Lighting, and Studio 06-05-2019, 04:57 PM  
Advice needed for lighting options
Posted By kaseki
Replies: 18
Views: 607
The ceiling appears in the image above to be some other color than white or pure gray. The reflected light may have a color cast that is difficult to correct, given that some of the lighting is daylight.

The floor is another issue if reflections from it provide any significant lighting support to the models' skin surfaces, particularly when a ceiling is the light source. Depending on measurements, I would consider rolling out some black background on the floor, or maybe white or gray background. Beauty dish like reflectors can then be positioned to reflect what is available from the intended light sources upward.

Don't forget extension cords, gaffer tape, sandbags for tripods, and maybe even bricks for scrims, background papers, etc.
Forum: Flashes, Lighting, and Studio 06-05-2019, 09:31 AM  
Advice needed for lighting options
Posted By kaseki
Replies: 18
Views: 607
There are two methods I have used in my minimalist rate of photo generation over the years. In one method, a flash on the camera is used to trigger other flash detecting speed lights or to trigger small devices that can be purchased that generate a switch closure upon seeing a flash. The switch closure is wired to studio light type flash lamps.

In the second method, the camera is wired to flashes designed to work with the camera wired connection. In this context, I'm referring to Pentax flashes and the 5P cable system. For film cameras using TTL, all the flashes can be quenched at the same time providing the desired TTL light level as well as proportionate output determined by flash settings, gobos, and distances. For P-TTL, it is not clear that this can be done, and the 645Z manual does not address multiple flashes except via using Pentax' optical communication system among flashes. However, Cactus V6II and RF60X combinations (and some others I forget) operate by RF and can be made to do multi-light P-TTL or multi-light manual flash.

These schemes require either compatible flashes, or not so compatible flashes and supporting equipment, mostly cables and flash detectors. Your camera store should be able to advise you.

res secundae
Forum: Pentax Medium Format 06-05-2019, 09:10 AM  
Lightroom Alternative
Posted By kaseki
Replies: 22
Views: 1,318
Raw Therapee and Darktable are "free" and can convert PEF to TIFF. RT reportedly uses the inferred white balance that generated the embedded JPEG files to convert the raws; I'm not sure what Darktable does. Also DCU5 that comes with the 645Z will certainly read the PEFs. I didn't try conversion yet, so I can't testify that it can generate TIFFs, but what good would it be if it couldn't?
Forum: Digital Processing, Software, and Printing 06-05-2019, 04:08 AM  
**The Great Cloud Backup Storage Post**
Posted By kaseki
Replies: 62
Views: 2,024
Please see Google may have taken this whole 'serverless' thing too far: Outage caused by bandwidth-killing config blunder ? The Register for today's version.

In any case, I recommend server quality drives (I use WD HDs with a Y in the part number) for storage either in a NAS or USB connected backup box. As clackers notes, one can support any level of paranoia by rotating drives and storing them in uncorrelated (disaster-wise) locations. You pick the disaster you consider the worst case. A local fire is different than a section of your state falling into the sea after an earthquake, which again is different than the Yosemite Caldera destroying the central USA. Of course, disasters that aren't personally survivable may not matter unless one is an international corporation.
Forum: Flashes, Lighting, and Studio 06-05-2019, 03:49 AM  
Advice needed for lighting options
Posted By kaseki
Replies: 18
Views: 607
If you had sufficient time, I would suggest one of the Photek large umbrellas with diffuser for whole body shots. But maybe laying out white sheets on the ground and as curtains might keep some of your flash power where it is needed.

While one's lighting set up can be limited only by one's imagination, common practice documented in innumerable books and pamphlets related to portraits suggests at least three lighting sources (of one or more strobes), four under some conditions, except where deliberate shadowing is desired. In the latter case, some daylight plus a flash with a snoot may be sufficient. I would think that flash rental in addition to using your own flash may be needed, and that having or renting a flash meter will be essential to setting the light levels of each. This isn't my profession, but I would also guess that some (a lot of) set up and experimentation may be called for in your remaining time before the models arrive. Best of luck.
Forum: Flashes, Lighting, and Studio 06-03-2019, 10:28 AM  
AF-540FGZ head a bit loose?
Posted By kaseki
Replies: 4
Views: 231
OK, if we must design something I suggest the following:

First, note that there is a flat surface under the Pentax Corporation sticker on the levered front part (flash head part)
Second, whittle a piece of wood or plastic that is an appropriate length for the angle desired to wedge between this flat surface and the top edge of the lower assembly
Third obtain a few rubber bands (elastics in the UK) that are thick but fairly small in circumference. US 3.5-inch size would be about the upper circumference limit. Use these to keep the wood/plastic block in place.

Alternatively, for a quick stab at a solution, a built-up multilayer gaffer tape or masking tape wad on the tubular section the flash head rotates around might also hold if the weight of the diffuser is not too great.

I notice on my recently obtained used unit that the push button at the hinge point doesn't seem to affect the rotation. Perhaps the mere act of forcing the head without pushing the button -- a button missing on earlier units and perhaps ignored by owners -- breaks something that would otherwise resist diffuser droop.©
Forum: Pentax DSLR Discussion 06-03-2019, 06:46 AM  
Sticky: Pentax Proud Owner Signature Banners : K-3, K-5 II, K-30, and many more!
Posted By kaseki
Replies: 297
Views: 214,350
I just jointed my two banners into one image using Gimp, which is the app I used to build the "N" image from the "Z" image.
Forum: Flashes, Lighting, and Studio 06-01-2019, 08:46 AM  
AF-540FGZ head a bit loose?
Posted By kaseki
Replies: 4
Views: 231
You might trawl YouTube to see if anyone has a video on repairing these particular flashes. If so, it may become apparent whether there is a means of tightening.
Forum: Pentax Medium Format 06-01-2019, 06:49 AM  
Come on Pentax where’s next 645 !?
Posted By kaseki
Replies: 65
Views: 3,583
My perspective: Given the modern ability to stitch together images in post processing -- images potentially taken with medium-angle lenses that can always beat ultra-wide-angle lenses in lower non-uniformity, aberrations, and distortions -- ultra-wide lenses' role would seem to be more limited than before the age of massive processing power on one's desk. Ultra-wide angle might now only be necessary for certain dynamic scenes that wouldn't be normally taken with long telephoto lenses -- perhaps billowing sails seen from the sailboat's deck, huge flocks of flamingos taking flight, etc. My perspective should not be taken to infer that as a hobbyist, I would not enjoy a lens with an unusual quality; I do have an Arsenal fish-eye for my 645s, for example. Even more "fisheye" field width could be of interest (at used lens prices). But where does the desired scene boundary stop? Do I need 645 resolution when one of the Ricoh devices could provide an extreme image width for a single shot?

Some very nice stitched panoramic examples may be seen in Glenn Randall's book, The Art, Science, and Craft of Great Landscape Photography.
Forum: Pentax Medium Format 05-27-2019, 04:05 PM  
Post your medium format photos!
Posted By kaseki
Replies: 13,399
Views: 2,222,775
Micro apple tree in bloom, and a close up. Apple like fruits developing later are about 6 mm in diameter. Photos desperately needed something to show scale, but no bees cooperated.
Forum: Pentax Medium Format 05-27-2019, 09:19 AM  
Sudden 35mm f/3.5 focus alignment problem
Posted By kaseki
Replies: 3
Views: 392
I just looked at mine. It appears that the rear element is supported by some soft material. Also, the overall design appears to be fairly complex and going at it with optical ring spanners might be an experiment in how to permanently disassemble the optics group and supporting mechanical parts. I can only suggest finding a shop that repairs or even just cleans the interior lenses of Pentax lens assemblies. They would know how to take it apart. Perhaps that is all that is needed to reset the support into its proper position. Cost may equal buying another used 35mm on eBay, however.
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