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Forum: Digital Processing, Software, and Printing 09-04-2018, 09:32 AM  
Photoshop script to display K3 image focus points
Posted By fwwidall
Replies: 3
Views: 841
I was reading some old posts on the forum about creating a Photoshop Javascript script to display the focus points on a K3 image, and having zero experience of writing such things, and some time on my hands, I thought I'd have a go :)

I came across a script from 2010 called "ShowFocusPoint" by Malcolm Hoar for displaying focus points for Canon and Nikon images which I took as my starting point.

As I said I have zero experience in writing JavaScript so I'm sure the code could use a lot of improving. Hopefully we have some folks here who can improve it.

Here's a link to the script on dropbox (Windows only).

It uses the excellent 'exiftool' to extract data from the image so you need that installed. In the script you need to define the path to 'exiftool' and to a temp folder. It works in Photoshop CS6, and hopefully other versions.

The results for landscape and portrait images seem to differ, for some reason I have yet to figure out, but its close.

To run it open a K3 image file, go "File/Scripts/Browse", navigate to where you stored the script, and double click. After a while a new layer called 'FocusPoints' should have been created containing a representation of all the focus points as red '+'s and the in focus point as a green '[]'.

Hopefully you will end up with something like this...
Forum: Digital Processing, Software, and Printing 02-07-2017, 05:16 AM  
I hate Adobe (rant)
Posted By beholder3
Replies: 132
Views: 12,802
Adobe is just cashing in on the vast numbers of undereducated people, who are unable to make economic decisions.
Good for them, bad for the ...

There never was a real need to update LR more than every 3 years and you could buy the unlimited product for 80 EUR as upgrade.
That is 2.22 EUR/month. Most people never used let alone bought PS = 0 EUR/month. Or 0.07 EUR/day.

Now the ... are happy to pay a 500% price increase for a fully crippled product which will cease functioning if you don't feed it with your money.

Online and cloud make things easy to rent out software by the hour or day all without transaction costs.

If Adobe would not lie about their intentions, they would offer half day daily passes for their software (current fair value: 0,03 to 0,04 EUR). And nobody would complain if they raised the prices just like other products - that is inflation of +2%/year. So they could jump to 0,05 EUR/half day in about 40 years. ;)
How many half day Adobe passes would you need per year? 20? 15?

But in reality it is: Adobe Creative Cloud price increase coming in the UK | Photo Rumors
Forum: Pentax K-3 & K-3 II 06-21-2015, 10:54 AM  
Using K-5 focus corrections on K-3?
Posted By stevebrot
Replies: 15
Views: 2,450
What they said.

With your K-3 the task is easier since you can confirm with focus peaking in magnified live view. The trick is to separate random error from focus bias. I generally recommend that users do a simple evaluation before concluding that a focus adjustment is needed.* Using a flat** target at 20x the focal length distance and with the aperture set to maximum*** :
  • AF turned off

  • Manually de-focus the lens to the minimum focus distance

  • AF turned on

  • Acquire focus using the PDAF (non-live view) system

  • Turn AF off

  • Switch to Live View (focus peaking turned on)

  • Press the OK button to magnify to 100%

  • Evaluate whether the image is in focus and whether you adjust closer or farther to correct

  • Record "0" for no change, "-1" for closer, or "+1" for farther

  • Do the above steps five times

Repeat the above except with the lens de-focused to infinity. What the above flow does is provide a simple three-state statistical sampling of the AV results. A preponderance (4 or more) for any of the three possible results for the total of 1o focus attempts indicates whether there is a need to attempt calibration and whether you need to add or subtract. If you need stronger proof, add 10 more attempts for a total of 20. Note that for lenses having moving elements (zooms and/or internal focus), the results are specific to the focal length and/or target distance.

Should you determine that front/back focus exists, I would suggest making corrections in single increments. Checking the results using the above flow between increments. I know, it is tedious, but at least there will be a minimum of rework.


Steve

* My conclusion after reading literally hundreds of AF adjustment threads is that many (most?) users are chasing shadows and making things worse rather than better. As Jatrax so nicely put it,

As for myself, I have a single lens correction stored for my K-3 for my Sigma 17-70 (C), one which I intend to get rid of once I calibrate that lens using the Sigma dock.

** While the various 45-degree angle charts are quite popular and also very useful, it is difficult to use them to assess precision at a level smaller than the smallest increment on the chart scale. The fine adjustment on the camera uses smaller increments.

*** There is anecdotal evidence that the K-3 uses a less rigorous AF algorithm when the camera is set to narrower taking apertures.
Forum: Digital Processing, Software, and Printing 05-06-2015, 03:23 AM  
Any linux users around?
Posted By bobD
Replies: 41
Views: 3,928
Meet the Gimp is a lovely gentle series of video blogs that covers from basics to specialist uses...
The older shows are here...
Getting the older shows | Meet the GIMP!
Contents page for reference here...
Table of Contents | Meet the GIMP!

Current series here..
Meet the GIMP! | Video tutorials for GIMP and other free graphics programs
Forum: Pentax K-3 & K-3 II 04-26-2015, 04:15 PM  
Flash in the age of No Flash
Posted By jatrax
Replies: 4
Views: 1,528
Short answer is yes. I used x-sync adapters before I bought wireless triggers. You could use the x-sync port on the camera or buy a hot shoe mounted adapter that has an x-sync port. And a matching adapter for the flash.

But for the cost of wireless triggers I found they were much handier than the wired versions. You can get cheap wireless triggers for less than $50 and good ones like the Cactus for a bit more.

Here are some adapters: PC Sync & Hot Shoe Adapters | B&H Photo Video

---------- Post added 04-26-15 at 04:16 PM ----------

And here are the wireless triggers I use: Cactus Wireless Flash Transceiver V5 Duo DICFLAWFTV5D B&H Photo
Forum: Digital Processing, Software, and Printing 03-27-2015, 06:47 AM  
to update to PDCU v. 5.3.1 if I get the D FA 150-450mmF4 ??
Posted By k0og
Replies: 7
Views: 2,183
Greetings,

I just installed Digital Camera Utility 5 on my WinXP and Win7 PCs by following this procedure:

1) Download the latest update from the Richoh web site.

2) Rename an SD card or USB memory stick with the volume label "S-SW140" and keep it in your computer. The installer looks on your PC for that volume label to allow it to run.

3) Run the Digital Camera Utility 5 update installer from your hard disk, or the media you renamed - it makes no difference. There are two installers in the download, one for 32-bit and one for 64-bit, so use whichever is best for your PC.

It should install just fine, and you'll have the latest lens database. The utilty 5 seems to be functionally the same as 4 with a similar interface, but newer-looking buttons, so its use should be familiar.

-Joe-
Forum: Pentax K-3 & K-3 II 03-06-2014, 08:43 PM  
Pentax K-3 High ISO test.
Posted By dosdan
Replies: 107
Views: 13,394
Stagnant, the AR of your test image is 2.16:1. This indicates you've already cropped the original image. Can you please indicate whether this is a 100% crop, or what percentage of the original frame you cropped off the H & W of the original frame? When discussing the visibility of noise, the proportion of the frame used and any resizing is important.

See what I mean here: https://www.pentaxforums.com/forums/172-pentax-k-3/242969-sports-images-k-3-a-3.html#post2710908




BTW, any APS-C at ISO12800, unless resized to a quite small size, is going to look poor without drastic invention. ISO12800 is due purely to digital gain. (Analogue gain is not used at high ISOs because image shot noise at this level is, by far, the dominant noise source.) Compared to ISO100, you are using 128x gain. This means individual sensels have collected only 1/128th of the photo-electrons for the same rendering brightness level (e.g. the exposure was 7 stops lower due to the weak scene luminance level, requiring 7 stops more digital gain to produce the same image rendering brightness level) . So if a sensel holds 30,000 photo-electrons at FWC (usually defined as the 3% non-linearity point - November ) at ISO100, at ISO12800 that sensel will only be able to hold approx. 238 photo-electrons before the ADC clips.

Photonic shot noise (an intrinsic property of light and other forms of radiation) is the square-root of the number of photo-electrons. And the wanted-signal-to-shot-noise ratio is also the sq-root of the number of photo-electons. This means that, compared to ISO100, ISO12800 will have an 11.3x worse SNR (sq-root of 1:128), e.g. 173:1 (at ISO100; sq-root of 30,000) vs 15.4:1 (at ISO12800; sq-root of 238).
Forum: Pentax Lens Articles 08-12-2010, 04:24 AM  
Sticky: How to use/meter Manual & M42 Lenses on all Pentax DSLRs (K-1, K-3, K-5, K-30, etc)
Posted By Adam
Replies: 358
Views: 416,906
Many Pentax DSLR owners want to use M42 screwmount (Takumar) lenses, or M or K manual lenses, on their cameras because of the low cost and relatively high image quality of these lenses.


If you're wondering whether or not these lenses can be used with Pentax DSLRs (or the K-01), then the answer is yes! Pentax as well as third-party manual and screwmount lenses can easily be mounted on any Pentax DSLR (such as the K-1 series, KP, K-3 series, K-70, K-S2, K-S1, K-50, K-500, K-30, K-5 series, K-r, K-x, K-7, K10D, K100D, K200D, *ist D, etc.) Just follow this guide!



Modern Pentax DSLRs use the Pentax "K-mount", which employs a bayonet and therefore differs significantly from the M42 screw mount. The older manual M and K (SMC Pentax-M, SMC Pentax) lenses actually use the bayonet, so they will not need an adapter - you can skip straight to the lower portion of this article (starting at "Important!") for information on how to meter with those lenses. Screwmount lenses usually have "Takumar" in their names, and in order to mount screwmount lenses on your k-mount body, you'll need a Pentax k to m42 adapter. Pictured above is the genuine Pentax adapter, which is ideally the one you want to get. Similar third-party adapters are also available. Caution: Many third-party adapters, such as this one, have a protruding flange which will prevent you from focusing all the way to infinity. If you want to buy a third-party adapter (they're generally cheaper), make sure that they don't have this flange. Here's an example of a good third-party adapter.

Once you have your adapter, the next step is to install it on your camera (it can easily be put on and removed on-the-fly). Check out the m42 to k adapter manual.


After you've installed the adapter, you'll want to mount the lens. This is done by screwing it into the camera until the lens feels firmly attached. The focusing window and lens ring should line up with the camera just like any other lens. Now that your lens is mounted, let's talk about how to take photos with it.

Important! The hard part is to get the camera to actually fire when a manual lens is mounted. In order to accomplish this, enter your camera's custom function menu, select the "Using Aperture Ring" setting (usually at the end of the menu, #21 on the K-7, #27 on the K-5, #27 on the K-3, #26 on the K-1), and set it to 2 (allowed). Once you do this, the shutter will at least fire, as it wouldn't have with this setting disabled (you would simply have seen an F-- indication on the top LCD/info screen). The setting description should read: 'Shutter will release when aperture ring is not set to the "A" position' when "allowed" is selected. Also note that the mount on the lens must be conductive for electrical current so that it shorts the electrical contacts on the camera body. All Pentax manufactured lenses have a conductive mount, but some third party lenses do not in which case the area of the mount touching the contacts must be sanded down.

K-30, K-50, K-500, K-70, K-S1, K-S2 and K-01 users: make sure you also set your green button "action in M/TAv Mode" to Tv SHIFT. This is found under the button customization menu (page 3 of the main menu) on the K-01 or as a custom function on the K-30, K-50 and K-500. On the K-S2 and K-70, look under the e-dial programming sub-menu under button customization in the record menu.

Finally, ensure that auto ISO is disabled.

At startup, if your camera asks you for the focal length, enter the actual focal length as labeled on the lens. This will ensure optimal Shake Reduction performance. For zooms, you can use the lower end of the zoom range (this ensures that there will be no over-compensation), or the focal length that you shoot at most often.

Now, let's discuss metering. Since manual lenses don't feed aperture data to the camera, the only way for the camera to check how much light is being passed through the lens is to measure the light while the lens is stopped down. Follow this procedure to properly meter with a screwmount, M, or K lens:

___0. Ensure that the "Using Aperture Ring" custom function is set to "2 (allowed)" (K-30/50/500/01 users must also ensure that the green button is configured to Tv Shift in M/TAv Mode) as described above
  1. Set your camera to M mode using the mode dial (your camera won't fire in other modes*)

  2. Compose and focus your image.

  3. Using the aperture ring (the ring at the very back of your lens; it will have numbers such as 2.8, 4, 5.6, 8 written on it), select your desired aperture setting. Note that the smaller the aperture number is, the more light passes through the lens, and the blurrier the out of focus areas of your photograph will be (and vice-versa). Note your lens will not stop down until step 5.

  4. [Screwmount lenses only] Switch the diaphragm clutch on your lens to "Manual" (you can leave it on Auto when composing and focusing if you don't want a dark viewfinder).

  5. Measure the light by either pressing the "Green Button" (older bodies may use the Av button), or pushing your power button to DOF preview mode (only available on high-end bodies). Your camera will automatically set the shutter speed for you.

All that's left now is for you to press the shutter release button to take your photo. Congratulations- you've now learned how to use M42 and M & K manual lenses with Pentax DSLRs!

*Screwmount lenses may also be used in Av mode since they are always stopped down to the aperture you will be shooting at (unlike M&K lenses, which are stopped down only when the shutter is released or when you meter as described above).

Note: if your aperture ring has an "A" on it, instead of doing stop-down metering as per this guide, you'll want to set the ring to "A" and use the camera's scrollweel to adjust the aperture via Av mode.

Click here if you found this article helpful!

Video version:















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