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Forum: Pentax K-3 07-27-2014, 02:46 PM  
4K timelapse "bug"
Posted By procyon
Replies: 13
Views: 1,586
Exactly - but to be honest I can do one thing - write about it somewhere where people who might use that themselves will see it and hopefully find out about it's shortcomings beforehand ;)
Which is what I kind of said twice in my first post ;)
Forum: Pentax K-3 07-27-2014, 09:01 AM  
4K timelapse "bug"
Posted By procyon
Replies: 13
Views: 1,586
I know that there are better solutions and I have used them - it doesn't change the fact that this particular implementation is severely braindead.
Also I don't get why I would want to change the JPG quality level? Even if that makes the file smaller it would lower the quality which is not something I would want.

Regarding the comments about quality - what kind of issues did you notice? Is the downsampling to 4K bad (i.e. aliasing, artefacts) or the JPG compression in the MJPG too strong (I saw frames of about 2MB inside the AVI)?
Forum: Pentax K-3 07-26-2014, 04:11 PM  
4K timelapse "bug"
Posted By procyon
Replies: 13
Views: 1,586
The issue is not that it takes less pictures than expected - it takes the correct amount of pictures - but then duplicates them twice to make an impression of more frames. It would be faster to just not duplicate and write one frame per one "click" of shutter :)

---------- Post added 27-07-14 at 02:13 ----------



Ok, sad to hear that - guess it's here to stay then. Oh well - time to invest in even bigger SD-cards then I guess :p
Forum: Pentax K-3 07-26-2014, 01:44 PM  
4K timelapse "bug"
Posted By procyon
Replies: 13
Views: 1,586
Just played around with the 4K timelapse functionality and writing this just in the hope that someone else might find it useful :)
Basically the 4K timelapse (that you can activate in movie mode by pressing the "Up" 4-way controller and selecting "Interval Movie Record") records it's output in an AVI file with MJPG (Motion-JPEG) compression. I did a 15 min recording with picture taken after every 2 seconds.
That should give me 15min * 60 (sec/min) / 2 = 450 frame video.
What I actually got was a 1353 frame video that was at 24fps and about 56 seconds long.
Since this was somewhat unexpected I investigated a bit and I can clearly see that each and every frame was in the output file 3 times.
There is no difference whatsoever between those frames.
MJPG is not like MP4 or other common compression methods that compare frames to the previous one and can compress identical frames a lot so sadly this means the file is actually 3x larger than it has to be. In reality the output is a 8fps video with frames duplicated twice to look like 24fps but it gives absolutely no advantage.
It's fairly easy to get rid of those duplicate frames completely (and without any loss of quality) by using for example VirtualDub and setting "Direct Stream Copy" and "Process every 3rd frame".
Pity though that such a waste of time, card space etc. was deemed necessary by someone.

My personal guess why it was done like that:
Likely 24fps was chosen for the timelapse as the lowest commonly used standard framerate (lowest is better as we all want our pretty timelapses to last a long time) - and then likely someone higher up the corporate ladder complained that their resulting timelapse was too short :p I know it sounds stupid but it's such a stupid "feature" - ok, bug as I wrote in the title already - that I just can't think of a better reason.

Hope it might be helpful for someone else who uses this feature.
And I know that "pros" just shoot pictures and convert them to video on the computer, not in-camera because that gives more creative freedom etc. :)
Forum: Weekly Photo Challenges 01-20-2014, 01:03 AM  
Weekly Challenge Weekly Caption Contest January 20 to January 27, 2014
Posted By procyon
Replies: 64
Views: 5,408
Shake reduction??? Do you think I'm some sort of a bush?!
Forum: Mini-Challenges, Games, and Photo Stories 04-11-2012, 06:30 AM  
Photo Scavenger Hunt Game Continued - Part II!
Posted By procyon
Replies: 15,488
Views: 810,475
Well, since no one hasn't posted anything yet I'll offer this picture of Colmar, France.
Though not the main subject you can see several potted plants here


I would like to see a landscape shot made from a ship/boat
Forum: Film Processing, Scanning, and Darkroom 02-15-2012, 01:28 AM  
Simple and effective ION scanner
Posted By procyon
Replies: 15
Views: 6,521
Kind of nitpicking isn't it :p
To be even more precise we have to also consider that most uncompressed formats also pad the size of pixels to be 32 bits although there is only 3 channels x 8 bits per channel = 24 bits actual information (those extra 8 bits are in some formats used to store transparency/alpha information).

Actually uncompressed formats are not very common as output for any consumer device nowadays. Even RAW files are compressed (though mostly losslessly). I know that there used to be cameras that could shoot tiff files. I wonder if those were uncompressed or used one of lossless compressions available for tiff.

About the quality of pixels - I know some sh***y devices use low pixel count sensors and then extrapolate this to some higher resolution. Webcams used to do that a lot at some point (Big advertising text "X MP still pictures" with tiny warning about being upscaled from lower resolution). I haven't seen that a lot recently. Hopefully the ever increasing pixel density on sensors has made it unneccesary.
Forum: Film Processing, Scanning, and Darkroom 02-14-2012, 01:05 AM  
Simple and effective ION scanner
Posted By procyon
Replies: 15
Views: 6,521
File sizes in megabytes have nothing to do with megapixels. If the files are smaller then they either contain less detail (and thus compress better) or are more heavily compressed.
Forum: Non-Pentax Cameras: Canon, Nikon, etc. 02-14-2012, 12:38 AM  
Lytro
Posted By procyon
Replies: 16
Views: 1,967
Yeah, I know. Just an example of a starting point. It should certainly be several magnitudes better for a realistic effect.
Forum: Pentax DSLR Discussion 02-13-2012, 07:07 AM  
How do we compare Dynamic Range and Color Depth on picture?
Posted By procyon
Replies: 3
Views: 2,038
I personally don't think there is a diference, as digital cameras really do produce only numbers, but I can respect other opinions on that.
My non-numerical interpretation of dynamic range - how much you can brighten up shadows without nasty noise appearing, and how much you can recover highlights without flat detailless areas appearing (I use Lightroom so it's "Fill light" and "Recovery" respecively). There is no way to define "nasty noise" without going to numbers and mathematics, "flat detailless areas" are a bit easier, as you can visually identify them.
Forum: Pentax DSLR Discussion 02-13-2012, 06:27 AM  
How do we compare Dynamic Range and Color Depth on picture?
Posted By procyon
Replies: 3
Views: 2,038
You already mentioned DXOmark.com, their webpage has a thorough explanation of how they do it - DxOMark - Measurements
Forum: Non-Pentax Cameras: Canon, Nikon, etc. 02-13-2012, 06:11 AM  
Lytro
Posted By procyon
Replies: 16
Views: 1,967
I can certainly see the facebook potential. And that of course equals money.
Now if they invented paper that you can use to print those pictures - that would be something! (For example change focus by tilting the paper gently, you know like those stripy thingies where you can see two different images depending on the viewing angle, but I'm thinking of more like 10+ different focus planes on paper)
Forum: General Talk 02-13-2012, 06:01 AM  
Poll: Camera at a funeral
Posted By procyon
Replies: 37
Views: 2,899
I have done it once on the request of the closest relatives of the deceased. It was a very stressful and emotionally hard thing to do.
I certainly can't imagine doing it often. Probably would require someone with a very appropriate mindset.
Pulling a camera out on a funeral without a specific request is not something I could do without feeling like I would be jumping on the lid of the coffin or someting like that.
Forum: Troubleshooting and Beginner Help 02-13-2012, 05:44 AM  
Idiot's guide to extension tubes
Posted By procyon
Replies: 3
Views: 1,536
Yes, exactly.
It's certainly not impossible to use manual tubes, I have used them without problems, it's just good to know that chasing butterflies is not an option.
Forum: Troubleshooting and Beginner Help 02-13-2012, 05:27 AM  
Idiot's guide to extension tubes
Posted By procyon
Replies: 3
Views: 1,536
If you just use an M lens on a camera in M mode, then you can still focus and compose with the aperture fully open and bright, but with manual extension tubes when you change the aperture it actually changes immediately.
That leaves you two possibilities (unless of course you only shoot with aperture fully open all the time):
1. Stop down and then focus with the quite dark viewfinder.
2. Focus with the aperture fully open and then close it down trying not to move the camera in process (doable on a sturdy tripod and static subject).
Forum: Digital Processing, Software, and Printing 02-13-2012, 04:47 AM  
Linux Photography Applications
Posted By procyon
Replies: 19
Views: 4,314
I filed this bug support.bibblelabs.com - View topic - Clipped highlights with strong colour cast even longer ago. I guess Bibble/AfterShot just doesn't "get" Pentax. Btw. since I received no resolution to my problem for a long time I fiddled around a bit myself and found out that they actually use camera white balance in processing that happens in their pipeline before any of the controls available for the user .... so much about RAW being camera settings independent. (If anyone wants a longer explanation I am happy to give it). Anyway I moved away from them and would recommend anyone else to do the same.
Forum: Pentax K-5 02-01-2012, 05:50 AM  
newbie question - flash exposure compensation
Posted By procyon
Replies: 11
Views: 1,742
I know that with M lenses the built in flash always fires on maximum.
Don't know about the A lenses (because my only A lens is a fisheye and I haven't tried with it), but I wouldn't be surprised if it would also be the same for them.
Forum: Digital Processing, Software, and Printing 02-01-2012, 04:26 AM  
Looking for Pentax K-r Camera Calibration Profile for Lightroom
Posted By procyon
Replies: 12
Views: 5,923
Are there any photo studios near you that have it?
If yes then you can take your dog/friend/spouse for a photo session and in the process also make a profile for your camera (It will of course be only accurate in lighting close to studio lights - that means normal daylight, but it is certainly not worse than using a photo shot with someone elses camera in some random lighting).
Forum: Pentax K-r 01-06-2012, 08:24 AM  
why adjust sensitivity?
Posted By procyon
Replies: 31
Views: 2,892
If you try to brighten shadows in underexposed RAW files (very useful for high dynamic range scenes where HDR is not an option for some reason) then ISO 100 and 800 are very different.
Forum: Pentax Medium Format 01-06-2012, 08:11 AM  
What happens to the 645D if Kodak goes under?
Posted By procyon
Replies: 11
Views: 2,799
I read somewhere that they sold off their sensors business some months ago.
Forum: Pentax K-r 01-06-2012, 07:00 AM  
why adjust sensitivity?
Posted By procyon
Replies: 31
Views: 2,892
Adam, I think you got that last sentence a bit mixed up.
Forum: Pentax DSLR Discussion 01-06-2012, 04:43 AM  
my most disappointing thing about Pentax
Posted By procyon
Replies: 16
Views: 2,331
Actually I don't understand why DSLR-s don't do focus bracketing. Basically camera would autofocus, do one shot then turn the focus one step in one direction, make another shot then one step to the other direction from the original shot and make the tird shot. Ideally number of shots and step size could be also customized. Focus bracketing btw. allows to make very nice macros if you combine them later. Last time I checked only some compacts modified with hacked firmware allow to do focus bracketing automatically.
Forum: Pentax K-5 01-06-2012, 04:31 AM  
K-5 RAW-image from incamera HDR
Posted By procyon
Replies: 8
Views: 3,777
In-camera HDR jpg has less headroom for post and can have artefacts from moving objects. Single RAW has noise in shadow areas brightened up in post (at base ISO mostly tolerable, but YMMV).
Forum: Photographic Technique 01-06-2012, 04:07 AM  
What to expose for in a sunset/sunrise photo?
Posted By procyon
Replies: 5
Views: 1,655
Choosing to expose for the sunrise is absolutely correct in this case. If ever in doubt always expose for the brightest important part of image. You can always bump up the shadows but clipped highlights are gone forever. Did you shoot in RAW? RAW processors are usually very good in getting nice details out of shadows and not wrecking the brighter parts in the process. Even if you generally don't want/need RAW files I suggest to make an exception in those more difficult cases. Also an option is to shoot an exposure bracket where the darkest image would be something like your current image and then use one of many HDR/exposure fusion programs available(NB! these programs are not only for producing wildly oversaturated and overprocessed looking images, they are also very helpful in getting a nice expossure blended image).
Forum: Pentax K-5 01-04-2012, 04:49 AM  
Screen probs
Posted By procyon
Replies: 18
Views: 1,541
It's a bit hard to understand from your description what exactly malfunctioned?
The title is "Screen probs", but then you say "the viewer died"?
Did something happen on the computer or on the camera?
Were you trying to browse pictures on the camera at the same time you were downloading them to the computer?
That is something I can honestly say I have never even tried to do(but I guess it might be a corner case where things can happen).
I always download pictures by using a card reader as it is much faster.
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