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Forum: Pentax K-5 & K-5 II
04-05-2018, 01:17 PM
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Thanks a lot for the clarification.
I followed the development of KStars and Ekos via the Indi.org portal and helped debugging for a year or two. In the meantime I got familiar with what Indi has to offer. I deployed it on a few RPi machines, powered all with a normal and cheap car battery and managed to be autonomous for at least a night. I added a Zwo astrocamera and used it for guiding and now and then for taking series of light frames to be stacked initially with the Win based Deep Sky Stacker and started looking for a full Linux solution. On my bucket list I needed still the tethering of my Pentax K-5 and the familiarization with the professional IRAF for image processing. With the progress in the field of the K-5 one action on my list can be deleted. In order to be totally autonomous in the field far away from internet and the possibility to use the NTP time synchronized service I have still a GPS module in my drawer to be used with and older RPi and configured as stratum 1 time service.
Step by step I am progressing but this step is a big one.
This evening connected my K-5 with my desktop Pc and I saw a completely different behavior than I am used to. It is not yet 100% operational but this is a question of configuring the system.
Stefan
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Forum: Pentax K-5 & K-5 II
04-04-2018, 09:52 PM
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Hi Gbeaton,
I checked the Stellarmate site and understood that it is now a complete system based on a RPi3 with Linux OS (probably KUbuntu) and a series of tools (probably including VNC, SSH, and of course the Indi suite).
From there I deduce that today the Pentax K-5 has now a proper Indi driver allowing direct control from KStars and Ekos. Could you please confirm this and that no other middleware needs to be installed?
The K-5 needs to be put on Misc for the USB config, isn’t it?
Best regards and thanks in advance for the confirmation.
Stefan
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Forum: Pentax K-5 & K-5 II
03-30-2018, 03:00 AM
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That is great news. I must recognize that the last year I was not active at all in the field (moved from Belgium to Italy for work). I will try this out immediately and report back. Excellent and thanks a lot for sharing the information.
Regards,
Stefan
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Forum: Pentax K-5 & K-5 II
03-28-2018, 02:02 PM
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Thanks for your reply. Are you saying that today K5 can be controlled by KStars? This is new to me as a year ago I did not succeed. After having discovered entangle that is based on gphoto I wondered already whether KStars would also work now. Do you know who moved to who? Did Pentax finaly made their equipment compatible with the standard or was it vice versa? As long as it works and it is stable we should not bother. I will try KStars again. Regards, stefan
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Forum: Pentax K-5 & K-5 II
03-27-2018, 05:08 AM
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Hi,
It is now a couple of years that I was looking for tethering software for my K-5. I even contacted Pentax directly but without result.
Just yesterday I looked again on the Linux fora for solution and I could not believe my eyes. Since last October 2017 the first version of ENTANGLE was released. Totally free and open source!!!
I immediately installed it and after a few minutes trying different camera settings I got it working.
FANTASTIC!!!
The tool allows also a command line interface. You can control a limited number of Camera parameters and the pictures end on your PC hard-disc without problems. So far I found it very stable.
:)
I am curious to read your experiences with the tool and will report back about my findings.
Regards
Stefan
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Forum: Pentax K-5 & K-5 II
01-09-2017, 12:51 AM
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Hi,
I succeeded reading and interpreting the DNG header. Next I will extract the image from it. That's the interesting part. Once I have the image byte per byte stored in a 3d array, the real work begins on the images.
With the header info it will already be possible to do some quality checking between my observation journal (settings of the camera, time and date etc.) to be enriched with platesolving and storing all the info in what will become the FITS header.
Stefan
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Forum: Pentax K-5 & K-5 II
01-06-2017, 06:55 AM
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Dear Pete,
I happy to see that you confirm my initial expectation! Indeed, noise should be very low with these settings.
I do not see problems in pictures I took, and that makes me think there is a problem with the data import in Python or my interpretation of data in Python is wrong.
This evening I will try to reproduce the data sequence with ImageJ and report back.
Thanks a lot for your reply!
Stefan
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Forum: Pentax K-5 & K-5 II
01-05-2017, 04:48 PM
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Sorry Pete, I tried again and it should work now.
Regards,
Stefan
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Forum: Pentax K-5 & K-5 II
01-05-2017, 02:46 PM
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Trying to get some grip on image processing, I started with taking 50 frames with my Pentax K-5. The settings are as follows:
- Manual setting
- ISO100
- Exposure 1/8000s
- Cap on viewfinder and lens.
- K-5 completely in the dark at 22°C
- Frame format DNG
- Interval between frames is 10sec.
- All noise processing, filtering, correction performed by the K-5 were switched off.
These are the conditions for shooting BIAS frames as far as I understand.
The frames are imported in Python using rawpy (the DCraw modules allowing to read and interpret DNG frames).
The frames are uploaded in rgb 16 bit format what gives me an array with the rgb channels.
I took at random one pixel somewhere in the middle of the frame and compared the channel intensities for all frames in the sequence.
Bias frames show the error of the zero value measured by the 14bit ADC of the K-5, and I expect that this error values is rather stable and small.
To my big surprise I obtain the following result:
The same pixel (pixel [1500, 1500]) has fluctuating values of the channel intensities with up to 25% of the maximum value that can be represented between the different frames taken.
For me this is huge and probably something went wrong in the reading of the frames. If I divide the rgb16 array in Python by 256, I get an 8bit representation of the frame that can be visualized.
With light frames made with the same camera and stored in a DNG file, my Python procedure allows me to see the 8bit picture in the real colors.
My question to the forum is, whether this fluctuation of the pixel rgb values from frame to frame is normal and to be expected?
Thanks in advance,
Stefan
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Forum: Pentax K-5 & K-5 II
09-11-2016, 12:30 PM
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Thanks a lot for the advice.
Stone G. I was trying out pkTriggerCord on a linux box, and yes it works but easily blocks the whole camera in a way you need to take out the battery or it does not want to restart. I thought that pkTriggerCord was the more recent version of pkTheter. For you pkTheter works without blocking??? I am immediately going to try this out and keep you informed.
oneeyedhawk, my setup is mobile and car-battery powered. I do not want to add a 12V-220V converter and therefore I use now a Samsung tablet wifi connected to my telescope gear. Samsung sells a micro-usb -> HDMI converter and I took the MHL 3 version. This version seems to allow HDMI in both directions, hoping that my K-5 could work as source and my tablet as screen. Unfortunately this idea does not work out.
Many of my colleagues use now Bahtinov screens to focus, and that seems to work fine, but they watch their pictures on a PC monitor screen.
---------- Post added 09-11-16 at 08:39 PM ----------
Sone G. I just saw why I did not tried before with pkTether, it seems not to be available for linux.
Same problem with other good-working tools under Windows. I am using linux because it runs on a credit card size quad-core machine. Unfortunately these machines do not run windows.
I have never thought to use the Pentax low-light autofocus. Will try this out during the next cloudyless night. My refernce star is Vega, so this should work well.
Thanks again for the excellent hints.
Stefan
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Forum: Pentax K-5 & K-5 II
09-11-2016, 06:08 AM
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Hi,
When I see these excellent pictures made with a K-5 I wonder how you get it so well in focus.
I have now a setup with a mount, a telescope and a dedicated astro-camera mainly for guiding.
With the KStars application under Linux on a very small Raspberry Pi 2, I am able to focus the astro-cam.
The main tool is the viewer of the pictures taken together with the focussing module of EKOS (part of KStars).
When guiding, I take pictures with my K-5 mounted on my guiderscope.
Pentax does not provide software to at least download a picture to a PC on which you can zoom and run a protocol for focussing.
The Pentax LV screen cannot be rotated in a position that you can easyly adjust focus (k-5 is mounted high on telescope).
I use a 90degree prisma to look through the viewfinder, but you can hardly see even the brightest star to focus on.
My colleagues of the observatory all use Canon or Nikon with software such as BackYardEOS, and they focus the camera on the PC with very good results.
I get hopeless when suffering with this K-5, unless someone could explain the method used.
I am seriously thinking about selling my K-5 for a Canon, knowing that I will not get better quality for a higher price.
Does someone have some hints? If I could get the pics already via usb on my computer for checking that would already be something.
Thanks in advance!!!
Stefan
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Forum: Pentax K-5 & K-5 II
02-23-2014, 01:23 PM
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I am not able to get PK_Tether running on my XP box. I installed .NET 3.4 and 4 but when it starts it generates an error report to be sent to Microsoft and than quits.
I wil have a look to the source files. They must contain all the details about how to connect to the camera and which functions exist.
St
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Forum: Pentax K-5 & K-5 II
02-22-2014, 10:19 AM
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Hi Stone G.
Yes I am working with it right now.
It still has some small things that can be improved but it is really what I need.
Important to mention is that the tool hangs after the third picture taken with automatic delete and save. This is probably due to the fact that some small previews are presented and there is only place for 3 in the window.
This evening I am going to calibrate the focussing of my samyang. I have now a robust mounting of my K-5, a x2 tele-converter and the 800mm samyang.
Finding the focus of the set up is still difficult. Now that I have the camera connected to the PC, I can take pictures and directly analyse them with AstroImageJ or just ImageJ. I hope it will work.
Regards,
Stefan
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Forum: Pentax K-5 & K-5 II
02-22-2014, 09:58 AM
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Hello Forum,
After some experimenting with my Pentax K-5 I was looking for remote control from a PC.
A few days ago I discovered a fantastic open-source tool called kpTriggerCord.:)
It allows to remote control the K-5 but also other Pentax camera's via the USB port. The tool requires GTK2 and is available for Windows, Mac and Linux.
I only tried the Windows version and yes it works.
The GUI in this tool allows changing some parameter values and taking pictures.
Does someone have experience with this tool?
Are there programmers around knowing how to connect to other functions in the Camera? Reference documentation for the API etc?
From the tool web-site pkTriggerCord I learned that with the command line a lot more parameters can be controlled.
Stefan
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Forum: Pentax K-5 & K-5 II
09-08-2012, 02:29 AM
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Dear Members,
DSLRs make people dream. Finally one could focus on the life view screen and even zoom electronically before focussing. Is this theory?
I posted a few days ago a question about lens focussing on the night sky (zooming in 32x on star pictures start showing coma and focus quality). For astrophoto's one would put the lens focussing on infinity and forum members explained that the infinite setting on the lens takes also a margin for thermal dilatation. I tried to focus manually around the infinity mark but this is not very easy via the viewfinder. If one could use the life view function this would be fantastic, but stars are so faint that there seems to be not sufficient light to show the star image on the life view screen. is there a solution for this?
Using life view is heating up the sensor (constant pumping image data to the processor) and will increase the noise in the image. The K-5 seems to be the best performing DSLR on the market in its category as far as low noise is concerned (the amplifier from Pentax seems to be much better compared to the competitors using the same sensor) and this is the reason why I bought the K-5 for astro-purposes.
Regards,
Stefan
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Forum: Pentax K-5 & K-5 II
09-08-2012, 02:08 AM
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Hello,
Does this mean that it is impossible to combine the use of the interval timer of the k-5 together with the Mirror up function?
I could not find out whether really the mirror was locked up before starting using the interval timer.
For astrohpoto's the interval timer (function allowing to select how many pictures are taken and with which time distance) is interesting so that the pictures can be stacked. In order to reduce vibrations to the minimum, I would first make sure that the mirror is locked up. For that I use the MUP function. When activating the multi picture mode (interval timer) in MUP mode and starting the process I hear the mirror (at least this is what I think it is) swapping up (or is this only the shutter?). I expect that with MUP my K-5 start behaving as a mirror less camera. Is this really the way it works?
Regards,
Stefan
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Forum: Pentax K-5 & K-5 II
09-02-2012, 01:32 PM
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Here is one of them.
After checking the property fields I see now it is using an 18mm F/3.5 20sec. The bright stars out of the centre have strange forms when zoomed.
A second picture is made with an old 50mm F/2 10sec. Here the strange forms can be seen even better and especially outside the centre of the picture. Is this astigmatism?
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Forum: Pentax K-5 & K-5 II
09-02-2012, 09:12 AM
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Thanks for the suggestion about over-infinity for thermal expansion. It is probably that what causes the problem. I always used the timer for exactly that reason. There was no wind and no traffic nearby, so vibrations from cars etc. are probably not at the origin of my problem.
As I stated before, I tried yesterday evening the full moon and it was again blurred. Changing the exposure time does not change anything, so if it is about vibration a 1/500s exposure time should be rather OK and it isn't.
If there is an open sky tonight I will try again with special attention for the focus. I will also try to use the MUP in order to avoid even mirror vibration. I'll keep you posted!!!
Regards,
Stefan
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Forum: Pentax K-5 & K-5 II
09-02-2012, 08:48 AM
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The f stop was 4 with focal length 50mm.
I tried yesterday also the full moon and it was rather blurred. This time with focal length 200mm and f=5.6. Exposure time was up to 1/500s but increasing the exposure does not result in sharper images.
Stefan
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Forum: Pentax K-5 & K-5 II
09-01-2012, 03:10 PM
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Dear Forum members,
I just bought a K-5 and tried it out on the Belgian (not so dark) summer night sky.
After zooming the raw picture on the camera up to 32x I was surprised to see that the stars did not show up as dots or segments of a circle but
as strange forms (as the picture was not really sharp but the lens was put on infinity).
The tripod I used was not the most robust one, and the lens is a standard Pentax 50-200mm that came with the camera.
What is going wrong here? The tripod? The lens? The mirror flapping up and down and creating vibrations?
Thanks a lot in advance for the help and suggestions.
Best regards,
Stefan
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