Astrofriend

I remote control the shutter through bulb mode, the most sofware don't accept shorter then 1 second. And the time precission isn't very great with too short exposure in bulb mode. Shorter exposures can also make interference with the power control of the light source. /Lars

Hi, I have tried to use filter to filter a light source that didn't have the correct color balance, it works but the light source was weak and I got long exposure time. Now when I can adjust the light source color temp direct I have much better control over the process and the light LED strip is powerful too. In my test I have relative low vignetting optics because I use a medium format lens together with my full frame Canond 6D. The curves on the histogram is narrow, with high vignetting optics they are much wider. Then it's even morre important to have each color in the middle of the histogram. Many cameras compress the signal at higher level then the signal must be even lower. I have no experience of modified cameras, but the problem is the same, flat image get better with all three colors in balance (same level). I normally take 60 images and stack together and subtract the dark flat, the dark flat I do simple, use a bias because of the short exposure when taking flats. Sometimes I replace it with a constant, 2048 in the case of Canon 6D. The examples in the graphs are raw CFA levels and linear. Of my tools the Fitswork is best to do this analyze. First calibrate, then debyer, but to get the histogram with each color separate I have debayered it (because its difficult to explain otherwise). Can do direct on the CFA but then the levels are little bit difficukt to analyse, but that is what I normally do because the debyer proces can mess with the levels. Remember, there twice as much green pixels compare to the red and blue. /Lars

Just a few days before Christmas, today I felt it was a good day to do something about my flat images. It has always been a problem. With color cameras there is a need to have the three color channels at the same signal level as the camera sensor see it. If not it can be that one color channel oversaturate and another one get too low and get noisy. I have used a monitor where I can adjust the color and other stuff, no one was easy to use. Now I building one with a RGB LED stripe with some extra control of the colors. Interesting ? You have photos and text about my DIY here: http://www.astrofriend.eu/astronomy/tutorials/tutorial-flatcalibration/07-tutorial-flatcalibration.html This is the one that worked best yet. But I have to develope it more now when I know I can use it. The 3D-printer will come in use again. Merry Chrstmas to all of you ! /Lars

Hi, We have just arrived home after our travel to Fuerteventura at Canary Islands. It was a tourist trip but we always try to add something about astronomy. We have read about Fuerteventura's dark places, areas that are protected against light pollution. We visited one, the Sicasumbre astro viewpoint during daytime as an orientation. Here I share my photos from this tour with text and links: http://www.astrofriend.eu/astronomy/observatory-sites/fuerteventura-astronomy-park/fuerteventura-astronomy-park.html One problem, it was very strong winds, it was like to be inside a sand blastering machine. Enjoy the reading ! /Lars

A second version of the design of the focus chassi, now with a flex joint to act as a hinge instead of the earlier sliding roller bearings. http://www.astrofriend.eu/astronomy/projects/project-focus-friction/page10-project-focus-friction.html /Lars

I continue with my attempt to build a 3D-printed 3" focuser. I have now made the CADs for the rack & pinion gears, started with the worm gear, make the focus shaft holder and the focus chassi. Lot of details left to solve. Here is my document, see page 7 to 9: http://www.astrofriend.eu/astronomy/projects/project-focus-friction/page07-project-focus-friction.html Maybe it will not work with enough precision, but it's exiting to do at least a prototype. I can always hand over the CADs to someone who has a metal 3D-printer. /Lars

Today I did some more work on my implemention of a rack & pionen gear into the friction type focuser. I took apart the focuser and did some measurement how much space I have and what parts I can reuse. It's very limited space and will be difficult, but not impossible. Here is what I did: http://www.astrofriend.eu/astronomy/projects/project-focus-friction/page08-project-focus-friction.html /Lars

Hi, That looks very good, maybe a much better wedge than the original wedge. Thanks for posting ! /Lars

In these rainy days I thought a lot about my focuser. The original friction focuser which is very good when only attaching low weight oculars but doesn't work very good with heavy loads as a camera. It will never work as good as I wanted it to do whatever I try to do with it. Now I try to rebuild it with a rack & pinion construction, and more, I try to 3D-print the parts. Have a look on my first prototype gears: http://www.astrofriend.eu/astronomy/projects/project-focus-friction/page07-project-focus-friction.html This is very exiting if I can use the 3D-Printer to make this rack & pinion mechanics. The 3D-Printer is my best friend ! /Lars

I have looked at these geared heads too but never tested them. Have you tested them and got some interesting results ? /Lars

My EQ6 projects continue forever. I had a lot of problems with the hardware driver in the EQ6 mount. There is some bug in the driver I had understand, that's why there is a RA drift compensation in EQMOD. With my custom gear ratio this problem got worse. Now I decided to replace the original driver with an external driver. I already have an AstroEQ driver that I want to test. I need some space where to place it, I have here started 3D-print a new lid for the EQ6 mount: http://www.astrofriend.eu/astronomy/projects/project-eq6-dismantling-rebuilding/20-eq6-dismantling-rebuilding.html I have also ordered some connectors and cables to make adaptercables between the RJ11 6/4 to the JST connector that the stepper motors have. /Lars

It's the end of the astro season for us in Sweden, I maneged to take a last photo with my new setup with the Pentax 645 300 mm lens. That was good for me, I need motivation. I have struggled with this new system over 5 years, most problem with the Raspberry to get it to controll it. This is the first astroimage with the new setup, are you curoius of how an 35 year old lens catch the stars ? Very light polluted environment from my balcony, Bortle 9, but look at the shape of the stars at the corners of the full size photo, it's a full frame camera sensor. http://www.astrofriend.eu/astronomy/astronomy-photo/open-clusters/m39/m39-open-cluster.html Next thing to get to work is the dithering process, that will eliminate the hot pixels you see in the background. And then a suited battery and I can take it out to dark places, but that will not be until the next winter season. I want to keep it below 25 kg included the HEQ5, lenses, computers and a battery that can handle 10+ hours. /Lars

That must be very exiting to show the youngs. We have a big planetarium here in Stockholm, Cormonova. It was a couple years since last time we visited it, my girlfriend wnet seasick 🙂 /Lars

Yesterday I got a massive help from my friend. It was the stup of GPS unit for the Raspberry which has caused me problem the last 5 years. Now we got the GPSD driver to work direct with a GPS dongle: http://www.astrofriend.eu/astronomy/projects/project-heq5/07-heq5.html And the GPS NMEA where the Raspberry get the clock and position from a smartphone: http://www.astrofriend.eu/astronomy/projects/project-heq5/08-heq5.html Very glad to have solved these problems. Next step is to install KSTars on an Android pad. My own was to old to install the software on. /Lars

Hi Bish, Glad to hear you find some interesting. What kind of project do you do in the astronomy area ? ps. Nice with cars in the summer with no dark skies. /Lars

Maybe you have got problem as I did with the temperature regulation of the 3D-printer. In my case I got this problem when I changed from PLA to ABS pro filament. When I set the nozzle temperature to what's needed for ABS it didn't stabilize enough. It oschilated around the set temperature and the 3D-printer refused to start printing. It was the P.I.D. parameters that was wrong. After some research I found how to solve this problem. I have write it down how I did it. Maybe interesting for other users of 3D-printers. http://www.astrofriend.eu/3d-printing/3d-printer-setup/15-3d-printer-setup.html /Lars

I know from my friend who live in Uppsala, the 19th instruments are still in place in the main building. One of them is the exiting double refractor. /Lars

This is a follow up to the article "Old Swedish observatories" I translated not long time ago. We made a visit to Uppsala old observatory which is placed in a beautiful park almost in center of Uppsala in Sweden. I took some photos from the visit and have tried to find some information to it: http://www.astrofriend.eu/astronomy/observatory-sites/uppsala-old-observatory/01-uppsala-old-observatory.html /Lars

Hi Steve, Yes, Ekos and KStars. I have a lot of problem with this earlier, but now with the new Astroberry version 2.0.3 everything worked after an update. I use this because it takes much less space and don't need very much power to run, important when on battery with a portable equipment. This is what I did one year ago, never got it to work: http://www.astrofriend.eu/astronomy/projects/project-kstars-raspberrypi4/01-project-kstars-raspberrypi4.html Now when it works and if it's stable I can replace my other setup which is Windows based with a similar controller. Windows get more an more complicated to use, all these updates gets me crazy and all problem with drivers. But the functions in the astro software I think is still better. Do you have any experience of Ekos ? /Lars

Last night I could do my first test with a Raspberry controlled HEQ5 mount. Worked much better now compare with all problem I had one year ago. I succeeded to: Plate solve, auto focus, take images. What's left to fix, auto guiding, GPS module to communicate. Tonight it looks to be a clear night too. I will do a new test run, concentrate me on the auto guider, now in the beginning I use the internal guider, later maybe I change over to PHD2. Very exiting. My setup of HEQ5 and a 300 mm Pentax 645 lens: http://www.astrofriend.eu/astronomy/projects/project-heq5/01-heq5.html /Lars

If you have a EQ6 mount as I do you maybe noticed that the bottom of it is not flat. If you want to install it on a pier you must have something between the EQ6 mount and the pier. I started with one made of wood and planned to replace it with one made of aluminum. But now when I have a 3D-printer, can it be made of plastic and still be stiff enough ? Curious as I'm I have to do a test: http://www.astrofriend.eu/3d-printing/eq6-pad/01-eq6-pad.html Still printing. Lars

Today I came in contact with a person that maybe can let me into the observatory building. Lars

A couples of days ago I fixed the tilt of the camera that I had. The tilt is caused of the bayonet of the adapter isn't tight enough. I thought about a lot of different solutions including a new 3D-printed adapter. But after a while I choose a very simple solution, a string and a spring that force the camera to be in correct angle and position. Have a look at my photos from my Pentax 645 project: http://www.astrofriend.eu/astronomy/projects/project-pentax645-300ed/04-pentax645-300ed.html When the camera is out of focus the shape of the stars look very strange, but when in focus okay, all the way out to the corner. But must get the auto focus function to work better and calibrate the temperature compensation to get it perfect. In the future I will 3D-print my own adapter and include some more funtions into it. Lars

Today I anlyzed my flats that I have taken with my Pentax 645 300 mm lens, they are takne at full aperture, f/4. As I expected the vignetting is very low, much lpwer compare to my Canon 300 mm L lens. That was one of the goals. Of course I want it to be a sharp lens too. It looks okay but at one corner the stars are a bit elongated, it must come partly because of a tilt of the camera house. The bayonette adapter doesn't fit very well and cause this. This how the vignetting looks: http://www.astrofriend.eu/astronomy/projects/project-different-lenses-vignetting/06-different-lenses-vignetting.html /Lars

One more clear night and I could do more test of my new setup. This night I tested to autofocus the lens. First I used APT which I downloaded the latest Betaversion of. In the Beta version is a more advanced autofocus function implemented. I got it to work, but there are things that need more development. I installed N.I.N.A. which also have an autofocus function, it worked pretty good and I could setup the focus motor's backlash compensation correctly. Some screendumps and explanation text of what I did: http://www.astrofriend.eu/astronomy/projects/project-pentax645-300ed/01-pentax645-300ed.html /Lars