i've been living here on the top floor of a three-story building right outside of boston for
the past few years and one thing i've noticed is that from this wooden deck which i'm on right now
it's south facing and i have a really good view of the planets when they're up and setting in the
early part of the night and i've often just you know taken a quick look at jupiter's moons through
binoculars but for some reason it's never occurred to me to bring out my 10 inch dobsonian telescope
which is right here well the other day i changed that and i have to admit it it was
sort of frustrating because due to this being an old wooden deck on the third floor if i just
moved a muscle the whole view through the eyepiece was violently shaking for several seconds before
calming down and that's because when you're very magnified like you would be with a big
telescope and an eyepiece any small vibration or movement will have a huge impact on the view but
with enough practice it's saying like super still and just uh you know just really taking my time
i i did get it to work and i observed the planets visually for about 10 minutes before i really
wanted to try to photograph them and i have a bunch of different cameras i could have used
and in some ways the best would have been one of those like small sensor guide cams or planetary
cameras from qhy or zwo and i have some of those they capture frames very quickly uh
they can do high frame rate because they go right to the computer and they're using a small sensor
but keep in mind this telescope has no motors uh it's it's i had to manually recenter the planets
to get them onto the camera sensor and then the planet will leave the camera sensor just after
a couple seconds so i'm really trying to do just very short bursts of video and so for this i think
the dslr is a better choice i have this old canon dslr the 60d that has a very interesting set of
video modes including one that crops into just 640 by 480 pixels into the center of the sensor
in a one to one crop mode and that's ideal for planetary since it should give us much
sharper results with fewer artifacts than a normal video mode which is taking the whole sensor area
and compressing it down to a standard hd or 4k frame size but i didn't want to start in that
special crop mode because then i would have had the exact same problem of using like a small qhy
or zwo sensor instead i get the planet all framed up and centered in one of the other video modes
it's using the whole sensor and this way it's much easier to find the planet and then i just try to
quickly switch to the crop mode and record a very short video before the planet leaves the frame
now doing that while also not shaking anything was really really challenging and so you can see many
of my attempts here did not really work out so well but i did have a few attempts where i think
i got something usable um well at least considering how janky this whole setup was
if we can get any surface detail on the planets after stacking i'll call
this whole experiment a success and i should mention this telescope is the skywatcher 250p
flex tube collapsible dobsonian you've probably seen it in the background of most of my videos
it has a focal length of 1200 millimeters a focal ratio of f 4.7 but i was using a two and a half
times barlow lens attached to my dslr with a t adapter here and so that puts me at an effective
focal length of something like three thousand millimeters at f12 i do have to admit that i
forgot to collimate the telescope uh which shows you how rusty i am at using reflectors um but this
is just for fun it's just a test run to see how well this works so i'm not expecting too much
but the last part of this video i'll show you how we take these short videos that i made on the dslr
and process them with free windows software to make a usable final image okay i've transferred
uh the best movie that i could find of jupiter and of saturn onto my computer here and then i'm
just going to drag it into pip which is stands for planetary imaging preprocessor and i'm just going
to make this really simple i'm just going to click on optimize options for planetary right here on
the first page and then that turns on a bunch of stuff that i want for pre-processing a planetary
movie like this so it's going to center object in each frame of the video which is something that i
want to do it's going to do auto object detection if i test this you can see there it's finding
jupiter um even though it's sort of out of frame in that first frame and if we want we can turn on
enable quality estimation we can also of course do this in auto stacker which we're going to be
using next if you do do it here i would keep it at a pretty high percentage of frames kept
at this point and then we can bring that down further in auto stacker in output options i'm
just going to select a directory i'll just make a new folder on the desktop for this call it jupiter
and then i'll just click on do processing and then click start processing
okay and if i look in this folder now get rid of this here is the original image
and here is the video after pip has centered it
okay and we're going to turn that into something much better
but we have to first stack all of those frames to make it into one
image so we're going to do that with auto stackert here we go so i'll just open up
the image that we made with pip and make sure that it says planet right there and then i'm going to
you can manually draw control points onto here or alignment points i mean
but i'm just going to use the place alignment point grid option and then click analyze
okay and then it estimates the the quality of all the different frames i usually have mine
set up like this we're gonna create a tiff we're going to um do different stacks for 30 40 50 of
the total frames turn on rgb align i'm not going to use drizzle and then i'm going to click stack
okay that's now done i'm going to x out of auto stacker and open up registax and
in here i'm just going to click the select button go back into my jupiter folder
and now there's these three new folders from auto stacker let's try the 50 one
okay so that's out of
auto stacker just the stacked jupiter and it looks a lot um you know smoother and less noisy than the
video but now what we're going to do with this very smooth out stacked image is add wavelet's
processing so i'm going to change the wavelet's scheme to dyadic from linear so we have dyadic
gaussian and then i'm going to start turning up these wavelet layers right here
and what i'm trying to do is we're gonna i mean you can obviously see if i just turn this
off and on
that last one was most dramatic it looks like the uh the level three wavelets uh
is where a lot of the detail is in this shot
i don't know if i like what level four is doing so i'm going to turn that down a little bit
you can see that
if i try to add level 5 that's going to add a lot of ringing
i might just turn level five and six off
okay um and then the other thing other than wavelets that i like to do in registax is if
you see any kind of we already did rgb align in auto stacker but they also have it in here
if you see any kind of issues there you can mess around with the red and blue channels
i'm going to a little bit of denoising and de-ringing okay and now i'm going to click
this do all to do all of the processing that we just set and then i'll click save image and save
this off as a tiff file okay and then i'm going to repeat that same exact process for saturn
okay and then i just uh brought the two photos into photoshop and put them together to show the
relative size of the two planets and just to did a little subtle curves and saturation um but that's
it um so pretty straightforward i you know you probably could do a lot more with better data but
this is just a sort of brief introduction to planetary imaging i'm still learning myself
and this was just sort of a practice run for me on the deck so hope you
enjoyed this one until next time it's been nico carver nebulaphotos.com clear skies