Saturday, September 10, 2016

IC 1318 - The Gammy Cygni Nebula

This large nebula is around the star Gammy Cygni (Sadr) - although Gammy Cygni is actually not part of the nebula but is in the foreground. The nebula lies in the Orion Arm of the Milky Way and is approx. 3000 light years from us.
(click on image for full resolution)

Sunday, September 4, 2016

Should I stay or should I go?

The first two nights at Likely haven't been great at all. Both nights had clouds, the first night I could get at least 2 hours of imaging in. The second night only 30 minutes. And it even rained at the end of the night.

I thought about packing up, but checked all kinds of weather channels:
Android Weather
One says clear now, some clouds from 3pm - 7pm
One says clear all day and night (and it's destintively not clear right now!)
One says clear from 5pm.

??? What to do ???

5:15PM: I decided to stay. And the clouds seem to get thinner!!!

... and it totally paid off: one of the best nights ever!!! Clear skies, no clouds, and pretty much everything went well with the equipment. I could finish my image of IC 1318. The Baby Eagle image needs some more data (lots of noise in the background but also in the nebula itself):

But I took an ultra-wide angle of the Cepheus region with my Polarie:

I should really get my camera modifies - or buy a second without the IR filter. This region has A LOT of nebulosity but you need to look very carefully to see it :-(

Pier collision on zenith imaging

On my first night at Likely Place, I wanted to image IC1318 - which happened to be almost exactly in the zenith at a certain time. I suddenly noticed some crazy guide star movement in PHD2 that could not be corrected. In fact, they got worse and worse. I first though that it had something to do with the backlash issues that I have. But then, the scope did a meridian flip and everything was back to normal.

The next day, I thought to check if the scope maybe hit the pier and couldn't move - and yes, it seems as if there was the chance that the filter wheel hit the control box:

I tried a few things:
  • Moving the control box lower? Didn't work as the guiding cables aren't long enough.
  • Moving the control box to the front (the scope is never anywhere near the front of the pier - but same as before, the RA guiding cable isn't long enough
  • Rotating the pier such that the box is exactly in the back (and thus destroying my polar alignment). Yes, that seemed to work.

Last night, no collisions - yei!

Though it does seem weird that I have to do this exact setup and that I never experienced that before (I'm sure I didn't always have the control box exactly in the back)...

Backlash in both axis!!!

A few days ago, I thought that I parked my scope at the end of the night, but apparently it was still tracking. When I came home that evening, the scope was on the side of the pier - pushing into it!!! Sh### !!! Considering that the scope was upright when I left in the morning, it was probably on that pier for a couple of hours :-(

On the next night of imaging I noticed that suddenly both axis seemed to have backlash: it took PHD2 often several corrections until the scope finally moved. In DEC, it happened whenever the direction changed (afterwards, the corrections worked immediately as the gears were now connected). In RA it mostly happened in one direction (probably when PHD tried to move the scope against the siderail tracking) - it worked in the other direction (the gears were already connected from tracking).

I did the most obvious thing: remesh the gears. I was very careful with the RA gear - wanted to make sure that I didn't switch the gears as I would have needed to redo my PEC. But nothing changed. The next day, I did it again, this time tightening the mesh screws more then normal - still the same effect. I thought that the gears were mainly too tight and loosened them again - no change.

The good news is that the mount tracks REALLY well (especially with PEC on) and that I'm currently using the FLI ML16070 camera which has pretty large pixels resulting in a 1.6 pixel / arcsec scale! So, in most cases, the images are still OK.

I posted on the ap-gto mailing list about this.

Polar Alignment in the middle of nowhere

I like TSX's polar alignment routine (using T-Point) very much: just run 40+ calibrations, get a polar alignment error. Use the Polar Alignment routine (re-center a star) and usually I get a very accurate polar alignment. Furthermore, can do this before it's really dark!!

But when I setup my scope at Likely and polar aligned I was surprised to find that I still had a noticeable polar alignment error (judging by the PHD2 guiding graph that showed the DEC axis drifting). I made sure that I entered the right coordinates (lattitude, longitude, elevation). But still the same. The polar alignment routine worked without any problems though.

... and the next day it dawned on me! The computer on the scope does not have an internet connection (the wireless signal in the area where you setup your scope at Likely is very weak). Which means that Dimension4 can't synchronize the clock on the computer! And when I compared the times between the scope computer and my laptop (which I took up to the club house and connected it there) I could see that they were not in sync :-(

After having used the TSX polar alignment so long, I am not sure how accurate my RAPAS still is. So, I used Alignmaster. I'm pretty sure that it doesn't require an exact timing as it only measure the error when slewing from one star to another. I did that and the alignment error was MUCH smaller (though still not completely gone - but it could be guided out and didn't cause any visible image rotation).

Not-so-flat-sky Sky Flats

On my first night at Likely Place, I tried to take sky flats, but unfortunately, the sky wasn't clear but some clouds were in it (which disappeared later on). Second evening looked the same. And then I remembered Richard Crisp's way of doing sky flats. He does them during the day. Puts several layers of white cloth (clean T-shirts) over the scope and covers the back with aluminum foil to cover any light leaks.

Well, the T-shirt idea sure became handy:

The flats turned out great! The T-shirt also helped with the Luminosity flats who often get some stars into them as they have to be taken very late.

... though the rest of the night sucked: many, many clouds and in the morning it even started to rain lightly (before I could cover the scope!!!)

Saturday, September 3, 2016

Installing TopazDenoise on Photoshop CC 2015.5

For the Milky Way images, I wanted to re-install the TopazDenoise filter (I used them before on a different laptop but didn't install them on this one).

I downloaded them again and installed them. But when I opened up Photoshop, they weren't there. I restarted Photoshop, then all Adobe apps (Lightroom, CC Update...) and finally the laptop. But no luck.

I checked in my filesystem and under C:/Program Files/Adobe/Adobe Photoshop CC 2015/Plug-ins, I found a link to the Topaz plugin.

Then I searched on the Topaz web site and found instructions how to install the plugin manually on Photoshop 2015.5 (copy the plugin to C:/Program Files/Common Files/Adobe/Plug-ins). Tried that, restarted everything - still no luck.

Searched on my disk again and found another Plug-ins folder under C:/Program Files/Adobe/Adobe Photoshop CC 2015.5/Plug-ins. Copied the plugin there. Restarted and: voila!

... who in his right mind came up with the Photoshop version 2015.5 ???!!

Friday, September 2, 2016

5th Night: Around Crater Lake

Weather conditions did not change much. So, we decided to stay at Crater Lake but now take photos in the surroundings. First, we took sunset images of Mt. Thielsen from the Pumice Desert outside of the Crater (yikes, this will be a pain to clean up those optics!)

Then we went to a nearby, small lake and took Milky Way images from there. The small lake and the trees made a great composition:

And when clouds moved in, I took a short timelapse of the Milky Way behind the clouds (forgetting once again that vertical is a bad movie format!!!)

And then we had to say goodbye!! I can't believe how quickly the week went by and how much I learned, the great people that I met and the awesome photos that I took!!!

Continue on: Should I stay or should I go?

Thursday, September 1, 2016

Processing Star Trails

We had our second processing session with Dave. This time we focused on Star Trails. Dave also has an excellent YouTube video about this!
  1. First, load all images into Lightroom
  2. Pick one image to work on.
  3. Adjust White Balance
  4. Increase contrast (to get the star trails out well): move histogram to the right and black point to the right.
  5. Adjust exposure
  6. Increase Whites (brighten stars)
  7. Don't touch blacks - or even lower it to make sky darker.
  8. Now do the same as for the Milky Way shots.
  9. Go back to Library view
  10. Select image, right click, select "Developer Settings" -> "Copy Settings" -> "Select all" -> "Copy"
  11. Then select all images and click "Sync All" - now all settings from the first image are applied to all other images.
  12. Now, right click (all images still selected!) and export to JPG (PSD or TIFF would require A LOT of memory as all images have to be loaded at the same time into Photoshop)
  13. Open Adobe Bridge
  14. Select all images
  15. Load in Photoshop as layers
Now, Photoshop opens with all those images as layers (might take a while!)
  1. Pick a file that has a good foreground (no light pollution, some details...)
  2. Rename it to "Base Layer" and move to bottom of the stack
  3. Select all other Layers
  4. Group them together (name "Star Trails or so)
  5. Change Blend Mode for all images to "Lighten" (this picks the brightest pixel of each image for the result making all star trails come out - but it also picks up all of the light pollution and plane streaks :-(
  6. Temporarily move the group down
  7. Add a layer mask to the "Base Layer" image
  8. Add a lot of contrast (make foreground black and sky VERY bright) by moving midtones to the left and black point to the right)
  9. Use Dave's Actions
  10. Remove this layer and move Star trails back to the top
  11. Now select a channel where the foreground is white and the rest is black
  12. Add it as a layer mask to the Star Trails group and paint into it to reveal the foreground from the Base Layer image
  13. Now cleanup plane trails with the Stamp tool (Dave did it on the entire image, I found it easier to do on each individual image - though it takes A LONG time!)
  14. Now delete all channels and run Actions again - now we have the real channels for our image
  15. And now process the image similar to the Milky Way image:
    1. Pick an area / objects to modify (e.g. make stars brighter)
    2. Select mask where area / objects are white
    3. Pick Adjustment
    4. Make adjustment
    5. Create Group
    6. Add Layer Mask and reveal/hide the area
  16. And at the very end remove noise from the foreground as before.

4th Night: Crater Lake take two

Pretty much all of Washington and Oregon was under clouds - except Crater Lake. So we stayed another night and took images from the west rim. But first, I spend the day driving around the lake, stopping here and there and taking images of the beautiful area.
Crater Lake with Wizard Island
Phantom Ship in Crater Lake
East Rim of Crater Lake with Pumice Castle
Devil's Backbone

First, we were treated (again) to a five start sunset (thanks to wildfires!!!) And again: this is just a small selection of all the beautiful images that I took.

Then we stayed there and took Milky Way images. Unfortunately it got very cloudy and VERY windy and cold. We spent most of our time in the cars and only hopped out when the sky cleared up.

I took another Milky Way image:

and a star trail:
Startrails over Crater Lake
I then stayed in that spot and set my alarm clock to 2am to take another sunrise timelapse. But when I got up at 2, I couldn't even see the lake - we were completely fogged in! Out of desperation I set my alarm clock to 4am - and when I woke up the sky was completely clear!!! And it was soooooooooooo cold! Initially I wanted to setup my slider and everything. But I just put my camera on the tripod, connected it to the tablet and intervallometer, started everything and hopped back into the car.
An amazing result!!!!! (though I wished I had let the camera run for a little bit longer until the sun is completely in the crater):

Continue on 5th night: around Crater Lake (or if you are interested: Processing Star Trails)