When doing visual observing at a telescope, I find myself wishing I could record the image. I know some people sketch but sketching isn’t for me. Astrophotography with a connected DSLR or dedicated camera is great but that isn’t visual observing. So, I have been very interested in the concept of afocal astrophotography. I earlier got an adapter for an old point-and-shot camera but was a lot of work to get the camera positioned and then figure out all the controls. Again, I could use the DSLR. But, then I found an article about using a smartphone. So, I purchased a couple of adapters which sat gathering dust. But, going to make it a goal to figure out afocal photography using a smartphone.
I first step was to do some researching on the Internet. A number of article I found are below. Here are my takeaways:
- Smartphones can take adequate images through the eyepieces. This is partial due to the increasing technology in each new smartphone model.
- An adapter is necessary to hold the smartphone steady over the eyepiece.
- Something is necessary to take the picture to avoid movement
- Dedicated apps will probably help with the process but curious how the native camera controls do.
The next step will be to re-review the two adapters I have.
Tagged: afocal, smartphone
I took some images using my ZWO ASI034MC and Meade ETX90EC. I used SharpCap to capture of still images and a couple of videos. I reviewed the results and something didn’t look right. The images of the moon were very low resolution and had a grid pattern over them. The images of Saturn and Mars showed no color. I am sure I saw some red for Mars. I checked the Camera Settings view and noticed the Color Space was RAW8. I thought I had changed this but out of patience using SharpCap since the last time was the solar eclipse last year.
I did some research and found this article https://docs.sharpcap.co.uk/2.9/10_CameraBasics.htm. It explains what the differences are for the color spaces in SharpCap. I guess it makes since that I captured a RAW format. I have been capturing images in RAW using my Canon T3i but haven’t had to time to really learn what that means. Related to SharpCap, I checked and I recorded the solar images in RGB24. What was interesting is the article mentioned that SharpCap has its code so the image on the screen will be in color. This explains my confusion.
So, I next wondered if I could get the images to display like I saw in the preview. I did another search and found this article https://forums.sharpcap.co.uk/viewtopic.php?t=254. It provides a link to a PDF which explains how to “debayer” the RAW images to display color. The process involves using a software called PIPP.
In PIPP, one of the question is what debayer patter was used. It said to do a search on the camera model. I did for the ZWO ASI034MC but didn’t get a result. Since, there are only four choices and just tried them and learned the correct patter was GRBG.
Here is the process I did to convert by SharpCap RAW8 files:
- Organize the RAW files into a folder
- Start PIPP
- Drag-and-drop the images into the Image Files List
- The Output Frame window appears to give a preview
- Select the Input Options tab
- Check – Debayer Monochrome Frames
- Select GRBG
- Click the “Test Options” to test image result
- Select Output Frame tab
- Select Do Procession tab
- Click Start Processing
- Click Open Output Folder to find results
For the AVI video, I just changed the Output Format to be AVI. But, I did to add each file individually or it joined them into one AVI.
Since another clear night, I wanted to try the ZWO camera with the Meade ETX. There was a slight breeze which made it more comfortable and keep away the mosquitoes.
I setup the power for the laptop and the DC adapter for the ETX. I went to plug in the ZWO camera but it wasn’t detected by the laptop. Then I remembered that I only installed SharpCap and forgot to install the camera drivers. Simple fix.
I decided to try the moon since it wasn’t fully dark. The moon was very large in the preview in SharpCap which was great. The electronic focuser on the ETX was nice but never really got a crisp image of the Moon. I would see the wavy appearance. Not sure if the hot night or the fact I was at the driveway but still learning a lot. I also realized I had forgotten all the settings for SharpCap. I just set to auto and hoped. I tried the Barlow too but it got way darker. Not sure if I can fix in the SharpCap settings so something to try at a later time.
I then went to fine Saturn. It was a very frustrating effort and took forever. I realized the finderscope wasn’t aligned correctly. I tried to compensate but swapping out different eyepiece but then realized that the higher magnification of the ZWO camera meant I needed to be perfect in the eyepiece before swapping with the camera. A couple of time I got close but then realized the exposure setting on SharpCap might not be helping. I had just set to auto. Finally, I noticed a donut and thought maybe I wasn’t in focus. But, we I focused, it move the telescope enough that Saturn moved. I went through this back and forth for a long time until I finally got lucky and got an image of Saturn in SharpCap. I was able to manually move the telescope once I realized the slowest setting was too slow for the actual motion of Saturn. I was able to get a few images but there would be no way to experiment with SharpCap settings. I then realized I needed to have tracking turned on by the telescope and thus need to have aligned it. It is all making sense and I guess trying makes you realize how much more you need to do. But, again, learning a lot.
I decided to try Mars next. It was slightly easier to get it into the SharpCap preview. I played around with the gain setting and got it to be sort of red but realized never going to get anywhere without tracking so just called it a night.
All the images can be found on the wiki at https://clearskytonight.com/wiki/July_26,_2018.
Tagged: ETX, Mars, Saturn, ZWO
It has been clear nights all this week so setup the Meade Lightbridge since Jupiter and Saturn are up at sunset and Mars would rise around 10:30 PM. Forgot to check the moon but it was also already up. I also decided to let the kids stay up late since so many targets to view.
Collimation went very easy. It was still hot out have a 89 degree days. Also for the first time noticed mosquitoes.
The moon was too bright in the Lightbridge. It left a shadow image in my eye.
Jupiter was similar to previous viewing sessions this summer. The moons had moved to two on each side.
Saturn was awesome. It was a little blurry but think I made out a ring division. But, overall it was just wow and my best view of Saturn so far.
I waited a hour for Mars to rise above the trees on the horizon. It was very big but still fuzzy. I wasn’t sure if the dust storm on Mars so that it was just too low to the horizon.
Great session overall.
Tagged: Jupiter, LightBridge, Mars, moon, Saturn