The other night I attempted my first telescope image using my telescope adapter with my Canon EOS Rebol XS DSLR camera. The initial results of my first telescope images are a bit disappointing. However, I did learn a thing or two which I look forward to addressing in the not to distant future.
I think it is also important to emphasize that well, I do not really know what I am doing yet. In a few months, I will laugh at the ridiculousness of this post and the setup and this post. Regardless, I believe in hands on learning and am looking forward to doing so.
I am using a National Geographic Telescope 60/700 as my primary lens for this venture. The reason for it is simple, this is the one I own and it was a gift from mom to my son and I for use on camping trips. I am sure that this is at best an entry level telescope, however my son enjoys using it on trips and it is readily available to me.
A few quick specs on this telescope. It has a 700 mm focal length and 60 mm front aperture which is works out to be 2.36 inches. The telescope kit included 2 eye pieces, a tripod, and a 2X Barlow lens to bring distant objects closer.
The telescope is connected to my Canon EOS Rebol Camera with a SVBONY Fully Metal 1.25″ T Adapter. When connected this adapter essentially converts the telescope into the primary lens for the camera. The camera must be focas manually. I used the LCD on back of the camera as a view finder, which makes it easier for others to see what is going on through the telescope.
The Imaging Setup
The initial testing for this endeavor was simple. Connected the T-ring adapter to the camera and then connect the camera to the 1.25 eyepiece of the telescope. However, once I started to use my setup, I had some concerns and issues.
The biggest concern is the balance of the telescope when the camera is connected. Once connected, the 0.99 lb camera quickly pulled the eyepiece end of the telescope down to the ground. Additionally, it occurred to me that I was connecting a $500 camera to a $100 telescope. The telescope camera connection was secured with a $0.10 thumbscrew. Not a good idea. This did not seem like something I should do if I hoped to keep my camera in good condition. So, out came the camera tripod.
Now, I had the camera secured on my Manfrotto tripod and connected using the T-Ring adapter to the telescope. The camera body was mounted on second tripod. Although unwieldy, this setup seemed to work and soon the moon filled my viewfinder.
My telescope has a focal length 700 mm, which used in conjunction with my DSLR camera is the equivalent of 1,120 mm and 2,240 mm when the 2X Barlow lens is utilized. Using this setup, I could visually observed the moon move in the viewfinder and the earth spins on its axis and the moon rotated in its orbit. In conjunction with having to quick manipulate two tripods and try to compose the image leads to a very busy photographer. My best results are achieved by initially placing the moon off center in the view finder and waiting for the moon to center in the objective. I did use a cable release to remove any vibrations caused my manually pressing the button on the camera.
The above full frame photograph is like many others I took. The moons hemisphere fills the image. My self criticism is the image is does not seem to be in crisp focus and seems a bit over exposed for my taste. Solving this focus problem is my primary concern and could be caused by a variety of issues, perhaps multiple. There are several potential causes to explain my focus problem. They are:
- The atmosphere – This no doubt is contributing and the reason that NASA uses space telescopes to remove the atmosphere from the equation. Other ground photographers achieve better images so the fault has to be mine, and there is nothing I can do to solve this problem.
- The Telescope Primary Lens – This has potential to be an issue, however, I do not believe that the telescope is the issue in this case.
- The 2X Barlow Lens – Additionally, this could be a big part of the equation. The Barlow lens which came with my telescope probably contains an inexpensive plastic lens. I have to believe that this is part of the issue. Additionally, the smaller subject matter will allow for more time for my to adjust my setup.
- The Camera / User – I am not willing to blame my camera, although it is possible my aging eyes need to be re-calibrate with the camera’s eye piece. I will ensure my eye piece is correctly in focus for my eyes.
- The imaging assembly – This is definitely part of the problem. With the moon high in the sky and utilizing two tripods allows for a lot of movement and puts the camera eye piece at knee level. An fast moving, uncomfortable photograph does not lead to quality images when focusing manually.
In the short term, I am going to image again soon without the Barlow lens. I also ensured my camera eyepiece is in focas. My belief is that addressing these two issues should dramatically improve the resulting photographs. Additionally, I know that there are moon filters available which may help the resulting image. However, I do not think for a second that a filter will solve the focus issue.
Moving forward, it is very clear to me that a dual tripod setup is at best unwieldy. This contribute to quality concerns beyond just usability. I believe I need to build a new balanced mount to create one solid assembly. This mount would preferably be incorporated with tripod which is taller, sturdier and should allow for more comfortable imaging sessions. Finally, I want to modify the camera and telescope connection to incorporate a mechanical lock. This will prevent accidental camera damge.