For years I was convinced that I had set my expectations too high, having been continually disappointed with every single shot, until one day I remembered the word "collimation," which I had been too impatient and too lazy to attempt. When I did finally, I was both astounded and embarrassed. It took me all of 10 minutes to make my telescope right, and the fog on my photos was finally lifted, literally.
Before Collimation After Collimation
Look at the two images of Saturn I captured using a Celestron 8" Edge HD, on a Losmandy GM811g mount and tripod. I used a ZWO290mm mini guide camera as my primary imager, so I didn't have any guiding other than really good polar alignment and the mount speed set at 5 (which was a bit slow, but I didn't have the patience to find the sweet spot, when there probably wouldn't be one, which is why I usually use tracking software, which I couldn't use this time, because I was using my guide camera as my planetary imager), whatever.
To get the biggest image possible I used a Televue 5x barlow. So, here's the thing about barlow lenses; I've always hated them, because images would always look far worse with them, and it was never worth seeing an image magnified if it was going to make me feel like I had cataracts. I'll come back to that.
I then stacked the image on Autostakkert, which really means (in my case), the image above is the product of stacking about 10,000 images from video I captured using the ZWO software, ASICap, great stuff, I love it.
Sooooo, coming back to the topic at hand, collimation, patience, precision and barlow lenses (yes, I added the barlow lenses to it, because it's an important component).
Let's begin with the barlow. I have always read that barlows reduce the light greatly, which of course makes sense because you are reducing the focal ratio and the field of view, but it never explained to me why images had to be so many times more cloudy--darker I understand of course, but not cloudy.
So, one hot night in August when I had three tropical systems pulling the moisture away from my South Florida backyard during an otherwise typically wet season, I remembered this concept called "collimation" which I was supposed to do when I first purchased the telescope, but didn't because when I tested for it, everything was fine. But now I was annoyed by the star sparkles when using an eyepiece, because I had noticed for the first time that they were looking uneven. They would sparkle more to the left.
So, I blurred the star to see if it looked like an even donut, such that it was the same thickness going all the way around, and it was, but as I focused, and the donut walls closed in on the star, it was revealed that it was slightly off center.
So, I began to tighten and loosen the screws on the corrector plate attached to the secondary mirror at the front of the telescope, and then looking at the star through the eyepiece (I know, if I smart, I would have just used the ASICap imager to see it on my laptop, but hey, it was 3 something in the morning, and I wasn't my sharpest).
Once I had the whole in the donut centered I would tighten the focus and further adjust, and I would do this about three times (adjust, walk around to the eyepiece and look at star, go back to the front, adjust...) until I had a nice symmetrical sparkle at the end of the whole process.
When I was done, it was 3:30 in the morning, and the full moon was still out. So, I slewed over to it, and thought about doing something stupid and a complete waste of time and attaching the 5x, and then I thought "Whatever, go for gusto," and I attached the worst case scenario, the 5x barlow, and looked.
The moon was crystal clear. Usually, with the 2x it's a little hazier, and with the 5x the image would be disgusting. This was so clear I had to turn on my flashlight, look at my eyepiece, because, being tired, I thought maybe in my then current state, I had accidentally attached the 2x, or maybe I had fallen asleep and dreamt that I attached the 5x, or maybe I absent-mindedly forgot to attach it, but because I had intended on doing so I somehow got the idea in my head that I had, when I hadn't (like forgetting to flush the toilet when you thought you had and blaming it on the kids).
But no, I hadn't hallucinated, forgotten, or dreamt, I was really looking through the 5x barlow. No...freaking...way!
Quick, let me see what Jupiter looks like! It was much better. Capture some video to stack! Meh, results were okay. How about in color! Swap out the ZWO for the 45.7 megapixel Nikon D850 with full frame CMOS! Images were smaller than with the ZWO. Darn. What about Saturn? It's a lot fainter, so be prepared to be disappointed.
Wow! I can see the Cassini Division! Quick, capture some images! Much better! Do it in color! Nice (smaller, but nice).
I know what those of you residing at higher elevations are probably thinking, "Still not great you stupid, impatient caveman."
Yes, it's true that these images are not as clear as those I saw other folks take, but you have to understand that I'm at sea-level, well, about 4 feet above it (plus 3 or 4 more for the tripod and mount). It's so bad here, that when I'm taking video of a planet, it moves as if I were taking video of an image at the bottom of a pool--from outside the pool. And, since this is the middle of the wet season (even if much of the moisture is being pulled away by a hurricane to the west, a tropical depression to the north and a tropical storm to the east), all those miles of moisture that I'm peering through are probably piled up and made denser by the narrow field of view and high magnification of my perspective at sea level.
In any case, I can be so stupid sometimes. I should have collimated every time I used my telescope. Don't be like me.
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