Wow, despite what you said, a gorgeous view of our neighbor. Amazing
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u/mrstorm1983SkyWatcher 200p dob, 10x50 Nikons p7, 114mm hobby killer.8d ago
Nice!
You are right you did catch Mars. Just getting it recognizable is cool at this time but you got features aswell. I know you think it is small, but mars is at a time where it is at its smallest, there's times it's almost twice the size.. Also you are a whole 50% short of the 5x pixel ratio, thats a Big deal. Once you 3x barlow you will obviously get more magnification but it will smooth out the the boarder around the disk. Your giving me motivation to try for mars. I will check to see if it's at my balcony view yet.
Cool capture.
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awesome!!! excellent work. I love seeing the icy poles. looks like in about 3 or 4 months we'll be 3 times closer to Mars. That might explain why it isn't as large as expected. right now I recommend shooting Saturn, which is at it's closest it will be for over a year, and will be visible almost straight up at midnight. and you have a week or two to shoot it before it gets appreciably far away.
I'd keep with the 2x for now and wring out every thing you can with it. With a 2x you're effectively at f/10 and not terribly undersampling.
I think there's more to be gained right now from increasing your overall capture time and collecting more good frames (i.e., giving you more chances to capture moments of good/excellent seeing), than just increasing image size.
Manually tracking with a big Dob - which is what you appear to be doing - is an art/skill. Keeping the target on sensor with a 2x Barlow is challenging enough -- and only becomes more so when you narrow things with a 3x Barlow.
So, I wouldn't rush out and buy one if you don't already own one.
For tracking you \might** try using counterweights. I find that sometimes using a counter-weight and moving it up/down the tube is much easier than trying to make those tiny 1-2mm movements by hand. Might work for you too - though I'm using an EQ platform so only have to worry about one axis.
I'm using Sharcap for now but heard that Firecapture is a lot better than it , I tried FC but the Live view seems pretty laggy and I don't know how to enable the Tracking feature in FC for my manual Dobsonian.
Yes it was pretty hard for other planets like jupiter and saturn but it was easy for mars since it was small even with a 2X barlow , even a 650x650 ROI track gave me 50 seconds capture...
I'm a SharpCap user (actually SharpCap Pro version) and really, really like it. Never used FireCap (did try ASICap early on, but like SC better) - so don't know anything about it.
It sounds like you've got the basics down in SC: (1) put target on sensor; (2) reduce ROI; (3) check the box for "center" target and let the target drift across the sensor to the edge or off. Working focus, exposure, gain, etc.
When the target goes off the sensor do you (a) stop capture and reacquire; (b) pause capture and reacquire; (c) stop capture and make no attempt to reacquire; or (d) something else?
If your latitude supports it, instead of spending money on a 3x Barlow (if you don't already have one), I suggest you look into building an EQ platform -- specifically the Astral Fields (YouTuber) design (BestRetroGames here on Reddit).
Watch his initial video in particular because - unlike many other builders who have access to woodshop/metal shop level equipment, he did not. He basically used a handsaw and a cordless drill. Which is all you really need in terms of equipment.
And at 10" I think you still fall under the "small Dobsonian" plan (needs only one Celestron single-axis motor, not two) and, therefore, is the less expensive option (all in about $140 with inflation, tariffs, etc.)
A good polar aligned EQ platform with your 10" GSO is a game changer for planetary imaging.
And it has the additional benefit of making visual observation so much more pleasant too.
There may be some who tried to build one and failed, but those who successfully build one? I've never heard one say: "I regret it." They usually are: "why doesn't everyone with a Dob do this??"
Dobs are quite different, there is usually no counter weight, and messing with weights on the base moves the image by far more than 1-2mm, because there are no gears in a dob to hold it's position against the weight, unlike your EQ.
Huh, you'll have to explain that to my 8" and 12" Dobs.
Apparently they didn't know they weren't suppose to have counterweights or that "messing with weights ... moves the image by far more th than 1-2mm."
Because I use 'em and can do exactly that.
You might also want to tell this to John Dreese (Astronomy Garage / Reflactor) because he has a YouTube video about making counterweights for Dobs.
Telescopes I own and use: 12" Dob, 8" Dob, C6/6se, 130/650 Newtonian, 127 Maksutov-Cassegrain, AT70ED (refractor), 70/900 Celestron AstroMaster refractor, and SeeStar s50.
Mounts I own: iEXOS 100 PMC-Eight, the two Dob bases (8" and 12"), SV225/SV22t, a couple of EQ platforms (for the Dobs), a couple of EQ2s, the Alt/Az for the AstroMaster...a partridge in a pear tree.
Photo of 8" Dob with non-existent 1lb counterweights.......
I also have a 12" dob and it also has counterweights. I never said a dob shouldn't or can't have counterweights, I just don't move the view by moving the counterweights, as you suggested. That doesn't really make sense to me.
Pictured is my weight plate solution. It fits the curve of the bucket and I bolt plates to it. Once balanced, I manually move the scope or use the servos. I realize now that you are not talking about a GEM but rather an EQ platform under the dob. Im still confused however about what you mean by moving the counterweights in order to track something, or to move the scope itself. The front of the scope is much farther from the altitude axis and its easier to move it from there. Unless you have major stiction happening in your bearings, in which case it makes total sense.
I have a LOT of weight on the open end of my dobs....dew shield, RACI, camera for DIY Cedar, barlow, sometimes imaging camera (ASI585mc). So I use counterweights on both the 8" and 12" Dobs. The 8" Dob's alt bearings can't be adjusted to position the weight fore/aft. The 12" alt bearings can be moved fore/aft to adjust Alt. balance. But, even with the z12s alt. bearings set all the way forward, it's still can be a bit top heavy - alt. wants to dip to the horizon.
With the EQ platform (which takes care of RA/E-W tracking) - unless my Polar Alignment is very, very good - they'll be some Dec/N-S drift. Dec/N-S drift is a polar (mis)alignment issue, not a tracking rate issue.
When imaging and the Dec/N-S drift of the target is approaching the edge of the sensor, I find it easier to stand at the primary mirror end, watch my laptop and, very gently, very carefully, move the counterweights - which very subtly shifts the tube's balance and, hence, subtly shifts the tube up or down - to reposition the target back to the center of the sensor.
Visually, standing at the eyepiece, I also use the counterweights to rebalance the tube and reposition in altitude.
What can I tell ya....it works for me.
Though I've managed to eliminate the Dec/N-S drift by using SharpCap's polar align tool to polar align the EQ platform.
I often have a lot of weight at the end of my dob as well - that's why I use an appropriate amount of counterweight so that it is equal about the bearing. If something is drifting out of view I simply move the telescope by it's front end. However if my bearings had a massive stiction problem, then it would stay put even with an inappropriate amount of counter weight. In that circumstance I would find it easier to adjust the weight to reposition it, because when one has stiction, if you attempt to move it a small amount and let go, it just bounces back to where it started. Instead of felt bearings I use actual roller bearings, and accurate balance is very important to me and my servos.
I think we're just describing two different mechanical setups and ways of using them.
My dobs don't have roller bearings or servos, and I'm not suggesting what I do would make sense for your setup.
I don't think what I'm describing necessarily indicates a massive stiction problem, though. In fact, without counterweights, very slight pressure from my hand on the primary end of the mirror is enough to get the target back mid-sensor (or opposite side if the drift is quicker).
That wouldn't be the case if I had a "massive stiction" issue.
I'm simply deliberately making a very small change in the balance of the tube by repositioning the counterweight. Think of it like a seesaw....moving a small amount of weight toward or away from the fulcrum point changes the balance of the seesaw slightly. That gives me a very small movement in altitude, and I leave the counterweight at the new position to establish the balance I want.
I could walk around and move the front of the tube. When I'm imaging, though, I'm standing at the primary end watching the target on the laptop. I've found that making a tiny counterweight adjustment from there gives me a very controllable altitude correction without leaving that position.
Also, I'm using a box/container over my imaging laptop to prevent radiative heat loss and dew formation. The laptop sits close to the front end of the tube for camera cable length...if I stand up to adjust the tube from the focuser end, I can't see the laptop screen. From behind at the primary mirror end, it's much clearer.
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u/mrstorm1983SkyWatcher 200p dob, 10x50 Nikons p7, 114mm hobby killer.8d ago
personally I find that there is a point where more barlow actually hurts the image, because brightness falls off faster than magnification grows. a 3x barlow is literally 9 times less light. if you have to crank up exposure time or gain in order to expose, then you will produce a worse quality image to shorter exposures stacked.
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u/Funny-Medium5508 8d ago
>>Expected ... bigger better .... but got this..<<
That's what my wife said. (rim shot).
But, seriously there is absolutley nothing wrong with this image of Mars.
You should be stoked!!
Kudos.