|
Good afternoon astronomy thread! This might be hopeless endeavour, but if it's doable, someone here would know. I have an 8" and 12" Orion dobsonian that I don't use nearly as much as I want to. I'd like to be able to take one out to a dark site or when I go camping, but I have a little problem: The stands/mounts for them don't even fit in my car. I could take them apart every time but that feels like a recipe for losing pieces. Has anyone here made or seen a stand that would be light and collapsible, but also sturdy enough to work with one of these? And a contribution, taken through the 12" with my phone. 
|
#
?
Feb 21, 2022 20:48
|
|
|
|
| # ? May 28, 2024 22:16 |
|
|
Hi All, Looking for peoples views on 1st camera, I dont really wanna be upcycling alot so would prefer a camera that is going to suit for a while. I've narrowed what I can afford down to either a 70d or 700d, the 70d is about $100 more than the 700d and has a few features like 20 vs 18mp but I dont think they matter overall that much? This would be a camera I'd like to get modded but looking at it nothing is jumping out at me as to WHY I would spend more for the 70d?
|
|
#
?
Feb 28, 2022 10:43
|
|
|
Beccara posted:Hi All, One thing is that if each generation of sensor will probably be better in so far as noise goes, but I believe those two use the same sensor and image processor (not a Canon guy.). I don’t expect there’s much of a difference at all between the two for taking photos of the sky. I think I’m starting to get the hang of the whole post-processing rigamarole. Clear tonight (Bortle 7-8) so I got a couple hours on what I like to call the Goatse nebula. 
Phanatic fucked around with this message at 05:38 on Mar 4, 2022 |
|
#
?
Mar 4, 2022 05:28
|
|
|
My dad has some land with a little cabin and a deck, quite low light pollution. A dobsonian would be the way to go here if he has room for it, right? He's not especially interested in photography and likes using the software he has on his laptop to track things down and point by hand. The only concern we had was the cabin gets quite hot/humid in the summer. If he has to put it on his little 4 wheeler mule thing and drive it to the larger barn to put in the cooler basement all the time that'll be a major pain, even with a collapsing/telescoping dobsonian. Also it would be cooler but still somewhat humid.
|
|
#
?
Mar 6, 2022 18:44
|
|
|
Well it's just a test of the 700d with a plain old 18-55mm lense but it was mainly just to muck about with the tool chain. Got alot to figure out on focusing https://astrob.in/tdxm1j/0/ https://imgur.com/ByrB3Rl
|
|
#
?
Mar 17, 2022 09:40
|
|
|
Beccara posted:Well it's just a test of the 700d with a plain old 18-55mm lense but it was mainly just to muck about with the tool chain. Got alot to figure out on focusing First light! I found a bahtinov mask to be a huge ease for focusing. It's still tough on a camera screen, but it's a hell of a lot easier than not having one.
|
|
#
?
Mar 17, 2022 12:38
|
|
|
And then there's dumb me, who has twice forgotten to take off the Baht mask before taking photos...
|
|
#
?
Mar 17, 2022 19:47
|
|
|
Yooper posted:First light! I'm sure it's just cos i'm being thick but I can't see jack all on the screen and barely anything thru the viewfinder. APT and BYEOS give me noise on the lives. I'm finding I have to do 5s exposure's and twist the focus ring a bit, it wont be helping that it's full moon with a scattering of cloud cover and it's using the kit lense thats 18-55mm f/5.?, I may delay the mount for a month or two and get a f/1.4/2/2.8 lense in the 75-135mm range Time to see if I can 3d print a bahtinov mask for the lens!
|
|
#
?
Mar 17, 2022 21:31
|
|
|
Beccara posted:I'm sure it's just cos i'm being thick but I can't see jack all on the screen and barely anything thru the viewfinder. APT and BYEOS give me noise on the lives. I'm finding I have to do 5s exposure's and twist the focus ring a bit, it wont be helping that it's full moon with a scattering of cloud cover and it's using the kit lense thats 18-55mm f/5.?, I may delay the mount for a month or two and get a f/1.4/2/2.8 lense in the 75-135mm range Yah, focus lens are like that.  This is a good chart to show you how much more light you collect from a lower F number. The zoom part makes it extra tough as it has to fit the zoom mechanism inside as well. I've 3D printed quite a few bahtinovs. The one I liked best ran through OpenSCAD and let you vary slots, width, diameter, etc.
|
|
#
?
Mar 17, 2022 22:10
|
|
|
Beccara posted:I'm sure it's just cos i'm being thick but I can't see jack all on the screen and barely anything thru the viewfinder. APT and BYEOS give me noise on the lives. I'm finding I have to do 5s exposure's and twist the focus ring a bit, it wont be helping that it's full moon with a scattering of cloud cover and it's using the kit lense thats 18-55mm f/5.?, I may delay the mount for a month or two and get a f/1.4/2/2.8 lense in the 75-135mm range The moon actually makes focusing easier. It just makes everything else harder. Use the moon to focus. Worst case, you know where near focus is on your lens and can use a mask to get finer focus later when there isn't a moon. But just remember that with a bahtinov mask, the brighter the star, the better.
|
|
#
?
Mar 17, 2022 22:16
|
|
|
Out of curiosity, do any of y'all have any experience with the PoleMaster? I'm thinking about picking one up around tax return time since the polar scope + adapter combo for my iEXOS-100 is out of stock / backordered everywhere I look. There's no official adapter for my mount, but from the poking around i've done it looks like I can either have one 3D printed or I can buy an adapter to mount it to my dovetail that my DSLR is mounted to. I figure this is a cheaper and easier way of polar aligning than going with a full on dedicated guide camera / guide scope for the time being and it's way better than my current method of "Use my phone along with StarWalk / Stellarium to get everything pointed in vaguely the right area" because the factory boresight on this mount is absolute rear end 
|
|
#
?
Mar 17, 2022 23:44
|
|
|
T1g4h posted:Out of curiosity, do any of y'all have any experience with the PoleMaster? I'm thinking about picking one up around tax return time since the polar scope + adapter combo for my iEXOS-100 is out of stock / backordered everywhere I look. There's no official adapter for my mount, but from the poking around i've done it looks like I can either have one 3D printed or I can buy an adapter to mount it to my dovetail that my DSLR is mounted to. I figure this is a cheaper and easier way of polar aligning than going with a full on dedicated guide camera / guide scope for the time being and it's way better than my current method of "Use my phone along with StarWalk / Stellarium to get everything pointed in vaguely the right area" because the factory boresight on this mount is absolute rear end I'm going to assume that you're talking astrophotography here. What are you using for acquisition? Both NINA ($Free) and Sharpcap ($10 or $15/year, I think) have pretty good polar alignment features. They'll use whatever camera you have. It doesn't have to be a guide camera, and in fact, you could definitely make the argument that using your main imaging camera is more accurate. Both will work with a manual mount and a go to mount.
|
|
#
?
Mar 18, 2022 00:15
|
|
|
simble posted:I'm going to assume that you're talking astrophotography here. What are you using for acquisition? Both NINA ($Free) and Sharpcap ($10 or $15/year, I think) have pretty good polar alignment features. They'll use whatever camera you have. It doesn't have to be a guide camera, and in fact, you could definitely make the argument that using your main imaging camera is more accurate. Both will work with a manual mount and a go to mount. Astrophotography, yeah. I'm using a Canon T2i with a 70-300mm Sigma for most of my shots. I haven't actually tried NINA / Sharpcap to be totally honest, I've been playing with the stock Explore Scientific app and doing 2 / 3 star alignments that way without ever hooking my camera to my laptop. I genuinely never thought about trying to hook it up if I'm being honest, Explore Scientific's app communicates over WiFi by default so I've been using that. I know it has drivers for ASCOM but I know nothing about that and have never delved into learning it.
|
|
#
?
Mar 18, 2022 00:24
|
|
|
T1g4h posted:Astrophotography, yeah. I'm using a Canon T2i with a 70-300mm Sigma for most of my shots. I haven't actually tried NINA / Sharpcap to be totally honest, I've been playing with the stock Explore Scientific app and doing 2 / 3 star alignments that way without ever hooking my camera to my laptop. I genuinely never thought about trying to hook it up if I'm being honest, Explore Scientific's app communicates over WiFi by default so I've been using that. I know it has drivers for ASCOM but I know nothing about that and have never delved into learning it. Can the polemaster be used without a computer? I genuinely don't know and glancing at the docs it looks like no. If it can, then that would be good enough. If you need a computer anyway, then try one of the apps first. I think you'll find them needs suiting. For Canon stuff with ASCOM, you'll want this ASCOM driver: https://github.com/FearL0rd/ASCOM.DSLR Which mount are you using? It sounds like its a goto if you're aligning it with a 2/3 star alignment. With NINA and ASTAP (plate solver) you could ditch your alignment completely by doing a blind plate solve and syncing your mount after a polar alignment. If at that point you wanted to just unplug the computer and use the wifi with a shutter control, you could do that at that point as everything will be aligned and pointing correctly. Or, if you want you can delve into using NINA to do your captures for you. If you do use NINA, use the latest beta version.
|
|
#
?
Mar 18, 2022 00:36
|
|
|
T1g4h posted:Astrophotography, yeah. I'm using a Canon T2i with a 70-300mm Sigma for most of my shots. I haven't actually tried NINA / Sharpcap to be totally honest, I've been playing with the stock Explore Scientific app and doing 2 / 3 star alignments that way without ever hooking my camera to my laptop. I genuinely never thought about trying to hook it up if I'm being honest, Explore Scientific's app communicates over WiFi by default so I've been using that. I know it has drivers for ASCOM but I know nothing about that and have never delved into learning it. I use SharpCap, or at least once cloudy season is done with. All it needs to talk to is the camera, you do manual mount movements per instructions. NINA has a method too, I've not used it, but you don't even need to see Polaris to do it.
|
|
#
?
Mar 18, 2022 00:37
|
|
|
simble posted:Can the polemaster be used without a computer? I genuinely don't know and glancing at the docs it looks like no. If it can, then that would be good enough. If you need a computer anyway, then try one of the apps first. I think you'll find them needs suiting. Sorry, I should have specified! I'm currently using an iEXOS-100 GoTo mount, controlled over its own WiFi hotspot via laptop and the Explore Scientific ExploreStars app. That's what I mean when I say I have never tried the ASCOM drivers and things like NINA. I know the mount supports them at least, ES has their own set of ASCOM drivers for the iEXOS-100 and I believe a client? Up until now the mount has been collecting dust while I waited on warmer weather, hence me not getting a chance to fully dive into everything  I've been using just a normal cable shutter release for the actual camera, and doing all my slewing / GoTo stuff via the laptop and ExploreStars, but if NINA can handle both the actual alignment process and telling the mount where to go, I might have to look into trying that instead. The ExploreStars app is nice since it has all the movement controls and a database of Messier objects, but I'm not opposed to switching if NINA has the same functionality and more, I just don't know anything about it
|
|
#
?
Mar 18, 2022 00:55
|
|
|
Yooper posted:
...because I don't come from the camera side of things, I see your diagram as a single scope drawn with a series of different aperture masks. Same glass, same focal length, so focal ratio increases as you artificially reduce the aperture. It's more intuitive to me to assume that the more aperture you have, the more light you collect, but I hear it said your way more often when people talk about cameras, like the ratio is what matters. Like a 50mm f/2 would collect more light than a 50mm f/4. Is there a better way to understand this? Camera guys seem to be telling me that a steeper light cone "gathers more light" than a less steep light cone of a given aperture. Seems counter intuitive.
|
|
#
?
Mar 21, 2022 21:57
|
|
|
Welp, this hobby can be dangerous. Was in a major city 3 hours away for work, near a camera store and thought maybe just before i go buy a tracking mount a decent lens would be worth it to.... So now i have a Cannon 50mm F1.8 STM
|
|
#
?
Mar 21, 2022 22:04
|
|
|
duodenum posted:Is there a better way to understand this? Camera guys seem to be telling me that a steeper light cone "gathers more light" than a less steep light cone of a given aperture. Seems counter intuitive. Think of your lens as a bucket to gather stray rain drops. The larger the bucket, the more stray rain drops you can catch. Having a tight bucket that is very long lets you focus your bucket, but the top of it is still narrow. In astrophotography photons are scarce, so we want as wide a bucket to capture them. Bright things, like planets, allow you to use a very large focal ratio so as to get the magnification because you have a ton of photons to work with. On the flip side dim things, like nebula, are reaalllllly big, but realllly faint, so we need a big wide scope to capture the scant photons that they produce. https://cloudbreakoptics.com/blogs/...%3D%20f%2F6.25.
|
|
#
?
Mar 21, 2022 22:45
|
|
|
All I think about in terms of aperture is that each stop towards a smaller number doubles the amount of light that passes through. Each stop towards a bigger number halves the light. There’s also depth of field to consider but that’s irrelevant for astro photography. Or diffraction, which also doesn’t matter for astro because it only comes into play at apertures smaller than f/16. Doing astro? Biggest aperture possible!
|
|
#
?
Mar 22, 2022 00:03
|
|
|
xzzy posted:apertures smaller than f/16. This illustrates part of the problem! A focal ratio is not an aperture! *shakes fist at the sky Coming from the telescope side of things, camera guys’ terminology is a befuddling minefield of insanity. Probably because they’re used to a fixed aperture lens with an iris inside controlled by a ring labeled with focal ratios. They think in terms of ratios but they’re actually physically stopping down their aperture. Less aperture, less light! With only telescope experience, considering an objective lens of a fixed aperture, if you change it’s focal length and move it closer to the observer, the observer can see more of the sky through it. Like stepping closer to a porthole and looking out to the left and right. Wider field. More sky, more light. You’d still get the same amount of light from a given sky object, but you’d get more light overall in the wider field you’ve given yourself. There’s got to be more to it than this but that’s as close as I get so far.
|
|
#
?
Mar 22, 2022 23:37
|
|
|
Yeah, sorry. I'm a photo guy first and an astro guy second and I saw posts talking about cameras so I'm talking from that world. Life gets fun when two hobbies collide that use the same word to describe different design features. I don't think of ratios at all. I only worry about field of view and depth of field (and time and ISO).
|
|
#
?
Mar 23, 2022 00:00
|
|
|
I am sorry if I came across as abrasive, it's my problem-of-understanding and I appreciate you chipping in to help. No shade on you or the camera crew. 👍
|
|
#
?
Mar 23, 2022 00:31
|
|
|
So starting to learn post processing a bit, something i've noticed in PixInsight and Photoshop is this "streaking" https://imgur.com/a/4yaSEBo So far I havent found a term for it, does anyone know whats its called or what it's caused by? It's across the entire frame
|
|
#
?
Mar 24, 2022 03:55
|
|
|
What camera and what settings made that frame? I don't know that it has a specific name but "sensor banding" I what I call it and gives lots of hits in google if you want to read about it.
|
|
#
?
Mar 24, 2022 04:34
|
|
|
Generally in the AP world, that’s called walking noise. It’s almost impossible to get rid of after the fact. The way to avoid it is with dithering, if you’re guiding.
|
|
#
?
Mar 24, 2022 04:40
|
|
|
Cannon 700d, 50mm prime lens, 8s exposures on a plain old tripod
|
|
#
?
Mar 24, 2022 04:48
|
|
|
Beccara posted:Cannon 700d, 50mm prime lens, 8s exposures on a plain old tripod 100% walking noise. I had terrible issues with it on my Canon T3. Dithering is the only way to get rid of it. You can manually dither but a guide camera makes it so easy. Especially for lots of exposures.
|
|
#
?
Mar 24, 2022 13:19
|
|
|
Canon is notorious for banding. I think only their newest bodies have started to mitigate it.
|
|
#
?
Mar 24, 2022 15:23
|
|
|
Anyone know what the gently caress this is? The second picture might clue someone in on why I'm asking ITT. (Not the coffee pot, I know what a coffee pot is.) 
|
|
#
?
Mar 24, 2022 22:13
|
|
|
Oh wow, that's one hell of a provenance. I'm actually reasonably certain the instrument in question is a microscope, but that's cool as hell.
|
|
#
?
Mar 24, 2022 22:51
|
|
|
AstroZamboni posted:Oh wow, that's one hell of a provenance. That was my thought, but it's just so... rudimentary. The weird thing is I don't think I've ever seen it before, but it has to have been in the family since the early 1990s at the latest, and probably much longer.
|
|
#
?
Mar 24, 2022 23:40
|
|
|
The Wizard of Tuorla is a cool nickname Probably this https://www.astro.utu.fi/research/telescopes/40cm.htm
|
|
#
?
Mar 24, 2022 23:54
|
|
|
8” dob for $280, shipped. https://www.bhphotovideo.com/c/product/802389233-USE/sky_watcher_s11610_8_f_5_9_traditional_dobsonian.html
|
|
#
?
Apr 16, 2022 20:01
|
|
|
duodenum posted:8” dob for $280, shipped. Well that certainly won't still be in my cart when they open their store again on the 24th.
|
|
#
?
Apr 17, 2022 15:27
|
|
|
Finally had some clear skies and some time to do some astrophotography and I ended up calling it quits in frustration. I feel like it's always something different that I'm having trouble with and I'm just not good enough at it yet. And it feels like it's impossible to actually practice. Frustrating.
|
|
#
?
May 1, 2022 06:40
|
|
|
Internet Explorer posted:Finally had some clear skies and some time to do some astrophotography and I ended up calling it quits in frustration. I feel like it's always something different that I'm having trouble with and I'm just not good enough at it yet. And it feels like it's impossible to actually practice. Are you me? It was 4.5 months since my last night doing AP. I had about the same experience. I set up on Wednesday and had three targets. Markarians, M5, and Bode's. I forgot that I can't use auto-focus with my scope, if I do I get really nasty chromatic aberration. Supposedly it's an issue with the earlier Radian Raptor scopes, I reached out to OPT, but I got sick of bugging them about it. If I use a bahtinov mask then it works great, no CA. On the plus side my nightly troubleshooting is getting shorter. But it always seems like it's something. I'm looking at pouring a small concrete pad, adding a pier, and just leaving the rig outside with one of those Telegizmos 365 covers on it. Now I see the appeal in folks with those backyard observatories. Like I need that...  Now I'm digging into a handful of subpar sub sets to re-learn the processing workflow.  
|
|
#
?
May 1, 2022 11:59
|
|
|
I don't really know what I'm doing yet, but I took a couple of nebula shots tonight, just single shots Canon 5dmk4 on a eq6-r mount  
Raikyn fucked around with this message at 13:01 on May 1, 2022 |
|
#
?
May 1, 2022 12:58
|
|
|
Internet Explorer posted:Finally had some clear skies and some time to do some astrophotography and I ended up calling it quits in frustration. I feel like it's always something different that I'm having trouble with and I'm just not good enough at it yet. And it feels like it's impossible to actually practice. Man, I feel this to the depths of my soul. Between work and constant rain, I have had maybe 2 days where I could set up everything and practice, and both of those times were spent teaching myself how to use NINA and ASTAP. I think I finally worked out everything but I don't have any actual photos to show for it because, go figure, more rain is moving in and I've been busy working These are awesome. Raikyn posted:I don't really know what I'm doing yet, but I took a couple of nebula shots tonight, just single shots These are also awesome! You guys are seriously good at this.
|
|
#
?
May 2, 2022 06:01
|
|
|
|
| # ? May 28, 2024 22:16 |
|
|
10” dob, $420 (nice) https://www.bhphotovideo.com/c/product/802320652-USE/sky_watcher_s11620_10_f_4_7_traditional_dobsonian.html 8” dob, $300 https://www.bhphotovideo.com/c/product/802405237-USE/sky_watcher_s11610_8_f_5_9_traditional_dobsonian.html
|
|
#
?
May 4, 2022 15:06
|
|