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Rolabi Wizenard
Sep 18, 2005

Make the Lakers Great Again


Golden-i posted:

The weather is finally clearing, and I can get out this weekend. I'd like to re-shoot the Whirlpool Galaxy, but am caught up on which scope to use.

-8" Newtonian, @1000mm focal length. Kinda crappy optics, more zoom
-Esprit80, @400mm focal length. Much better optics, but will lose some detail with the shorter focal length

Both scopes have focal flatteners. Which is the better scope to shoot with? I'm hoping someone ITT can give me a bit of help.

You might get a better answer from a more experienced astrophotographer, but I would say consider whether your seeing and your mount's tracking can support the additional detail the 8" may provide. The extra perfection in the sky and in your mount that would be required to fully realize the difference might be difficult to achieve.

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hannibal
Jul 27, 2001

[img-planes]

Golden-i posted:

The weather is finally clearing, and I can get out this weekend. I'd like to re-shoot the Whirlpool Galaxy, but am caught up on which scope to use.

-8" Newtonian, @1000mm focal length. Kinda crappy optics, more zoom
-Esprit80, @400mm focal length. Much better optics, but will lose some detail with the shorter focal length

Both scopes have focal flatteners. Which is the better scope to shoot with? I'm hoping someone ITT can give me a bit of help.
Stellarium can at least give you FoV comparisions. Good point from Rolabi about tracking with your Newt since they tend to be long. I like my 80mm refractor a lot because it's so small and easy to use but M51 is pretty small. I've been capturing some data on it with my 8" SCT lately.

my 80mm refractor in Stellarium

and an 8" f/5 Newt



and my 8" SCT


Also, don't forget about the New Horizons Parallax Program! Take a picture of Wolf 359 and/or Proxima Centauri next Thursday morning.
http://pluto.jhuapl.edu/Learn/Get-I...arallax-Program

For most NA observers the only one that works is Wolf 359 at 0400 UTC. It's a dim star but should be visible in photography in mid-range scopes. I'm gonna give it a shot tomorrow when it's supposed to be clear here.

AstroZamboni
Mar 8, 2007

Smoothing the Ice on Europa since 1997!

Finally packing it in after the first (near) all-nighter in the makeshift observatory.

Between the fact that I was getting better dark-adaptation, there were no lights distracting me, and I was observing with two fully-cooled scopes that complemented each other really well, I was pulling in stuff that I've never been able to see from in town before. In decent detail, no less.

A Proper Uppercut
Sep 30, 2008



Soo, questions regarding balancing this AD8. It has bearings that can adjust up and down the tube, but realistically don't I want to be able to move them away from the centerline of the long axis to get it really balanced? As it is, I think I'll only really be able to balance it at one specific angle and it's goin g to want to fall in either direction off that balance point.

So, I guess the questions are, how can I balance this in the other axis, and where should I adjust the balance point to with the existing setup?

AstroZamboni
Mar 8, 2007

Smoothing the Ice on Europa since 1997!

A Proper Uppercut posted:

Soo, questions regarding balancing this AD8. It has bearings that can adjust up and down the tube, but realistically don't I want to be able to move them away from the centerline of the long axis to get it really balanced? As it is, I think I'll only really be able to balance it at one specific angle and it's goin g to want to fall in either direction off that balance point.

So, I guess the questions are, how can I balance this in the other axis, and where should I adjust the balance point to with the existing setup?

It's going to be entirely dependent on how much weight you have up front on the tube. That's why they're adjustable. A lot of people attach a Telrad, or replace the focuser, or primarily use really heavy eyepieces like TeleVues. The more weight there is on the front end, the further up the tube the bearings need to be. Positioning of the altitude bearings is going to be entirely dependent on the equipment loadout YOU are using. Some people still need additional weight on the back end of the tube to make things balance. In that case, magnetic weights on the back end are the solution I use on my XT8 that doesn't have adjustable bearings. In such cases, it helps to position the weights at the back end on the underside of the tube, radially opposed to the focuser and finder. I doubt this step will be absolutely necessary if you're just using the stock AD8 accessories.

I believe the specific answer for you is to attach the finder, install your usual equipment loadout in the focuser, remove the dustcap and then play with the positioning of the bearings until your scope actually balances when positioned horizontally and the altitude bearings tension is loosened all the way. Further test it by nudging it up and down gently. If it keeps moving after pushing it in one direction (up or down) more aggressively than the other then you still have a slight imbalance. Once it's good, tighten the bearings into position on the tube and adjust to your preferred tension and go to town. If you ever attach a supplementary finder or switch to heavier eyepieces, you may need to repeat the process. I always like to keep a few small extra magnetic weights on hand as well for adjusting small imbalances like from using a Barlow.

Hasselblad
Dec 13, 2017
NRA shill who thinks homeless people would love to live in migrant border camps. Help me realize I am a bigoted piece of shit.


Isnít this the time of year gear and eyepieces go on sale? I may splurge for a field flattener and t mount for my D700.

Platystemon
Feb 13, 2012



A Proper Uppercut posted:

Soo, questions regarding balancing this AD8. It has bearings that can adjust up and down the tube, but realistically don't I want to be able to move them away from the centerline of the long axis to get it really balanced? As it is, I think I'll only really be able to balance it at one specific angle and it's goin g to want to fall in either direction off that balance point.

So, I guess the questions are, how can I balance this in the other axis, and where should I adjust the balance point to with the existing setup?

This can happen, and there are a few ways to fix it.

As you suggested, the bearing axis can be moved off the axis of the tube, so it intersects wherever the centre of mass is after all the accessories are added. Homebuilt telescopes may have provision to do this. Iíve never seen it on a commercial Dobsonian.

You can install counterweights to bring the centre of mass back to the tube axis. This is what I do. If, when you point the telescope low, the accessory weight is on the upper part of the tube, as is typical, youíll want to put the counterweights on what is the bottom part of the tube in that same orientation. I put them towards the mirror end to kill two birds with one stone. It doesnít matter if the centres of mass is left or right of the tube axis, i.e. biased toward one bearing or the other, just that itís not above or below it.



The third and funniest way is to hang something like a chain from the back of the mirror end. Then the telescope is pointed low and the leverage of the off‐centre accessories is greatest, more of the chain lifts off the ground, countering the effect.



This is, in my view, not the most elegant solution, but it apparently does work well enough.

Rolabi Wizenard
Sep 18, 2005

Make the Lakers Great Again



A Proper Uppercut
Sep 30, 2008



Okay, I thought I might have to go the counterweight route. Any recommendations on what to get exactly (that's not a dumbell haha). I do like the idea of the magnetic one so it can be adjusted as needed.

Thanks for the effortposts!

Platystemon
Feb 13, 2012



You could do worse than cast lead SCUBA weights.

Get coated ones so you donít spread brain poison around from handling them.

For adjustment, what I do is have a long strip of 3M Dual Lock. I adjust where along that strip I attach the weight. It can hold a lot of weight, and it doesnít creep and let go like velcro does when the telescope is tilted back and forth. The adhesive sticks well to my telescopeís paint even in freezing temperatures.



My most and least massive eyepieces vary by over a kilogram, so I do have to adjust for that. What I do is balance the bottom end of the telescope for the heaviest eyepiece (and coma corrector) and little bit more.

Then, to tune it for lighter eyepieces, I have a dual lock strip running along the side of the tube under the focuser and a three‐pound weight I can attach anywhere along it. When light eyepieces are in use, the weight goes near front end of the tube. When the heavy eyepiece is inserted, the weight goes near the bearing axis.

This system works all right for its simplicity. I do plan to upgrade it to some kind of a rail with a clamp, where I can press a button or turn a knob to allow the weight to slide along the rail and lock it in place where I want it. This would allow me to finely adjust the scopeís balance without disturbing its aim.

I havenít made that upgrade yet because itís really only the one heaviest eyepiece I have to adjust for. The others are within the margin of friction in the bearing. Disturbing the point of aim is rarely a problem for me.

AstroZamboni
Mar 8, 2007

Smoothing the Ice on Europa since 1997!

I use a whole bunch of these with felt glued to them so they don't scratch up the tube.

https://www.harborfreight.com/set-o...ooks-65528.html

They give me a lot of flexibility to adjust positioning to get optimal balance.

Rolabi Wizenard
Sep 18, 2005

Make the Lakers Great Again


Hereís another option.

http://www.scopestuff.com/ss_mwt1.htm

AstroZamboni
Mar 8, 2007

Smoothing the Ice on Europa since 1997!

High Point had dust caps for GSO Dobsonians on clearance so I ordered a replacement for my missing one. Wound up ordering the last two color filters I needed to complete my collection while I was at it. Planetary season is fast approaching and I plan on doing some planet sketching for the first time in forever.

Rolabi Wizenard
Sep 18, 2005

Make the Lakers Great Again


AstroZamboni posted:

High Point had dust caps for GSO Dobsonians on clearance so I ordered a replacement for my missing one. Wound up ordering the last two color filters I needed to complete my collection while I was at it. Planetary season is fast approaching and I plan on doing some planet sketching for the first time in forever.

Speaking of planet season, my kids have been eager to get up at 5AM to look at Jupiter, Saturn, and Mars. I drag the 100ED outside and itís been kicking some major rear end. I used to have a C102 achromat, and it took magnification well, but it would put up a noticeable purple halo around Jupiter and anything remotely bright. This FPL53 doublet is color free and sharp as hell even up at 200x. Iím going to break out the 150mm Russian Mak next clear morning and do a little comparison.

My middle child, 8yo girl, said Saturn had TWO rings, one inside one and outside. So I told her about the Cassini division and she told her mama all about it. Her older brother said Mars looked like it had a butt crack, there was/is what appears to be a nice dark region visible across the middle of the disk.

Itís already planet season if you get up early enough!

AstroZamboni
Mar 8, 2007

Smoothing the Ice on Europa since 1997!

Correction: it's already planet season WHEN you stay up LATE enough!

Unfortunately due to the roofs and trees of various neighborinos, I can't see the planets from my backyard observatory when they're up in the morning, so I gotta schlep everything around to the front yard which is a pain in the rear end when you're cold and fading from observing all night.

I think the next time I have to be up early for garbage day and it's not expected to rain or snow overnight, I'll set the 6" scope out back to acclimate all night and then drag them around to the front when I have to get up to haul the bins to the curb.

Edited to add:

Kinda jealous of your 100ed. Wish I had a good apo on a manual eq with a motor (I'm old school. I hate dealing with go-to systems). As it is my planetary scope is an older (late nineties, cardboard tube) Orion 6" f8 Dobsonian. The mirror was figured by Terry Ostahowski and takes magnification LIKE A BOSS, but it's taken a lot of modifications over the last 22 years to get it to perform to its real potential. Got it new when I was fourteen and been voiding the gently caress out of its warranty ever since. On a good night it's a planetary BEAST and I've bumped it up over 400x without the image breaking down. The problem is manual tracking above 400x is a bitch. I really need to build an equatorial platform for it.

I also have an old (99-03, pre-intelliscope) XT8 that I got used from a friend a few years ago for $75. It was in rough-rear end shape missing its original mount, having a partly caved-in tube, and needing some replacement hardware but nothing wrong with the optics. I spent some elbow grease and time refurbishing it into a REALLY nice scope. Managed to get an original XT8 base, pound out the dents, flock the tube, install Bob's knobs and a mirror fan, yadda yadda yadda. It definitely has an edge over the 6" on deep sky, but doesn't take magnification like the other one does, so ultimately they complement each other really well.

I might have to post photos of the weird poo poo I've done to the 6" scope sometime. It's a serious frankenscope at this point.

I've got a PST but it hasn't been seeing too much use lately as a result of solar minimum.

AstroZamboni fucked around with this message at 18:21 on Apr 24, 2020

Rolabi Wizenard
Sep 18, 2005

Make the Lakers Great Again


I had a bone stock XT6 and it performed very well, I bet that Terry O glass is incredible!

I liked that it was a one-trip-to-the-backyard scope, and quick to acclimatize. No dew issues, easy on eyepieces, comfortable to observe with, and easy to collimate. I have to have something like that for the nights that look good but I donít want to go through a huge set up for one hourís worth of observing before bed. The refractor is that for me these days.

A fat tracking dob (with wheels and handles) is in my future, if I can stop spending money screwing with EAA. Hyperstar, filters, cameras, and still experimenting.

You should post pics of your modded scope!

AstroZamboni
Mar 8, 2007

Smoothing the Ice on Europa since 1997!

Rolabi Wizenard posted:

I had a bone stock XT6 and it performed very well, I bet that Terry O glass is incredible!

You should post pics of your modded scope!

Believe it or not, all Orion Dobsonians prior to mid-1999 (the introduction of the "SkyQuest" brand coincided with a shift of manufacturing to Taiwan) had mirrors figured by Terry O. He was the head optician for Discovery Telescopes, and they were the manufacturer for Orion's dobs in the nineties. A lot of people who didn't hang on to them at the time are kicking themselves now because of it.

I will never part with that scope, but I may eventually build a new optical tube to house the optics. Eventually I want to build an optimized Newtonian assembly for the mirror with a curved spider, tiny secondary mirror with ultra-low profile focuser, flocked tube, rear AND upper boundary layer fans, recessed light trap opposite the focuser, and a bunch of other crazy poo poo. Haven't decided whether to do knife-edge baffles in it or not, but I'm probably going to build a mount with an integrated equatorial platform for it. I want to be able to do some planetary imaging with it.

I'm probably going to be setting up the makeshift observatory Monday night, so I'll just do pics of the whole current setup then.

A Proper Uppercut
Sep 30, 2008



Finally had some decent weather last night to get outside and mess around with my 8" dob. It was a lot of fun!

Unfortunately where I live, there's a lot of sky glow, so anything I saw wasn't clear at all. Going to need to drive at least 30 minutes to get an area of somewhat darker skies.

Using Turn Left at Orion, I was hunting for a couple galaxies in Virgo, near Vindemiatrix. I can't rememeber the numbers, but I was able to get a very faint shadow of them. I love the whole aspect of searching for landmarks to find your way around.

Does anyone have any recommendations for neat DSOs in the northern hemisphere that are visible the next few months?

Luneshot
Mar 10, 2014



A Proper Uppercut posted:

Finally had some decent weather last night to get outside and mess around with my 8" dob. It was a lot of fun!

Unfortunately where I live, there's a lot of sky glow, so anything I saw wasn't clear at all. Going to need to drive at least 30 minutes to get an area of somewhat darker skies.

Using Turn Left at Orion, I was hunting for a couple galaxies in Virgo, near Vindemiatrix. I can't rememeber the numbers, but I was able to get a very faint shadow of them. I love the whole aspect of searching for landmarks to find your way around.

Does anyone have any recommendations for neat DSOs in the northern hemisphere that are visible the next few months?

I'm glad you're enjoying it! I'll recommend a few of the brightest favorites that should be visible even with some skyglow.

Spring stuff:

Cancer: M44 (huge open star cluster, "Beehive"/"Praesepe")

Ursa Major/Canes Venatici area: M51, M81/M82, M63, M94, M106 (all galaxies), M3 (globular cluster).
M101 has a high integrated brightness, but it's spread over a large area so it's quite difficult to see- low "surface brightness".

Virgo/Coma/Leo: M87 (and basically the whole Virgo Cluster), NGC 4565, M66/M65/NGC 3628 ("Leo Triplet"), M104 (all galaxies)

Hydra (low in the south): NGC 3242 (planetary nebula "Ghost of Jupiter"), M83 (galaxy)

Late spring and early summer stuff:

Hercules: M13 (bright globular cluster, if you get to dark skies, look for this one naked-eye)
Don't overlook the nearby M92 globular either!

Serpens: M5 (globular cluster)

Draco: NGC 6543 (planetary nebula "Cat's Eye")

Summer stuff:
oh god where do I even start? Summer is for looking along the plane of the Milky Way.

Lyra: M57 (planetary nebula "Ring Nebula"), Epsilon Lyrae ("Double Double" star)

Cygnus: M29 and M39 (star cluster), Veil Nebula (this one can be difficult), Albireo (double star with great color contrast), NGC 6946 (galaxy)

Vulpecula: M27 (planetary nebula "Dumbbell"). don't bother trying to pick the actual constellation out, it's basically invisible

Sagitta: M71 (globular)

Scutum and Serpens Caput:: M11 (open cluster) and M16 ("Eagle" nebula)

Sagittarius: M22 (bright globular), M8 ("Lagoon" nebula), M20 ("Trifid" nebula), M17 ("Omega" nebula)
Jupiter, Saturn, Pluto (Pluto doesn't look like anything other than a star, but it's cool to see anyway)

Scorpius: M7 ("Ptolemy" open cluster), M4 (globular), M6 (open cluster)

That should be plenty to get you started, although no means is this even half of the cool objects. Start looking for the fall stuff on the other side of the Milky Way in a couple months, but by then you should hopefully have the hang of finding objects to look at.

If you're using Stellarium, I'd recommend messing with the DSO Labels in the "View Options" window, and checking the "Use Designations For Screen Labels" checkbox; objects will thus be identified onscreen by their Messier/Caldwell/NGC numbers instead of their common names. This is personal preference, though, whatever helps you remember them is fine!

AstroZamboni
Mar 8, 2007

Smoothing the Ice on Europa since 1997!

There's currently a Type II supernova easily visible in M61, high in the sky from around 10-midnight. I'll be setting up my porchservatory tonight to observe it. It's a good one even for moderately light polluted skies.

Platystemon
Feb 13, 2012



See also 2020hvf, mag 12.8 Ia in NGC 3643 (Leo)

Platystemon fucked around with this message at 23:34 on May 18, 2020

A Proper Uppercut
Sep 30, 2008



Thanks for all the suggestions, just gotta wait for some better weather.

So, I have a telrad mounted to my scope. I found that using that and a 28mm eyepiece worked better than using the finderscope. Is this common? Are there situations where the finder scope would work better? I was debating removing it entirely.

Platystemon
Feb 13, 2012



I have a Telrad and I use it for the initial hop and sometimes for shortcuts to objects Iím already familiar with, but when hunting faint fuzzies, I find a magnifying finder invaluable. The main scope canít show enough of the sky to starhop comfortably.

Itís extra frustrating with objects that donít show up in wide eypieces, like planetary nebulś. I think Iím in the right spot, swap to higher magnification and nothing is there. Am I slightly misaimed or off entirely? Who knows! With a finder scope, I just move my eye back there and reassess. Without one, I might be restarting the starhop from the beginning.

Not having a finder scope is especially a problem in light‐polluted areas. The naked eye stars are sparser. Thereís less to reference the Telrad on. Starhops start further from the object of desire, and there are fewer stars to reference in the eyepiece.

AstroZamboni
Mar 8, 2007

Smoothing the Ice on Europa since 1997!

If you're trying to use a Telrad in an area with limited stars visible due to light pollution, you might want to look at a new thing called the Quinsight. It's just one guy custom building them with a 3D printer, but it's kinda like a Telrad on steroids.

https://m.facebook.com/r2d2b2.rob.brown/

It's essentially a vertical Telrad with a larger window and additional 8į and 16į circles for being able to use much sparser star fields in light polluted skies. I've been seriously considering ordering one. It's easy enough to configure a custom reticle overlay in SkySafari that matches it so you can perfectly frame an invisible object using much more angularly distant stars.

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Yooper
Apr 30, 2012



Grimey Drawer

Hi astronomy thread. I've started to get into this and wanted to run my plan by you folks.


Biggened version

That was first decent night. I had originally planned on shooting the core of the Milky Way but there was a huge light pollution bulb from a paper mill about 5 miles away.

Current Gear
Canon T3
18-55mm Kit Lens

DeepSkyStacker/Sequator

On order is...
Skywatcher Sky Adventurer Pro
Dew Band
DSLR Noise Pollution Filter (SVBONY Cheapo)
Canon 50mm F1.8
Takumar 200mm F4 (With M42 thread adapter to Canon)

Anything else I should add to get me in better shape? I'm shooting in a Bortle 4-6 area in the upper Midwest of the US.

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