61 replies to this topic

[Tony Flanders]

Any light pollution starts fast degrading and completely blocking visibility of "surface" objects.
For point sources like stars, magnification increases contrast between background and them, but for surface sources that doesn't help.

No, I wouldn't say that's true. On the contrary, I have found fairly high magnifications crucial to detecting many objects with low surface brightness, especially when observing under light-polluted skies.

Technically, increasing the magnification doesn't alter the contrast -- if you define contrast as the ratio between the object's surface brightness and the background sky. But faint objects that are subtle or even completely invisible at 5X per inch of aperture are often quite obvious at 15X per inch of aperture.

[Nankins]

Welcome to Cloudy Nights!  

 

That AD8 will give you years of enjoyment if you manage to use it enough to keep the dust off.   Keep up the good work with all the starhopping.... it's hard when you first learn the starhops but once you learn them it's more fun - not only do you get to learn the patterns in the sky more intimately than most people, you also get to the point where you start paying more attention to the color and magnitude variations in individual stars.  

 

Glad you were able to find M57.... as one of the brightest planetary nebulae (one of the brightest nebulae around for that matter!), it's one of the best objects in the sky.  If you have dark skies and know where to look, you might be able to locate it as a small grey dot in small-to-mid-sized binoculars.  Here's how I remember where it is:  Just point the telescope literally halfway between the end stars in Lyra (where the strings would be in a real lyre) and move it very slightly left.  

 

I second that you should get a Telrad, especially since you know the sky by naked eye.  It will save a ton of time and nicely complement the finderscope.  I would also suggest finding extra double sided tape or something to hold the finderscope mount down - it will get knocked around over time through usage and transportation and eventually start coming slightly loose.  

 

Plossls - there are actually many different brands, and in fact you can get good eyepieces that are Plossls.  The 9 mm that Apertura puts in their scope packages is good for starters - it's better than some out there.  Once you really get going in the hobby you will want to add other eyepieces aside from the 25 mm.  Especially for locating objects.  The 30 mm eyepieces really help with that - if you got the 30 mm eyepiece in the package with the scope I recommend either keeping it or replacing it with a different one.  One of my favorite eyepieces is a 26 mm Televue Plossl (yes, a Plossl) that is quite sharp and clear and has a wide FOV similar to the 30 mm but a higher magnification - and for an AD10 that seems to be one of it's sweet spots.  

 

Also, what you can see will depend on the eyepiece quality....  There is a world of difference between most Plossls and a Nagler or a Lumicron.  My best eyepiece is a gifted Lumicron 26 mm that is incredibly tack sharp and incredibly clear - thing doesn't even fit in my already full accessory case so unfortunately it usually gets forgotten in the house.  

 

Good luck on your next observing endeavor!

[severencir]

Yea I really like the Telrad but no so much of a fan for the mount. I 3D printed an adapter that lets me mount it onto a standard wedge.

 

I am struggling using my telrad near zenith. I mounted it below my finder scope and focuser because anywhere else was just awkward for normal operation. I really need to do something like this to help me. Thank you very much for the inspiration

[vintageair]

I am struggling using my telrad near zenith. I mounted it below my finder scope and focuser because anywhere else was just awkward for normal operation. I really need to do something like this to help me. Thank you very much for the inspiration

If you have a 3D printer or know a friend with one here is a link to the files for the one I made. You have to buy some thumbscrews and a couple of aluminum rods but they're cheap.

 

Telrad wedge mount

[severencir]

If you have a 3D printer or know a friend with one here is a link to the files for the one I made. You have to buy some thumbscrews and a couple of aluminum rods but they're cheap.

Telrad wedge mount

Thank you very much.

Is the dovetail expander thing 3d printed too? If not, where could i find one

Edit: Never mind. it was difficult to figure out what to search for, but i figured it out, thanks!

Edited by severencir, 12 June 2025 - 10:04 PM.

[Kefka1138]

Welcome to CN!!

 

 

 

Thank you for sharing your story. I'm still in the early days of exploring the night sky, compared to some of our peers in the community. So I can relate to the excitement. 

 

 

 

I would echo the benefits of a Telrad. It's an amazing tool. I use it as my primary guider. Once you get your footing, take a look at the PiFinder. It's made navigating the night sky a breeze. I use it to blind hop on chart-mode and observe every bubble in my path. So fun. 

 

 

 

Lastly, this community is awesome. Reading the wealth of knowledge found in searching discussions over the years here is almost as fun as observing. Enjoy!

[severencir]

So... it has been a while because of various factors including overtime making me exhausted, constant weather, getting a new good girl, and some other factors. I did however stay busy. On days that i wasn't too exhausted but i couldn't really get out, i did a few minor modifications. Tonight i was able to take advantage of these mods. I managed to get to a new site that was farther from bright street lights about another 200 yards farther than my usual spot, and holy heck it was so much better. After adjusting my eyes, i was able to see the milky way as a dim cloud across the sky very clearly rather than just as a faint "it's kind of there somewhere." It was evident enough that i could use it to find things. I decided to revisit a few things i was familiar with and then check out some new stuff. I was easily able to see m81 and m82 with direct vision. m31 was far larger and brighter than the previous attempts (though it was also higher on the horizon), and i was able to see m27 very clearly, and even could see some detail with averted vision. the only problem with this site was that it was on grass next to a farm field, so bugs and humidity were a problem, and so was rotating on the azimuth axis for a reason that will become clear soon.

Now for the modifications. The first several sessions showed me many things that were frustrating about using the scope, and now many of them are less frustrating or completely resolved.

 

For starters, i no longer need a screw driver for collimation.
I also made a dew heater strap for my finder out of self fusing silicone tape and nichrome wire. I cut part of an old wool sock out of it for some insulation. I very much intend to make more heaters given that my focuser stayed usable all night, but i had to keep swapping out my eyepieces and my telrad was basically unusable. I also power the strap through a usb LED pwm dimmer to be able to control it's output.
I got a 5v to 12v boost converter cable to be able to power my fan from the 20k mAh battery pack i got for this too
The telrad and finder scope are now both mounted into the dovetail thanks to vintageair. and this new position is much easier to use the telrad in.
I also replaced the little metal eyepiece holder with a couple boxes designed for holding trading cards and some polyethylene foam for the eyepiece box. I put some magnets up as well so i can hold the lids up or have them close as needed.
My dobsonian base is now wheeled to not only allow me to move it farther easier, but also do everything in one trip. The build handles rolling up and down stairs and over grass great. The only concerns i have are that on grass, it likes to wobble a bit, but i think that's mostly because of how narrow the wheels are. i may get a longer aluminum 2x4 and mount them farther apart in the future. I am also concerned about the L brackets i used as they are bending under the stress, so i have decided to just get a couple 2x2 1/8 inch aluminum L bars to replace it, and allow my handle to extend out more. The wheels only having about a 0.5 inch clearance from the ground means that grass is not an easy place to set the scope in the future.

I basically had zero experience in any of this before doing anything. I just spent days researching things until i felt confident i could pull it off, and it seems that, with some adjustments, everything works great.
 

Album: AD8 Modifications

5 images

0 comments

Edited by severencir, 27 June 2025 - 02:25 AM.

[MikeTahtib]

The boxes look great, and should help keep eyepieces dew free.  Another thing you can do to help them is to put a chemical handwarmer in the box.  You can get these at camping stores like REI.  Telrads are tough to keep dew-free, but the sight window is glass, so can withstand wiping clear without scratching.  I recently added some resistors around the edge of mine to heat up the glass, but haven't been able to do much observing due to weather, work etc.  Someone here posted his design for putting a fan on the side of the Telrad to blow air in, and out through some holes underneath the window.  He also added some resistors to the fan to heat the air as it came in.  It looked quite impressive.

[3C286]

Thank you very much.

Is the dovetail expander thing 3d printed too? If not, where could i find one

Edit: Never mind. it was difficult to figure out what to search for, but i figured it out, thanks!

I like the Telrad mount you printed that I see in your album. It's a really good idea to mount it sticking forward of the end of the tube. I might give this a go.

 

Thanks and do continue to update us on your progress and interesting mods .

 

Tak

[Dave Mitsky]

Using higher magnifications can be very useful on a number of deep sky objects, as Tony mentioned.  This largely depends upon the type, size, and magnitude of object in question.  The reason that this works is that our eyes can detect faint objects more readily when they are made larger.

Magnification can help you see detail in faint objects, like galaxies and nebulae, when viewed through your telescope. In my book Visual Astronomy of the Deep Sky, I show how the eye is more sensitive to fainter, lower contrast objects when they appear larger to your eye. As you increase the magnification of your telescope, an object increases in apparent size in the eyepiece in proportion to the magnification. But the surface brightness decreases because the light is spread out over a larger area. You can win up to a point.

https://clarkvision....-mag/index.html
 

[severencir]

The boxes look great, and should help keep eyepieces dew free.  Another thing you can do to help them is to put a chemical handwarmer in the box.  You can get these at camping stores like REI.  Telrads are tough to keep dew-free, but the sight window is glass, so can withstand wiping clear without scratching.  I recently added some resistors around the edge of mine to heat up the glass, but haven't been able to do much observing due to weather, work etc.  Someone here posted his design for putting a fan on the side of the Telrad to blow air in, and out through some holes underneath the window.  He also added some resistors to the fan to heat the air as it came in.  It looked quite impressive.

Thanks. I still have plenty of nichrome and was planning to make the top box electrically heated and use the bottom for non-eyepieces like filters, laser collimator, extension tube etc. I was also planning on possibly wrapping the outside of the telrad glass in nichrome possibly too.

Edited by severencir, 28 June 2025 - 11:44 PM.

[severencir]

I like the Telrad mount you printed that I see in your album. It's a really good idea to mount it sticking forward of the end of the tube. I might give this a go.

 

Thanks and do continue to update us on your progress and interesting mods .

 

Tak

I actually had half a mind to get longer rods and stick it out farther too. I wish the glass was mounted the opposite way so it sat farther forward, but i imagine it was designed for non-newtonians.

Edited by severencir, 28 June 2025 - 11:57 PM.