PeterStudz

26 minutes ago, wookie1965 said:

This is shifting quite a bit the whole donut out so definitely need something. 

OK, that doesn’t sound right!

Back in February @CraigT82 mentioned a new iOS app for live stacking called AstroShader. See…

https://stargazerslounge.com/topic/406419-ios-live-stacking-app-astroshader/

Although unplanned and an after thought, I tried using it a couple of nights ago. I don’t know about you but for me this spring in Southampton has had so many cloudy nights that I’ve hardly been out. But just before bed, noticing that the sky was clear and although a school night I decided to have a ‘short’ (it rarely turns out that way) session on M13, M57 & M27. Bright enough in my light polluted Bortle 7 and one after the other swing their way higher into my “darker” patch of sky late at night & into the early hours.

Getting my Skywatcher 200p Dob out to cool I left my EQ platform inside as I wanted to be quick-ish and simple. M13 first which looked OK but I’ve seen it better. Not helped by not quite being high enough and probably not quite completely dark. Then I remember the AstroShader app and decided to give it a go. 

On M13 I struggled to get the alignment to work. Sometimes it would fail completely (just resulting in a blurred image) or trailing stars. Interestingly, by playing around with camera options, I could get something reasonable in the live view. The image below is a screen snap shot of the front interface. You can clearly make out M13 and if you look closely, the beginnings of the propeller. Remember this is in Bortle 7 and just a screen shot - no image capture, stacking etc. The image on the actual live screen was better. Kind of an EAA or whatever it’s called!

Not wanting to faff about trying to get alignment to work I moved onto M57. I haven’t seen that since last year which made it nice. Here I managed to get alignment to work with just slight star trailing and here’s the result. Remember this is untracked and in Bortle 7. For a first attempt with the app, not really knowing what I was doing and (for me) first capture of M57, I think that it shows promise. It’s rather “widefield” but this was only a test.

First impressions. The app is good at dealing with light pollution. Something I struggle with when doing single shots. The editing section of the app is useful and decent. I found that I didn’t really need any other editing app. Alignment can be hit and miss. I believe it needs some bright-ish stars in the FOV. However, after I used the app I noticed a “strong” option in the apps alignment settings! Will try that next time. Using my EQ platform I can get up to 30 sec exposures without star trailing. So must try and use the app with that. 

Skywatcher 200p manual DOB, iPhone 14 Pro with basic no-brand smartphone adapter, BST StarGuider 25mm. All editing on the phone using AstroShader and finished off in LightRoom. 

6 minutes ago, bosun21 said:

Same here 🙄.

If you want something smaller I can do a swap 😀

Yes, as @neil phillips says it’ll possibly shift a little and that’s not a bad thing - good point. After a while you get familiar with that and know what’s acceptable.

When I first had my primary mirror out I put it back in with the clips too loose. After collimating and playing “chase the donut” for a good 45 mins I realised what was going on. 

13 minutes ago, Mike Q said:

You can't even really make that comparison because the two scopes arent exactly the same.  If i end up doing it i will probably just paint the area opposite the focuser first and see what that does.  Plus, and this may be a non-issue, i don't like the thought of a fuzzy material possibly shedding onto my primary.  

I’ve spend a massive amount of time on the planets before and after. Literally every opportunity (my daughter is a fan). Something I’ve done - flocking and/or the painting - has made a difference.

I flocked my OTA 16 months ago. I’ve had the primary out recently. In that time there’s been no shedding of fibres onto my primary. Although I had a dead fly on my primary - very annoying! 

42 minutes ago, Mike Q said:

I will be pulling my mirror for cleaning eventually, i may consider flocking it at that time.  I know one guy that has done it, he isnt convinced that doing the whole tube was needed.  

The only way to be sure would be to compare the same telescopes (one fully flocked the other not) side by side on the same night. As the cost difference was minimal I decided to do the whole lot. But I also flocked the inside of the draw tube, painted the outside of the draw tube, painted the back & edge of the secondary, replaced bolts & nuts with mat black versions. 

For DSO I don’t think it makes much if any noticeable improvement. But for bright & low contrast observations like the planets it certainly does. The difference on Jupiter and especially Mars, where you are looking for subtle differences in colour contrast was very obvious. And of course I painted and flocked at the same time so hard to know exactly what’s making the improvements.

The primary cell of my Skywatcher 8” Dob has rubber grommets in place of springs plus locking screws. I’ve heard a few people moan about these grommets (why aren't they springs, it’s just cheap, that kind of thing) but I haven’t found them to be a problem and they work for me.

But at first I struggled to get these to lock the primary in a satisfactory manner. Then, someone on here, can’t remember who it was, mentioned using the locking screws as fine adjustment just as you are getting to the locking stage. If you aren’t careful locking down the locking screws can move the primary a little which is frustrating.

In order to lock the primary the trick here is to move the locking screws just so they “touch” the primary. Then slightly adjust adjust the associated collimating screw. Go back and forth between each screw until everything is tight, but not too tight. The screws operate together in a kind of push/pull fashion. Once I understood this and got the knack - issues solved.

Now, I check the collimation every session and I last made adjustments over a year ago. But I haven’t needed ti adjust anything at all. Sure, I’m only moving the telescope from house to back garden but the primary is properly locked. And no springs required. Proper springs could be ‘better’ but it works well so why bother.

I also have a small Skywatcher 4.5” reflector. Now this does have springs and (more importantly) proper ‘Bobs Knobs’ type thumb screws on the primary cell. Why the ‘cheap’ small reflector includes these but the 8” doesn’t is a bit of a mystery. Even with the springs I followed the same procedure to lock the primary as I do on the 8”. Last summer I took this telescope on an aircraft to a dark site. After the 4 hrs in a car (2 hours on winding mountain roads), going through customs, 4 hrs in a an aircraft, dragging the case + telescope on cobbled streets, 35 mins in a ferry… I was very surprised to find the collimation hadn’t budged and was still spot on. Same with the return journey where I wasn’t as careful. Of course this is a small telescope with a small mirror but even so.

15 minutes ago, Mr Spock said:

Same here - a full sized bearing. That and strengthening the base has given me a scope that is a joy to use. 

I need to flock it too, but the size of the tube is putting me off 

I completely flocked my SkyWatcher 8” Dob. But I would have thought that bigger would be easier. For my 8” I found it a bit “tight”. Flexible wrist are a bonus, but even so I got wrist pain doing it

However, definitely worth the effort and overall it was far easier than I was led to believe! 

1 hour ago, Mr Spock said:

Interesting how people's conditions differ. I never get dew - probably because I'm on a hillside.

I almost always slap a dew shield on anyway. Even without dew it does a grand job of keeping out stray light. And for low contrast work, eg the plants, there’s a slight but significant difference. 

I really should get out to a dark or darker location. The New Forest is on my doorstep and I have tried, just taking binoculars out, to a few. My daughter likes to observe too but with just the two of us  and after a short while she does start to feel uncomfortable in these places. A small group and there wouldn’t be a problem. 

It also reminds me of our holiday in a remote part of Southern Crete. We’d taken a  small telescope and the sky was wonderful  - Bortle 1-2 - with no moon. Although in order to get away from the village lights you needed a 15 min walk into the hills. Again, Alice wasn’t comfortable for any real length of time in total darkness but we managed. 

However, on one evening & as we were getting the telescope ready, there was rifle fire out in the hills. And it was close to where we were staying. Went on for about 1.5 hrs. Needles to say that even when whoever it was finished their shooting we did not go out! 

As a beginner dew issues were something that took me by total surprise. It didn’t seem to be mentioned (might have missed something) in any of the beginner guides and articles that I read and I read a lot. First time I encountered dew I thought it was atmospheric fog

I have reflectors but I’ve found that decent dew shields (unheated) are enough to keep dew at bay - so far - although might have been lucky. And I’ve done all nighters where I’ve left the OTA out all night. 

Prevention is better than cure. The first sign that there could be problems is dew on the finder. I have a finder dew shield but if I leave the viewing/eye end uncapped that can dew up. So always cap when not in use. 

For eyepieces I have a jacket with a large front pocket. There’s enough heat in there to prevent dew on my eyepieces, so when not in use they always go there. 

6 minutes ago, Leo S said:

Not looking even slightly clear here tonight sadly, but I did have a go at the ISS a few nights back (100523 - 03:30 UT) while it was clear.

7D II + EF 800mm - 1/2500s @ 5.6 (ISO 640) - Wimberly gimbal head + Gitzo 1325

Nice capture!

Not looking at all clear tonight here in Southampton. But it is looking clear tomorrow (Saturday night the 13th May) when, as far as I can tell, there should be 4 visible passes. 

I never bother with those Bluetooth things. If you have an Apple Watch like I do then that works very well as a camera remote.

On my iPhone I’ve also got a Voice Control (under Accessibility) setup for my shutter button. Handy as this means you can be completely hands free. There’s details on the internet of how to do it. Like here…

https://youtu.be/rJI38Rmjfc8

I sometimes use a PushTo system which I find really useful. I also want to learn how to star-hop, well, be able find my way around the sky unaided. I’ve found that the  PushTo has help me here. Eg I find it reassuring that if I struggle to find a target I can use PushTo. And even when I’ve used PushTo I’ll randomly “nudge” my Dob off target and try and find my way back unaided. My daughter actually enjoys that as a “game” and so is learning to find her way about the sky without knowing.

And Alice being still 11 yrs old can easily get bored or frustrated with star-hopping. Some sort of GOTO or PushTo is a really big bonus here. I also find that kids like using the tech which helps with the overall experience. 

Yes, I do that with an iPhone app called “PS Align Pro” that includes a PushTo feature. You need to align it to at least one known target in the sky and off you go. Some recent discussion of it here towards the end of the thread…

There’s also a web based app called AstroHooper, although I’ve never used it….

https://www.cloudynights.com/topic/800486-astrohopper-new-name-for-navigation-app-aka-skyhopper/
 

When I made the base for my Dob I designed it in such a way that, if I wanted, I could experiment with bearing materials relatively easily. Personally I prefer the traditional laminate/sheet running over PTFE pads. For the AZ bearing I initially settled on an ABS textured sheet running over the pads. This worked well with (being very critical) just a small amount of stiction at very high magnification (somewhere where I don’t often go).  Mind, I can have a tendency to be overly critical.

However, far too many wet, cloudy days/nights and coming across this material by pure chance changed my mind. I do like to experiment anyway - as long as it doesn’t cost much! Haven’t a clue if anyone has tried it before but the material looks the part and is often called “stucco embossed aluminium sheet”. I purchased a 500mm x 500mm sheet (my Dob ground board is 520mm so near enough) from a local supplier which of course meant no postage. It’s thin at .4mm thick and anodised gold. The cost was £13.49 from…

https://hardware-warehouse.co.uk/Embossed-Textured-Anodised-Aluminium-500mm-500mm-0.4mm

But similar is widely available and  not expensive, Eg eBay…

https://www.ebay.co.uk/itm/302206497370?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=yc6KhDB0Qom&sssrc=2349624&ssuid=I8jCpZsmREe&var=601049597017&widget_ver=artemis&media=COPY

I chose this type simply because it’s local. The sheet is thin, easy to cut with tin snips (old scissors would do the job) and could be shaped to altitude trunnions by hand.

The picture is after I cut mine to shape. I just tacked it onto my AZ base with small wood screws. I’ve tested it several times now and even at 375x (it’s a rare night when I can go to that power with my 200p) on Venus and initial impressions are great. Starts smooth, has a nice weight, no roughness, moves smooth and immediately stays where you put it - eg no overshoot. It’s fab! Will see how it performs over time. Eg previously, with other materials, there would be a slight change in performance when very cold, lots of dew etc. Will the anodised surface wear? If it does will it make a difference? We shall see.

This started off with a late afternoon look at the sun in white light. Some fine looking sunspots! Here, in Southampton, there’s been so many cloudy days and nights for what seems like an age. And the forecast wasn’t great, but the hope was that I could carry on into the night after a break for dinner.

At about 4:45pm I decided to try and find Venus even though it was still daylight. I used the PushTo feature of an iPhone app - PS Align Pro - which had Venus in a low power 25mm eyepiece with ease. At this time Venus was quite high in the sky. And I could easily make out the phase. Played around with eyepieces but as it was daytime there was no need to use a filter to tone down brightness. At around 5pm I noticed cloud rolling in and decided to take a short iPhone video. I did some initial processing of the video while still at the telescope which was nice. Then went back inside hoping the cloud would clear. Sadly It didn’t

Video taken was around 10 sec - 4K at 60fps with stock camera app, iPhone 14 Pro on a basic smartphone adapter. Skywatcher 200p manual Dob. BST StarGuider 5mm. Stacked on the phone with the VideoStack app. Cropped and processed on the phone using WaveletCam and Lightroom. For a change and as it was daytime, I kept a blue background. Something that the “processing” didn’t like but it worked in the end. Also left it in the same position as seen at the eyepiece.

Towards sunset this caused a bit of interest during our street party in Southampton on the 7th May. A 22-degree sun halo plus an upper tangent arc. I had to look it up! And off to the side an associated supralateral arc which looked like a rainbow. And I had to check for any showers on rain radar just to be sure. These are simple smartphone snaps.

Dob on the street for some classic Dobsonian “Sidewalk Astronomy”. Clouds cleared enough this afternoon in Southampton to do a little solar demo for our Coronation street party. 

On 03/05/2023 at 19:15, cimh said:

First post here for several years! That sounds v interesting - so does the app help you to point the scope? - if so what a clever idea. I have had my skywatcher heritage 150mm dobsonian for just a couple of weeks and it can take time to find very feint objects. eg last night with the moon up and light pollution it was taking me ages to find the beehive cluster. I could see it instantly in my binoculars but I couldn't see it with my naked eye so the red dot finder was no good I could find it eventually but more by luck than judgement. At times like that an app like this could be great - (It could also save me a cricked neck when trying to point at things high up in the sky).

 

 

 

Yes, that’s basically it. PS Align Pro has a feature within it that will add PushTo capability to a telescope when using a compatible smartphone. I think that it’s just available for iPhone. You need to strap your phone to your OTA like shown in my picture above. I have a phone adapter for a tripod that’;s bolted to my 200p Dob. Out of interest, the first time I tested it I simply struck the phone to the steel tube of my 200p by using the built-in MagSafe magnets on the back of my then iPhone 12. Surprisingly the damn great magnets on the back of the phone and in the case I was using, did not hamper the way it worked at all. Obviously not very secure but enough to get the PushTo feature working.

It does require that the long axis of the phone is parallel to the optical axis of the telescope, but it doesn’t need to be extremely accurate. And there’s no need to level anything or point anything north. Smartphones aren’t accurate enough on their own. With PS Align Pro you need to align to at least one known target (eg a bright star) and “Sync To Target". PS Align Pro will calculate and apply an offset or error. Ideally you want to sync-to 3 known targets but I often get away with just one and take it from there. Eg the Beehive Cluster earlier in the year… I’m in Bortle 7 so it’s only on rare occasions when I can see it naked eye. But I can see it in my 9x50 RACI finder. By locating Betelgeuse in my low powered eyepiece (an easy task) and syncing to it using the app I could then push-to the Beehive and it would be in my RACI. But for greater accuracy if I sync to 2-3 known bright stars the Beehive would then be in the FOV of a low power eyepiece. From the Beehive I could then push-to other targets, eg the galaxy M81, and it would be in the FOV of my low power eyepiece. A little nudge and there is M82. 

I found the app intuitive and never had to read a guide/manual. It includes a database of targets in the sky at the time you are observing. There’s also a host of filters, inc types of target,  brightness, distance from horizon, size, sorting, distance from a specific sky location.

Now, I do like to sky-hop and learn/find my own way around the sky. But the knowledge that if I get confused I can quickly locate a target is reassuring. Also been useful having a daughter who can be impatient (like most kids) with a beginner like me to star-hop. I’ve also used it to find planets during daylight. Eg back at the end of January my daughter had some friends over. We’d been looking at the sun in white light and as they were leaving at 5pm I decided to have a look and using the app see if we could find Jupiter. It was surprisingly successfully, seeing was very good and we could even clearly see the GRS despite contrast being a bit washed out in the daylight. The kids were really impressed that looking up at the sky there seemed to be nothing but in the telescope there was Jupiter with its banding & spot. Plus, as it got a bit darker, the moons slowly came into view. A lot of fun!

If you search the iPhone App Store for “PS Align Pro” you should find it. You do need the Pro version. Make sure you include a space after “PS “, otherwise the search can fail to find it. Or use the link…

https://apps.apple.com/gb/app/polar-scope-align-pro/id970161373

I use the PushTo feature in an iPhone app called PSAlign Pro. It cost (at the time £2.99). After aligning to a know objects(s) it’ll put a target within the FOV of my 25mm eyepiece every time. Something like Starsense might be better but you’d need to purchase a “cheap” telescope and as PSAlign Pro just works I can’t see the point! I’ve also used it, aligning to the sun with a white light filter, to locate the planets - Venus, Mars, Jupiter & Saturn in complete daylight which has been very rewarding and fun. 

I believe that  @Stu has one of these. And possibly @Ratlet. But apologies if I’m wrong!

Yes, the moon is looking brilliant. 

I also had a little look at Mars. It’s obviously very small but there’s an unmistakable little dot of an ice cap at the North Pole. Can just make out some albedo features to the south and around the North Pole but that ice cap glows. Looks very different to the North Polar Hood. 

Had a little late afternoon/early evening session here in Southampton. Clouds, at times around 50/50, coming and going so far from ideal. 

Started off with the sun in white light, then onto Venus, followed by the moon. All in daylight. At the moment Venus has practically the same phase as the moon. Seeing surprising good. I could get Venus up to 300x in my 200p Dob and it still looked reasonably sharp. The moon also looking good despite the lack of contrast in daylight.

Had a break to go and get fish & chips. Hopefully out later if it’s still clear. Although I have to get up early so can’t spend too long. 

On my first telescope, a small skywatcher reflector, I had an issue collimating - every time I move the OTA it would go out a bit. As a beginner it took me several months to work out what was going on.

Eventually I found that a couple of primary mirror clips were not done up properly, so much so that they would physically rattle around, causing the primary to move in its cell. Of course it’s a fine line between too tight & too loose.