DaveL59

I think EP choice will also come down to how easy it'll be to track objects at high mag with the scope. I don't know that model but the NG I have is without slo-mo controls and it is quite difficult to stay on target given the movement isn't as smooth as I'd like. But then I rarely use it as I prefer the EQ setups I have for more than a quick squint  Did make me think tho if its possible to retro-fit something as the original intention was as an entry setup for my daughter+grandaughter and I think they'd soon get frustrated at anything more than low power viewing. I did add an RDF and get a 20-something and 6.3mm plossl set to improve the viewing use tho as the stock ones were pretty poor.

now I'm home and looking at the EP view you posted, I wonder if your secondary is tilted correctly so that it is giving a full view of the primary. Or perhaps its not far enough under the focuser/too far. Tho how you'd adjust the lateral position of the secondary in your case isn't clear as on my mini 76/350 it has 4 screws as per the pic. The outer 3 set the tilt and the central one locks the setting, but the combo can be adjusted to move the secondary further in/out of the OTA. I replaced the original screws in mine so I could get the secondary placed better, seems a common issue on the NG and some others.

Ideally you'd want to:

1. Centre (or offset as appropriate) the secondary in the OTA aperture
2. Centre the secondary under the focuser tube
3. Adjust secondary tilt so you can see the full primary (and clips)
4. Adjust primary 

I use a cheshire to fiddle with mine, don't have a collimation cap and never got round to buying a laser unit but I've managed fine so far. It's fiddly and requires patience for sure especially the first few times. I usually do adjustments in the day then check against a suitable target and later if the sky is ever clear enough will verify and tweak if needed.

The focuser tube shouldn't obstruct the view of the primary even when racked all the way in (when looking down the focuser tube), it'll only obstruct the light path to the primary from the target and likely wouldn't be too far into the OTA when focused with a regular eyepiece.

one question and tbh I've no idea what the right answer is for your scope. The secondary position/offset looks different in the pics where one shows much more of the  screw thread than the other. Is the secondary central in the OTA on these or slightly offset toward the focuser side?

Someone with one of these may be able to answer that one, as that may be affecting your results.

ah, you're looking for it extending down into the tube hence affecting the light path to the primary, rather than obstructing the secondary  

as a thought, the focuser isn't down in the light path is it? as that'll add an obstruction that might be contributing to the 2/3 defocused circle.

same site sells a lead that'd connect to the PSU with bare wire ends that you can attach to the camera, ideally by adding ring terminals. If you're planning on getting a goto mount that'll also use 12v then you might be better to get a higher output PSU than can be dual purposed using a Y-splitter to run the mount and the camera.

the NatGeographic 76/350 is the same setup with the primary fixed and no collimation screws, as Alan suggests one way is to extend the fixing screw holes and tweak that way. With time and a lot of patience you might be able to shim the primary till the alignment is better and then secure it in position, so avoiding extending the screw holes. Have you tried refitting the mirror after rotating the carrier and see if that corrects things, woth trying it in each orientation before starting any real surgery on the OTA etc.

You can also find that the secondary isn't aligned well with the focuser as in too far in/out of the OTA. Once you have it as good as you can get it, the tiny scope performs pretty well really.

any info on their site regarding any other ports used and if tcp/udp? Could be it needs a bit more opening than just the one port.

As to powerline, they are better these days if using the MIMO types tho a huge amount depends on the mains wiring, crossing the consumer unit, electrical noise from things like LED bulbs etc. Also never mix different spec ratings or you slow the entire network to the slowest type on the grid. I run AV1300's and they hold up reliably giving 450-800mbps, tho you do see occasional stalls on the remote CCTV camera feeds. I have the PLAs set for streaming QOS and am running trunked vlan's over them. I've also read that some go sleep the ports if no apparent traffic, which you can work around by running occasional pings to devices the other side. Yeah you've a connection so shouldn't happen, but seems it can. My LAN switches I've turned off green mode too for the same reason.

so some daytime testing, TV Aerial only aprox 100m away. Focus is a bit tricky with winds shifting everything around outside even with the 130 inside the conservatory. There's a few trees further out, say 200-250m again swaying about wildly but managed to focus. I note the in-focus range left is approx 0.5 inch and moving from aerial to trees I had to shift almost 0.5 inch inward, so perhaps the 130 might struggle to achieve focus on moon etc. I'd guess the TAL100RS would fair better as it has a lot of range on the focuser. I did have a brief try for the moon night before last, but just as I was getting somewhere the clouds took over and it disappeared altogether.

Still, this little old cctv module just might get me started at low cost and then I can decide if I want to save some pennies for something better later on. Nice thing is the ability to image flip in camera settings so things are the right way up  

Methinks a focal reducer might be useful to add tho, 0.5x perhaps?

I had considered getting the WiFi add-on for the EQ5 to save having to mess with date/time and location settings if I were to set up elsewhere. Shame they don't just build that functionality in but then it'd bump the cost and be something else to fail or cause frustration. Besides, the new job barely covers my costs so can't really justify that for the moment.

worth trying it in the day and get accustomed to the controls, assuming you've not done that already. Doesn't necessarily have to be perfectly polar aligned and using a sky map app you should get an idea what stars might be up and approx where to see if it slews reasonably to targets it wants to align to. If that works then tell it to go to a target  and see if it roughly gets there. You can check with your phone and app for this, if you can rig a way to hold the phone on the mount/OTA so its aiming along the scope then hopefully result should tally.

Don't forget if you are making an adjust to centre a star during alignment to make the last to moves as up and right before you save it and move to the next.

Oh - and polar aligner pro could help you getting the mount aligned in the day too, might make that step a bit easier.

from reading I did some time ago, best to normalise the batteries before hooking them together, so there's minimal voltage difference in which case you shouldn't get any arcs/sparks. Are you gonna use a controller between the panel and batteries?

do you get a light image with the camera out of the scope and just pointing toward a lit area, a window or white wall for example?

should give a flat white image on the screen. If that's not working reliably then there may be an issue with the unit or perhaps the gain settings, I assume you're using sharpcap to capture the video? I noted that you can set gain up to a point then thereafter more gain meant a dark image with an un-modded C270. I may well mod it for astro at some stage after my experiment with a IP-CCTV module once I've had a chance to test that one out.

the 130M looks very like the SW130 I have, EQ2 mount and RA motor to track that can be switched for star/planet and runs off 4xD batteries. It's a competent scope tho I've yet to try it for any form of imaging. Eyepieces are OK tho I've a few better ones now so don't really use the originals. I'd double check tho if the mirror is parabolic, not sure it is since it doesn't specifically say tho I don't think it matters as much being a longer OTA version.

Can't comment on the others you list as I've not met those myself  

yeah I'm not expecting great results tbh, still no harm in having a play given it's sat around spare - it was the module I first used for the sky-cam experiments till I got the 5MP module that also has relatively fast slow shutter of 1/10s. None of the CCTV modules really lend themselves to running long exposure unfortunately, but they are at least starvis sensors so with long enough video capture they might give some interesting results for little outlay, time will tell...

so another cheapo experiment hopefully set and ready to try when (IF!) there's actually clear skies, tho I'd like to have a play in daylight first just to confirm focus can be achieved etc. Again using a spare Hik-able CCTV IMX290/291 sensor and webcam nose-piece with IR filter. It'll need 12V power and LAN to work, tho I guess I could also hook to it over WiFi.

Limitations will be the 1/25 slowest shutter more than anything I expect but heck it'll be a free-ish experiment... Just need the moon or planets to play nice when the cloud cover opens up a bit. If it can capture any useful video on one of the tracking mounts to stack then it'll be an OK intro. I can always opt to mess with the Logi-C270 later but I think this sensor may be better than what's in the Logi.

no harm in trying it out and see if its enough before spending extra  

if you're happy to go less wide...

https://www.ebay.co.uk/itm/2-7mm-CS-Mount-Fisheye-Fish-Eye-Ultra-Wide-Angle-GLASS-CCTV-1-3-Lens-F-1-1-4/382826414881

might work ok tho I can't vouch for FOV, this one likely is the best but as noted, expensive
https://www.ebay.co.uk/itm/Fujinon-1-4mm-f-1-8-Fisheye-lens-CS-Mount-DF1-4HB-L1-Ideal-for-All-Sky-Camera/123866962892?hash=item1cd70bdbcc:g:HAkAAOSwDuZdSr43

I'm assuming CS mounting but that's a guess on my part

2 minutes ago, Laurin Dave said:

Hi Nigella..  just finishing one off myself..  it looks remarkably like yours!  I use the AllSkyeEye software, works really well and has loads of features.  I’m using the ZWO lens that came with the camera at the moment, seems ok for now but will be interested to see what lens recommendations are made.  I’ve put a heater in mine, dewed up quite quickly without, I had an unused ZWO Dew heater and it works a treat.

Dave

I guess then that the ZWO doesn't run too warm?

The IP CCTV module I use does so I've never had it dew up so far, only the first effort has had issues because a seal had failed but not got around to getting that apart as yet. If its dewing on the inside a couple silica gel sachets will help a lot too.

easily done, I'll admit I didn't either but luckily didn't make contact. My rig the lens is quite close to the dome itself so its only the top 1/3 that matters in terms of the view. Clear RTV will do ok just take care clamping the dome down. Removal later would need a craft knife under the dome edge probably. Also let it set and air well if poss before fitting the camera/lens to avoid any outgassing affecting the optics. Or try getting an RTV that's ok for optics use.

Re the lens, yeah they ain't cheap, I think Gina has the Fuji one on hers and tbh it's likely the best but are real pricey and IIRC CS mount not M12. I swapped the M12 for CS with switchable IRcut on the 5MP cctv module I'm using just to try a larger glass area but not sure it made a lot of difference. The hard bit is to get a fisheye lens that is F2 or faster that suits the sensor size, sadly there's few good choices and they're more expensive. The one I'm running at the mo is I think 2.1mm F1.8 and it seems to work ok but gives more like 150 degree rather than a full 180, so I run the camera inclined toward SE as that's gonna show a bit more of interest for my location. 

actually thinking about it, if the scratches are light, then brasso might work just as well too

you might be able to polish the scratches out with something like a car headlight refurb kit, but then a new dome probably works out cheaper and won't result in any optical irregularities. Depends if the marks are in the visual line of sight vs the camera lens position. Defo worth taping over the dome next time, perhaps.

What are you planning to seal under the dome edge with? I used a nitrile wide flat washer which seemed to work well on my el-cheapo rig and means the dome is easily removable compared to silicone RTV. You do want to avoid capilliary action drawing water in under the edge tho but don't want the clamping force to be so great as to distort/crack the dome rim. Some stainless washers might help spread the load a little?

As for a lens, I think that's the harder part, what fitment is it, C/CS or M12? 
I guess lens speed is less of an issue given its an astro camera so can run slow exposure, but a decent F1.4-F2 can be pricey and you'd need to match against the sensor size if you want a full-360 with no clipping of 2 edges. I've seen fuji CS lenses come up but they're in the £90+ region. I guess you'd also need a lens with IRcut filter built in or you'll get some odd colour effects in daylight

Enjoy the scope, was after one of those myself a while back but wasn't to be 🙂

the Prinz 660 refractor? Lucky as that's reputed to be a very nice vintage scope.

The filters would be 2 separate round components, one moon and one sun, that would screw into the bottom of the eyepiece as banjaxed has said. best to bin the sun one or at least seal it in a bag labelled "never use!". Not sure if this scope uses the older 0.96-inch eyepieces, in which case it may be hard to source replacements if they are missing, but IIRC you can mod the focuser to work with 1.25-inch EP's which makes obtaining better EP's a lot easier.

almost sounds like its not coming to focus as you should find it'll snap into focus and be able to make out detail. Did it come with any filters, sometimes there's a ND moon filter which may help reduce the brightness if its overpowering your eye.

When you had it in focus in daytime, was it a distant object and how far in/out did you have to crank the focuser to achieve? 
If you were near the end of travel then perhaps there's not enough travel for focus on astro targets with the eyepiece.

If the focuser doesn't have enough in/out travel then it may not manage with just the eyepiece, was it configured for photography use I wonder? Tho I'd have thought modern scopes would have adequate in-travel for photo use without shifting the mirror so I may be well wide of the mark with that train of thought...