JamesF

Regarding the use of 2" diagonals and eyepieces, isn't the baffle tube the limiting factor with larger diameter field stops?  I don't know as whilst I have a 2" SCT diagonal, I don't use it on my 127 Mak.  I feel sure the baffle tube only is only about 30mm diameter though?

James

Just now, Louis D said:

But unless you're in quite dark skies, you won't see much beyond its core.  It's surface brightness just isn't enough to overcome most skyglow.

Oh, certainly.  But if, say, the Moon fills the field of view with a given eyepiece and you can only make out enough of M31 to fill, say, half that, then it gives you a clearer idea of what it is that you're seeing, or if you're trying to work your way from M31 to M32 (which is much further away than you think it would be when you can only see the core of M31 and you're still learning how things look).

James

On 25/08/2021 at 02:23, Louis D said:

Also, try some of the large globular clusters like M13.  Lastly, view some of the brighter planetary nebula like M57.

Absolutely this.  The 127 Mak works very nicely for globs and the brighter planetary nebulae.  It's also good if you make a filter from Baader solar film and use it to view the Sun in white light (but understand all the safety issues before you do this).

James

On 01/08/2021 at 20:44, Zermelo said:

M31 is a very large object,

To expand on this a little, M31 is about 3°x1° whereas the full Moon is about 0.5° in diameter, so if you think about how the Moon appears in any given eyepiece, that gives you some idea of how much of M31 you can see with the same eyepiece.

James

Five or six frames per second is the best this camera can do at full frame size because of the limitations of the USB2 interface.  It should achieve that though, and I'd have thought it would be sufficient for focusing.  What exposure time are you setting in Sharpcap?  Obviously anything more than 0.2s will mean you get even lower frame rates because the exposure time then becomes the limiting factor.

Another thing to consider is what else you might have connected to the same USB bus as the camera.  Bandwidth is shared on each USB bus, so anything else that is taking bandwidth can reduce that available to the camera.

James

One other suggestion I've seen online is to unplug the camera, make sure any drivers for it are deleted (in device manager?) and then install the ASCOM driver before plugging the camera in again.

James

I wonder if SharpCap can use the DirectShow driver?  I think it might be able to.  Could be worth trying to install that?

James

Oooh, ooh!  I could slap whoever did this, actually...

Looking at the photos in the documentation, it looks like the CD is called "Meade SkyCapture".  But SkyCapture is also the name of their own capture application and they may well not be the same thing.

Can you try downloading the top link from this page ("SkyCapture Software Download").  It's possible that you might find the ASCOM drivers in that zip file.

James

1 minute ago, StuartT said:

Unfortunately I don't have the CD (no CD drive in my laptop anyway!) So I am reliant on the web. It's pretty unusual nowadays to have a CD drive I think

Ah, right.  That's not helpful then

James

1 hour ago, StuartT said:

right. I would have done that. Except that Meade doesn't provide camera drivers. I even contacted them and they told me all they have is ASCOM or SkyCapture! Hopeless.

Ah, perhaps I misunderstood from the excerpt of the documentation that was posted.  I thought the CD contained both the ASCOM platform and the ASCOM drivers separately.  My apologies.  Their documentation does appear to be out of date, as the most recent version I can find, here, still seems to suggest that the ASCOM drivers are present, but that's talking about v6.1.

James

5 minutes ago, StuartT said:

I'm pretty confused about this to be honest. Are you saying that the ASCOM platform (of any version) should contain all the drivers it needs, irrespective of where I got it from?

No.  I'd expect that each vendor will supply their own drivers for their cameras.  I think you should try installing the 6.5 platform from the ASCOM site, then go back to the Meade CD, ignore the bit about installing their ASCOM platform and just try installing their ASCOM camera drivers.  I'd hope that process would just find an ASCOM v6 installation on your PC and go ahead with installing their drivers.  If it objects because the ASCOM platform version is not 6.3 that would be quite disappointing

James

2 hours ago, StuartT said:

Problem is I already had ASCOM 6.5 installed from the ASCOM website, but the Meade CD only has ASCOM 6.3. So in order to install the drivers I'd have to downgrade ASCOM, which I guess could cause issues with my mount etc.

Does the driver refuse to install with the 6.5 platform you already have installed then?  I'd kind of hope that all v6 platform releases would be backwards compatible for v6 drivers, but perhaps that's not the case.

James

19 minutes ago, johninderby said:

Just removing the corrector plate is easy and unlikely to affect collimation. Skymax180 but same internal nuts on the dovetail bar. On the 102 the corrector plate cell just unscrews.

Similar situation with the Skywatcher 127 Mak (screw-on cell).  I guess all of them are a very similar design.  I agree that taking the corrector off shouldn't be a major deal if you need to and if you should need to collimate afterwards, whilst I'd say it's not as easy as for a newt, it's hardly a nightmare.  Just takes a bit of patience.  In fact it's just occurred to me that setting the OTA up horizontally on the mount with a camera on a stand a metre or so in front, feeding a view of the front of the OTA back to a screen where you can see it whilst twiddling the collimation screws might be quite helpful as a way of getting things pretty close.  I'll have to try that next time.

In my case however, it's usually the nut behind the OTA that causes most of the trouble.

James

42 minutes ago, Oldfort said:

You may thank us one day.

For example, I was recently able to fix a set of cooking saucepans, of which the rivets holding the handles had failed, becuase of my extensive set of stainless steel fasteners.  I got quite a few brownie points for that.

Oooh, what did you use?  I went with stainless pan-head (of course) allen bolts and domed nuts when one of ours failed because the dishwasher ate the cheap and nasty "metal" the manufacturer used for rivets, but something lower-profile would have been preferable.

James

3 hours ago, wulfrun said:

No it's not just you. However, I tend to just keep quiet...sometimes it's an innocent mistake (or, more annoyingly, an auto-correct induced thing).

I tried, honestly I did.  But every time it appeared on the screen my brain just forced me to look at it.  I don't know why.

James

3 hours ago, Chris said:

Done  Normal brain activity may now resume  

Thank you, Chris.  Much appreciated

James

Could someone take pity on a tired old pedant and remove the greengrocer's apostrophe from the topic title?

It's probably just me, but they make my brain do horrible things

James

Are you sure it's not really woven liquorice?

James

2 minutes ago, StuartT said:

thanks for this sneaky suggestion. I can see the meade dll in SkyCapture, but I can't see any toupcam dlls in Sharpcap.

Well that's that idea blown out of the water then   Perhaps Sharpcap doesn't support the Toupcam cameras (I thought it did), or maybe it picks up the dll from somewhere else.

James

1 minute ago, StuartT said:

'Redbadged' cameras?

Rebadged   Many (most?) of Meade's cameras now appear to be made by Touptek, but are branded as Meade -- similar to Altair, Omegon, Risingcam, some of Orion's cameras and others.  Touptek also produce the capture software which is also rebranded for each vendor.

5 minutes ago, StuartT said:

So I guess what you mean is the fact that SkyCapture can see the camera doesn't mean it's properly installed? Even though it's showing in device manager?

Touptek produce a driver/interface library for each of the vendors of rebadged cameras and SkyCapture probably uses that.  Sharpcap probably could use it too, but I'd guess it doesn't right now, so would have to use Meade's ASCOM driver instead.  I don't really do Windows I'm afraid, so I can't help with that bit.

I've no idea if it would work and I'd actually be a little surprised if it did, but assuming you have no Touptek cameras the hacker in me would be slightly tempted to try finding the meadecam dll(s) included with Skycapture and copying them over the equivalent toupcam dll(s) in Sharpcap to see if it might recognise the camera that way.  I'm fairly certain that approach wouldn't work on MacOS or Linux, but as I said, I don't do Windows: it might be a bit more relaxed about the library changing name.  It might even completely break Sharpcap to the point of needing to reinstall it.

James

SkyCapture will be using Touptek's own interface for the Meade cameras I would imagine.  That seems to be the way it works for all of their other rebadged cameras.

James

11 minutes ago, The Lazy Astronomer said:

Yep, that pretty much exactly matches the amp glow pattern of the 178 sensor.

Agreed.  A dark would make certain, but it's quite a distinctive pattern.  I'm just not sure why the OP never noticed it with the other OTA.  Longer subs now, perhaps?

James

Light scatter from part of the optical train, possibly?  An example image might help to determine the cause.

James

4 hours ago, Gmx76 said:

@Lens cap so all the electronic parts have arrived and i have a question. My Nema 17 motors have come with fairly short (30cm) cables with no connectors, just bare cables. Is this enough length, and do i need to buy a couple of Dupont 4 pin connectors?

I used smaller motors (NEMA14, I think) for my conversion and the leads were even shorter, so I got some 4P4C (commonly called RJ11, IIRC) connectors and fixed the sockets to the motor mounting brackets with the motor wires soldered to the pins.  Then separate cables run from the control unit to these sockets.  I have a nagging feeling that the cables might actually just be ST4 guide cables that I had lying about.  I put some heatshrink over the four wires for each motor, too, just to keep them together.  It's not pretty, but it does the job.

James

On 03/08/2021 at 16:32, lenscap said:

On the EQ3-2 the RA driven pulley will foul the RA clutch lever unless you do something to avoid it. I cut away part of the lever which you can just see in the bottom left this pic.

I managed to avoid this with my EQ3-2 conversion (which is uses AstroEQ, but the motor side of things is pretty much the same, but the drive belt runs right on he inside edge of the pulley (slightly different from yours, in that it doesn't have the side plates -- I perhaps used a different type of belt/pulley).  Then in the end I got nervous and 3d-printed a new lever with a thinned down top edge to ensure clearance

James