Webcam imaging help!

[milkyjoe]

OK. So all my bits and bobs arrived yesterday for my spc900nc webcam I purchased from TopHouse (thanks again ;-)) including my revelation ir/uv cut filer, a ra motor drive for my eq1 mount, and of course, the nose piece (low profile version - £13.99 from scopesnskies.com).

I'd noticed the weather forecast for last night was looking good, so I decided I would have a go at taking some images; I downloaded the SharpCap program, setup the webcam: attached the noise piece and the ir filter and I had a quick read through the webcam imaging primer in the help section of this site. All was looking OK so I loaded SharpCap and Registax and took the scope, laptop and webcam outside after attaching the RA motor drive to the mount.

Once outside, I quickly aligned the scope to polaris in the usual fashion, pointing the scope to North, and had a quick sip of a nice cuppa... aaah!

My first problem came when I attempted to align the scope to Jupiter using the coords referenced from Stellarium... RA: 21h 34m (approx) DEC: -1 deg; OK I thought, unlock the RA and DEC lock knobs and move the scope into position, but on trying this, the motor drive was blocking the path! Yes, I know I probably should attached the MD after I've aligned the scope, but seems a bit silly if I keep having to take it off and put it back on each time I want to look at an object; I'm still trying to get to grips with the coords system as it is and aligning my scope in this way will become a bit of a nuisance!

Quick question: with my scope aligned to Polaris and pointing North, if one wanted to observe Jupiter (in the south-east sky; where else would it be! ), which way should one turn the scope, left or right, is this in accordance with the RA dial (upper numbers for use in the northern hemisphere (left) and lower numbers for use in the southern hemisphere (right))?

My second problem arose trying to track objects. I began with the obvious choise (as we all do), but because I could not properly align the scope to Juipter, I had to do this manually. I popped in an ep to get Jupiter in the field of view and then popped in the webcam and tried to get Jupiter in focus using the scope's focuser (is this the correct way of doing this because I could not get a sharp image on the screen!?), I then sat down with laptop in hand and proceeded to fiddle about with SharpCap. After a few minutes of 'fiddling about' with the settings, I couldn't see much detail on Jupiter at all (I must have been doing something wrong!? ) so I hit Capture anyway..., it was then I noticed Jupiter was moving even with the MD switched on; it did not seem to be tracking, but I assume this had something to do with the fact that the scope was not aligned correctly?... it did, however, make a very nice loud whirring noise instead!!

In conclusion: after all the buying of components, all the waiting for around, the anticipation and excitement, setting up, messing about with capture software... it was a complete waste of time!!! I am wondering now if I should I invest in a proper GOTO mount or just give up for now?

Any advice, tips and tricks would be most welcome.

Richard.

[Merlin66]

Welcome to the trials and tribulations of imaging!

I see you have a EQ1 mount.. this is very basic but should still allow you to image planets/ moon with the webcam.

Not 100% sure but you shouldn't have to relocate the RA drive motor in normal use. Which drive do you have? Is it connected to the RA shaft correctly? Can you post an image?

Getting the polar axis properly aligned is a PITA at the beginning but certainly gets easier with practise.

Yes, your correct about the dials....but on an EQ1 they're not really accurate enough to work...

Focus the planet in your eyepiece; move the focuser inwards about 10mm and then swap over to the webcam, this should bring you close to the focus. As you say, twiddle the focuser until you get he best image and start recording......

Registax 5 will try and get the best outcome from your AVI....practise, practise, and more practise.

Ken

[Psychobilly]

Also remember that the FOV of these webcams is roughly equivalent to a 6mm EP so targets can quickly drift out of the FOV...

I tend to use a cheap 8-24mm zoom EP which I have made parafocal with the camera to locate objects .. if its lost you can zoom out and re-center...

Peter...

[jgs001]

Also, use slow movements with the focuser, you'll be surprised how quickly the object can slip through focus and out again, and you won't notice... but as has been said, practice, practice, practice...

[Deano6128]

Hi Richard,

Don’t despair, I’ve recently got into a bit of imaging myself and have had exactly the same problems with my eq-1 mount - but there are ways around it.

When lining up your scope with Jupiter, don’t worry about the RA and DEC co-ordinates just rotate your scope until you have Jupiter in view. You can rotate this either right or left, whichever gives you the most clearance from the motor drive.

Next comes the tricky bit – trying to get Jupiter to stay centred in the field of view. If you have the same motor as me, then there is a little dial you can turn to adjust the speed of the motor. I find the easiest thing to do is firstly get the object centred in the eyepiece using a magnification that is similar to that given by the webcam. Then spend 5-10 minutes playing with the speed control to make sure that it stays centred in the view, at least long enough to take a 90 second capture.

You should then be set to start taking your captures; pop the webcam in and use the scope’s focuser to bring the image into focus. If you’re struggling to get the image sharply focussed then I would highly recommend using a Bahtinov mask (there is a mask generator at astrojargon - Bahtinov Focusing Mask Generator: Overview, just print and then cut it out of a piece of cardboard).

Hope some of this helps

Dean

[lukebl]

Also, don't expect the individual frames to took much good. They won't! It's only after stacking in, say, Registax, that they reveal their hidden detail.

I always use a Bahtinov mask to focus very accurately on a bright star, then slew back to Jupiter. You can't really use a Bahtinov mask to focus on anything apart from a stellar object.

[milkyjoe]

Hi Ken,

Thanks for the tip re: using the focuser.

I have the basic eq1 ra motor drive, but I'm at work at the mo so will post a pic later.

Thanks.

[Space Cowboy]

Patience and practice! Considering your scope was not properly aligned you've done well just to get an image on the screen. I started webcaming with the moon i.e at the shallow end ;-) I would also recommend getting a cheap zoom eyepiece, makes it much easier to centre the planet. Once you start adding Barlows your alignment has to be nailed spot on!

[milkyjoe]

Hi Deano6128.

Thanks for the info, I just have a few more questions. See below...

Hi Richard,

Don’t despair, I’ve recently got into a bit of imaging myself and have had exactly the same problems with my eq-1 mount - but there are ways around it.

When lining up your scope with Jupiter, don’t worry about the RA and DEC co-ordinates just rotate your scope until you have Jupiter in view. You can rotate this either right or left, whichever gives you the most clearance from the motor drive.

When you say "rotate your scope until you have Jupiter in view" do you mean rotate on the RA axis or unscrew the knob underneath the mount; the bit that confuses me is when you rotate the scope on the DEC and RA axis, the scope tilts over to the left or right with the counter-weight on the other side; is this what you mean, can you show me using an image of how the scope should look for use with a RA MD if possible?!

Next comes the tricky bit – trying to get Jupiter to stay centred in the field of view. If you have the same motor as me, then there is a little dial you can turn to adjust the speed of the motor. I find the easiest thing to do is firstly get the object centred in the eyepiece using a magnification that is similar to that given by the webcam. Then spend 5-10 minutes playing with the speed control to make sure that it stays centred in the view, at least long enough to take a 90 second capture.

I am aware of the speed setting dial, but even at full speed last night, the scope did not move at all, which is why it was recommended I align the scope first beforehand.

You should then be set to start taking your captures; pop the webcam in and use the scope’s focuser to bring the image into focus. If you’re struggling to get the image sharply focussed then I would highly recommend using a Bahtinov mask (there is a mask generator at astrojargon - Bahtinov Focusing Mask Generator: Overview, just print and then cut it out of a piece of cardboard).

What the heck is a 'bahtinov mask" ??

Hope some of this helps

Dean

Thanks

Richard.

[Deano6128]

Hi Richard,

No worries

When I say rotate your scope I mean rotate about the RA axis, once you've polar aligned your scope don't move the mount head itself. Try the link below which shows animations of how to move an EQ mount to various positions:-

Astronomy Boy: Animated Equatorial Mount Tutorial

If the mount isn't tracking, even when set at full speed, then you need to make sure that the little screw that attaches the drive to the RA axis is screwed down tight on the flat bit of it (might need to rotate the axis when fitting the drive).

A bahtinov mask is a mask that you put on the end of the telescope and when you look through your eyepiece/camera you will be able to see diffraction spikes that help you focus more accurately:-

Bahtinov mask - Wikipedia, the free encyclopedia

Dean

[milkyjoe]

Thanks again for your help Dean.

Just a few more questions (sorry)...

Hi Richard,

No worries

When I say rotate your scope I mean rotate about the RA axis, once you've polar aligned your scope don't move the mount head itself. Try the link below which shows animations of how to move an EQ mount to various positions:-

Astronomy Boy: Animated Equatorial Mount Tutorial

I have a basic understanding of rotating the scope using the RA and DEC axis, but what I find is that after I have polar-aligned my scope, any further coords I attempt to use with the scope do not work, i.e. last night I polar-aligned successfully (values were slightly out but I guess that's down to my basic eq1 mount), but if I used the coords from stellarium for Jupiter, my scope would of ended up pointing at the ground!!

If the mount isn't tracking, even when set at full speed, then you need to make sure that the little screw that attaches the drive to the RA axis is screwed down tight on the flat bit of it (might need to rotate the axis when fitting the drive).

I did indeed make sure the screws were tight, but does the other screw have to be tight as well?

A bahtinov mask is a mask that you put on the end of the telescope and when you look through your eyepiece/camera you will be able to see diffraction spikes that help you focus more accurately:-

Bahtinov mask - Wikipedia, the free encyclopedia

Dean

Thanks Dean.

[themos]

Please ignore the "setting circles", those round dials with numbers printed along the edge. They are simply more trouble than they are worth.

What other screw?

[themos]

If the EQ1 motor is in the way, simply rotate in RA 180 degrees and then rotate in DEC 180 degrees. The counterweight bar should be able to clear the motor housing, if I remember correctly. You may end up with the counterweight bar pointing upwards but that is no problem.

[Merlin66]

Re the RA motor....which other screw?

There's usually a small thumscrew which clamps the motor drive to the RA worm shaft and then there's a sort of tube with a small bar which only clamps/ swings the motor on the mount.....

Maybe a photo is needed??

[milkyjoe]

Re the RA motor....which other screw?

There's usually a small thumscrew which clamps the motor drive to the RA worm shaft and then there's a sort of tube with a small bar which only clamps/ swings the motor on the mount.....

Maybe a photo is needed??

Hi.

The other screw I meant was the one that connects the 'ra worm shaft' as there are only 2 anyway. Should both be quite tight?

I will try and post a pic after work so you can see what I'm on about.

One more thing, is there anyway of supressing the whirring noise from the motor?

Thanks.

[milkyjoe]

Please ignore the "setting circles", those round dials with numbers printed along the edge. They are simply more trouble than they are worth.

What other screw?

Lol, yes, I'm beginning to see that! Maybe you can align your scope more accurately using a better mount?

Thanks.

Richard.

[themos]

You have this one, yes?

One screw goes through that metal bracket and into the altitude adjustment axis of the mount.

The plastic flexible coupling (cylinder shaped) behind the motor housing fits around the RA worm axis end and you then secure the coupling with its integral screw which tightens onto a flat notch of the RA worm axis.

[themos]

For polar alignment with the EQ1, I do this:

Release the RA clutch and rotate until weight bar hangs down as vertically as it can. Tighten RA clutch.

Release DEC clutch and turn scope so that it points as far up as it can. Tighten DEC clutch.

You don't release those clutches until you're done polar aligning.

Loosen the azimuth bolt under the apex of the tripod and rotate the mount (keep the tripod legs fixed) left and right until the scope is pointing to Polaris's bearing. Tighten az bolt. You may already have Polaris in the finder at that point (you have aligned the finder and the scope, right?).

Loosen the altitude clamp and rotate the altitude screw, raising or lowering the mount's polar axis to centre Polaris in the scope view. Tighten the altitude clamp. You are now roughly aligned and you can now loosen the RA/DEC clutches and point your scope where you like.

[milkyjoe]

Yes, that is the one I have, and yes, that is what I did last night, but as mentioned in an earlier post in this thread, my scope did not move when at full-speed!? :-\

Thanks.

[themos]

In general, if an object is east, your scope should be on the western side of the tripod and the weight on the eastern. That arrangement keeps the counterweight low and the scope high.

But there's no reason why you can't swap them over, turning 180 degrees in RA. Ok, so now your scope is pointing at the ground, so rotate it in DEC 180 degrees and it's back to facing the sky.

[themos]

Scope not moving:

First check that the coupling turns when the motor assembly is not connected to the scope. Just let it run for a few minutes. You should be able to see movement after some time.

Secondly, when you slide the coupling over the RA axis end, you must tighten that screw that "bites" on the flat notch of the RA axis.

Thirdly, the RA clutch must be tightened, otherwise the scope will not pick up the rotation.

Fourthly, you must allow some time for any slack in the worm/big-gear contacts to be taken up.

Good luck!

[milkyjoe]

Thanks themos,

Hmm... perhaps I did not let the md run for long enough, I will try again and let you know in due course, but I will still post a pic of the setup later so you can see how I've attached the drive.

I did test it beforehand, and I did see it moving, but very slowly so at least it does appear to be working.

Is there a way to dampen to sound from the motor as it's quite loud?

Thanks

Richard.

[Deano6128]

As has been already stated above, completely ignore the setting circles. So long as you can see Jupiter just point your scope at it and forget about the numbers on the setting circles as you don't need them.

I always tighten the screws pretty well, but make sure when attaching it to the RA worm shaft that you don't push the connector on too far, otherwise the screw doesn't quite line up with the flat notch (resulting in the motor slipping and the mount not tracking).

You can try getting the motor working properly in the daytime. Set it all up and point the telescope at a stationary object, leave the motor on for a bit (as it moves pretty slowly even at full speed) and you should be able to tell if it's working as the object will be moving out of view.

Not much you can do about the noise I'm afraid, but you'll find that when tracking at 1x it's not too noisy

Dean

[themos]

If you take out the motor and connect the RA slow-motion stalk to the RA axis, can you turn the RA axis with it?

[matteboy]

Sorry to butt in on this one but I'm having major problems getting to grips with my EQ1 mount aswell, also polar aligning in the first place. Can some explain how the dials work to me, the lower ones seem to be 0-24 & 24-0 (this one seems to rotate so you can put it where you want, why?) and the upper one 0-90 &back to 0 then back up to 90 & then back to the zero where I started (this one is fixed and you cant move it). I've fixed the same motor as pictured above & now the counter weight keeps bashing into it, so I've moved the counter weight out a bit so the scope isn't balanced spot on. I only use the 'scope for visual but really would like to understand how it works to see if I'm doing something wrong, let me know if I should post this seperately!!!

Matt