stan26

Don't worry you'll get there eventually mate.

Your doing things at 100mph compared to me. I put up my guided project on the forum when I eventually had the necessary equipment and had eventually got it up and running in a functional manner. It may look like I went from un-guided to guided over night, but trust me I didn't! 8:23 pm on the 26th April last year was when I asked my first question on here about guiding the EQ3-2. That was the moment the seed was sown for me, and its taken till now to gain the knowledge and bits to make it happen.

To be honest I wouldn't bother wasting to much time with the LVI. I spent a bit of time reading up on what it can and can't do and I don't think you're going to have any success with it, which is a great pitty.

PHD can have some inconsistent behavior, But I have found that correct balance of the rig and things like making sure the backlash if any has been taken up in the DEC guide direction before the "PHD" button is pressed can eliminate this, after all it is computer software we're talking about, and contrary to popular belief computers generally don't have mood swings etc, it will compute exactly the same from one night to another, it will be physical changes to the mount/scope/orientation that will make things act differently......but that's my opinion.

Stan

Hi Stan and QM, I'm back on for the guide mod! as I mentioned I sold my eq5 mount for 200 the other day, I've just reserved a rig on AstrobuyandSell, and I think I've got a pretty good deal black HEQ5 with f/5 200p plus electric focuser 50mm finder plus red dot and OTA carry case all for 420 pounds! I pick it up after work tomorrow, only about a 2 hour drive which isn't bad with the black HEQ5 I can do the st4 mod and add an ST80 guide scope and I recken the HEQ5 can take that? So my upgrade as cost me 220 pounds and I still have my Antares 80mm frac. Another option would be to sell my Antares and the 200p and this would pay for most of an ED80 I recken, any ideas? oh yes, I like your diagragm Stan you certainly put the effort in on this site

Get in! your well on your way then Chris. That sounds like an amazing deal to me! The ED80 idea sounds good to me. That would make a really nice imaging rig, I'm jealous, wish I could afford an HEQ5 and ED80 That said I do have a £700 lens coming my way (for alot less) in the form of a Canon 200 L prime. I'm taking a step back in terms of focal length and going to concentrate more on widefield in the future. This I think is my preferred format of AP i think. My next step will be to mod another cam. I will then look out for either a TAL100 RS or ED100 to do galaxy and small nebula work, although the subs will be dramatically shorter.

Keep us up to date on the progress Chris!

Stan

Well considering its early days that is one hell of a result!

Just noticed you are using a st102. How much of the fov did m42 take up using the d500? I pre ordered an evostar 102mm OTA for Luna but the supplier couldn't get one.. Seems they only come on mounts. Might have to go for the st instead after seeing this.

Thanks PSY3NTIST.

I have attached single 5min sub of M42 in its original raw format (although this is a resized jpg) so that you can see the FOV and what you'll be up against with the editing. The ST102 is a lovely little scope and brilliant as an intro imaging scope but you'll soon notice the purple halos/ bloated stars/ and also you'll notice that only the stars in and close by to M42 are round the rest of the frame has field curvature and some rotation. These are the main draw backs of the ST's low end optics, and a reason why I crop my images like I do.

Also you'll notice that my framing was a bit off that night, but I was keen to get some guided imaging done and couldn't be arsed to re align the whole thing after finding the guide star on the webcams tiny FOV. The below was taking with the Canon 500D at prime focus, no filters, just a T adapter.

Stan

Thanks QM.

Actually I'm really happy with the way the above picture has come out. Its probably the best image I have posted on here, and no tweaking curves and levels either:D:D:D

Stan

Thanks Stan. Will continue to watch the discussion develop do you have any examples of your guided work online?

Its still early days for me and guiding,but here you can find a pic of my first and only guided imaging effort so far.

http://stargazerslounge.com/diy-astronomer/172953-eq3-2-dec-axis-direct-drive-mod.html

Also there are graph screen shots to show the guiding accuracy. I have only just started getting Osc index of around 0.22 after a bit of tweaking. Some of the subs in the image where pre-tweak where the guiding was OK but not as good, especially in DEC.

And here you can find my original thread on guiding with the EQ3-2, with the first ever guided shot I took when I first linked it all up and hit the guide button for the first time with absolutely no tweaking whatsoever!

http://stargazerslounge.com/imaging-discussion/169572-woohoo-guiding-eq3-2-a.html

HTH

Stan

I have watched this thread with great interest but what kind of resolution will this have? The goto upgrade states Resolution: 0.288 arc second. Not too fussed about the goto but is the extra accuracy worth the extra 200 quid? Eventually I want an eq6 but that's a little out of reach at the minute.

Probably not much help to you question here, but with my tuned EQ3-2 guided with dual axis steppers I manage to get an average PHD feedback graph with around 0.22 Osc index and 0.16RMS. Thats with a guide scope of almost 300mm FL. I think thats pretty good, infact I have seen worse with HEQ5's.......

Not sure what the arc second resolution should be with the EQ5/EQ3-2's......?

Hello Stan,

I take it that most logitech webcams will work? Does PHD have a list or do they have to have certain requirements?

I think I am going to get the £80 USB one as my laptop is quite new.

That diagram is really useful. Bit off topic but its really quite accurate at how everything looks, well done .

Thanks

Most webcams will probably work to some degree, BUT its the CCD sensor versions and even better the SONY ccd sensor versions like my 4000 pro that are best, but even the most sensitive CCD webcams will struggle on anything dimmer than a mag 6 star unles modded for long exposure.

PHD is not picky over what make/model it uses, you have no list to choose from as such, you just select the type of camera you're using i.e Atik 16, optistar, webcam...etc etc....

GPUSB is fine, most use it because they have USB available on there laptop. I have both, but choose to use serial because its more reliable and direct plug n play and cheaper!

Regards

Stan

Made a pretty picture on paint to try and help people understand my setup.

I use a standard unmodded logitech quickcam pro 4000. Its an early model with the SONY CCD sensor.

I use a GPINT'PT serial interface adaptor available from shoestring astronomy to connect to my laptop. Its plug n play, no additional drivers/software needed. I think people need to use ascom withthe USB versions. To me thats another program to get my head around so I stuck with good old serial port interface.

I also had a modded st4 port handcontroller as per quatermass, i.e shoestring astro EQ st4 port mod.

It really is as simple as the picutre suggests. Once connected PHD controls everything, no other programs needed, just the webcam driver running in the background when you fire up the webcam via PHD.

HTH

Stan

GUIDE SETUP.tif

Hmm, either way that LVI is probably asking to much of the EQ5 dual axis setup. I'm surprised they work as well as they do with HEQ5's....they will still have some backlash. Its just seems to particular for its own good.

BTW here is the webcam page link.

http://stargazerslounge.com/imaging-discussion/81143-alternative-philips-spc900nc.html

stan

Hmm, I think your problem may be the "duration" of the guide pulse, and maybe not the aggressivness. I may be wrong here and hope somebody can come along to comfirm/correct this with answers for you. I guess you can't adjust this.

dam

Don't give up QM!, I'm sure you can tweak things. Unfortunately I know diddly squat about the LVI, but surely you can adjust the command input settings? i.e guide pulse aggressiveness/duration etc...? I'm still getting to grips with PHD but I have the HC set to 4x speed, but I think any speed would work.... I'm not sure if all the various guiders/softwares account for set slew speed during the calibration process...?

If you do decide to go PHD/webcam its a mega cheap solution. The interface port will be your only real cost (and obviously you'll need a laptop or nearby PC)

Stan.

Hi Stan

I'm not giving up having come this far that for sure, having got this far I have come up against the first set of problems and they are all centred around the LVI auto guider.

Another chap on the forums from an older thread posted that he was using the LVI and the HEQ5 with no problems and getting good results. But, and here is the issue for me, the gears that come with the EQ5 dual axis motor kit dont have the guiding rates of the HEQ5 which are, 0.25x 0.5x 0.75x and 1x the LVI calibration process will give you a "Motors not moving" error message unless you lower the guiding rate down to 0.25/

SO as the guiding rate for the EQ5 dual axis motor kit gears is factory set to god knows what I cant change them.

Result of all that is the LVI auto guider will not calibrate correctly and any guiding going on is going to be to rough.

I have no experience of PHD or other computer related software for guiding but it would seem that it is doing a fine job for you with your dual axis kit so may be the best option. Given that auto guiders are supposed to be all singing all dancing solutions I have to say I am disappointed that the LVI can cope with a higher guiding rate.

Still looking on the positive side I have learned a great deal from doing the mod to my EQ5 mount and found out more about using the finder scope as a guide scope as well.

Question for me now is do I keep trying to get results from the LVI with my set up or forget it and turn my attention to the PHD laptop setup that you have working for you. With the EQ5 modded already I cant see any other option but to try it out.

Is the motors not moving message due to backlash though? baring in mind that LVI is looking for movement in the guide star, it doesn't actually know what the motors are doing in real time, it just sents the set command and waits to see the results through the guide scope. The motor I dare say is probably moving at 1x, but just not enough to take up slack in the drive to move the mount. Does the LVI say in which AXIS is not responding during the cal, or does it just say motors not moving?

Its such a shame that the LVI looks like it won't work for you, its half way there on its own being a self contained unit, how frustrating must that be

I would start looking now for a cheap webcam. Ideally spc880/900 but there are others out there. Il see if I can dig up the thread i found on here that lists the older CCD webcams.

Have you got a laptop? If not you can use your PC if its not miles from your scope. If you need a laptop get on the local gumtree add site, theres some real bargains on there. My advise (to keep things simple) get a laptop with a 25pin db25 serial port. Most older PC's/laptops had them. This way you don't have to worry about additional ASCOM software (required for USB interfaces), the GPINT-PT serial adaptor I use from shoe string is pure "plug and play" no software needed, just switch on laptop/plug in webcam/st4 lead and fire up PHD done job!

HTH

stan

If I am understanding all this correctly, the bottom line is the guiding speeds of the dual axis motor kits gears are too high for an autoguiding system. And if that is the case how come Stan is able to guide with phd and the laptop and webcam??

This is because the user can tweak all the settings in PHD to set the guide command pulses, i.e the aggessivness of the command and the duration of the command. The mounts motor speed doesn't really matter, PHD will deal with it.

Stan

Hi QM, Sorry to here about this problem, it may be a major one to! Maybe I was to quick to encourage you to go ahead with my rose tinted EQ3-2 setup glasses on

I assumed the LVI would guide as any other guide program would albeit in a slightly different format, but obviously not. Were these units really designed/marketed only for percific makes and/or models of mounts..? Surely all mounts have slightly different slew rates...?

Anyway, If the LVI has a set pulse rate then its probably game over for successful guiding. I know this isn't what you want to hear mate. I'm sure you could sell the LVI and have more than enough funds to get a suitable webcam. I got mine for around a fiver! Then you need an iterface. My serial interface was around £40 shipped from USA.

PHD is an awesome bit of kit, its free (but you can donate) and its very simple, and loads of people use it so theres loads of help available. IMO laptop/PC guiding is the way forward and besides ultimate portability offers the imager a lot more flexibility when fine tuning the whole setup, plus with additional extension cables (I got for a tenner from UK) you can sit in the warm indoors getting on with other things whilst keeping an eye on screen!

I hope somebody comes along soon with a simple cheap solution for your LVI but if not its not the end of the world, just another set back in the slippery slope to guided imaging. The PHD route is still going to be a lot cheaper than the HEQ5....

Stan:icon_confused:

I must admit I was genuinely nervous the first time I fired up PHD and hit the guide function. I hit the button and walked away saying to myself that it'll never work. A few moments later I went back into my garage where the laptop was and was gobsmacked to find bettlejuice perfectly centred in the cross hairs and that magical word "guiding" in the bottom left corner of the window

Now its just a matter of fine tuning everything and get that guide scope adapter made up. I found that when guiding the whole balance of everything makes life so much easier. Once you find the optimum balance point on the mount, keep it there! I have even put marks on the weight shaft etc.

Also QM, Precise polar alignment may not be an issue anymore. My PA was very very accurate tune over many nights on my pier so it always stayed put, but PHD couldn't handle it being this accurate. The star would move ever so slightly off in DEC over a long period of time but PHD wouldn't follow because the movement was so small! Doesn't make sense does it. So I have had to purposely move my PA off slightly in az. Many others have experienced this problem. I'm not sure if this will be the same with the LVI.......

Stan:)

BTW with regards to the HEQ5, I may be completely wrong here but the I think the *standard* HEQ5 has NO guide port interface. It just has a basic Dual axis controller similar to the EQ5. The Syntrek version have the ST4 port (i stand to be corrected).....

Stan

Congrats QM!! That moment you have been waiting for....

I know the feeling when that message appears on the screen for the first time. You can't help but smile......and take a picture!

Stan:D

Brilliant write up so far QM, good luck with you first guide attempt, hopefully that foam mod will hold the LVI secure enough not to give any diff flex...? that said on a 50mm finder it shouldn't be to noticeable if at all. I'll be keeping an eye on your progress, and I'm sure many others will to.

Stan