Guide Cameras

[Freddie]

Gina, the other thing you could do is increase min motion. I have mine at 0.15. If too low, you can get guide commands sent when it is just seeing that has moved the guide star.

[x6gas]

Thank you Tim I've been gradually reducing it.

It looks like my PA is still a bit off - the Dec graph is consistently to one side of the x-axis.

I sometimes get this too. The guiding is still good, obviously, so long as PHD doesn't suddenly decide to properly centre the star halfway through the sub. I don't know if it is an artefact of PHD trying to keep the DEC guiding on one direction. If I stop guiding, re-select the guidestar, and re-start guiding it goes back to normal...

[Gina]

Gina, the other thing you could do is increase min motion. I have mine at 0.15. If too low, you can get guide commands sent when it is just seeing that has moved the guide star.

Thank you Freddie - I'll try that

[Gina]

I sometimes get this too. The guiding is still good, obviously, so long as PHD doesn't suddenly decide to properly centre the star halfway through the sub. I don't know if it is an artefact of PHD trying to keep the DEC guiding on one direction. If I stop guiding, re-select the guidestar, and re-start guiding it goes back to normal...

Interesting I didn't get this before when I was using the ST80 and QHY5. I've tried stopping, reselecting and restarting and it still settles a bit away from the axis. The guiding is working well though - I was running 30m subs last night and still getting nice round stars

[Gina]

Be interested to see how you get on, Gina.

I have my Lodestar working very well with PHD

[ollypenrice]

I have one laptop that absolutely refuses to recognize the Lodestar, whether I try in AstroArt or PHD. I've run the setup disk as usual but nothing. I get a message saying it isn't recognized but I don't get an offer of pointing to the file where it's installed. In our two other laptops it is recognized fine. The grumpy PC is XP and the ones that work are Vista (miracle!) and 7.

Re fine focus of guide scopes, Craig Stark says don't. He says a softer focus is actually an advantage for centroid calculating.

Olly

[Gina]

Strange! Although I've had a career dealing with computers - both hardware interfacing and software, I still reckon they're black magic at times. I had a problem with the Lodestar last night not being seen though the red light was on. I unplugged the USB from the Lodestar and plugged it back in and the usual "music" declared that it had been recognised by Windoze (XP). After that I was in business That's in spite of having the cable looped back and tied to the camera body with a velcro strap.

I should add... that apart I've found the Lodestar to be superb and now have no problem getting two or three stars in the frame for guiding. Calibration took around 10 counts in each direction last time and using PHD set for 2s integration time, guiding with OAG on the MN190 is better than it was with the ST80 and QHY5. I'm quite looking forward to trying it with the ED80 and OAG but I'm doing galaxies with the MN190 first.

[Gina]

I've got a problem - it started last night, intermittently and lost me a couple of hours imaging. Last night I started losing the guide star. One guiding exposure it was there the next gone. Sometimes it would stay visible for quite a while with just occasional NO STAR errors in PHD and then show nothing. This was with a bright star and a clear night. Tonight it appeared for a while but now has gone completely. The Lodestar software also shows a totally black image so I don't think it's software. I checked the camera this afternoon on distant trees to see if I had the prism too far out but I got a perfectly good image which was steady - no signs of being intermittent. This was with the SX software as it needed an exposure of 1ms and PHD won't go down that far.

One other difference lately... When I was first using the Lodestar I was getting a noisy image with brighter stars showing much like the QHY5 except that the QHY5 had horizontal noise stripes and the Lodestar was random. Lately I've seen no noise even without a dark frame just points of light on a black background. One or two hot pixels and stars. I don't know if this indicates anything but it's a difference.

Anyone any ideas? Has my lovely new Lodestar developed a fault, do you think? I've tried waggling cables and unplugging the USB and plugging back in. Just the usual sounds that Windows makes on disconnecting and reconnecting a USB device.

[ollypenrice]

Yes, it may be those darned cables in my view. That's the message I got when the cables were faffing around on Yves' setup. Eventuyally the ST4 just left its plug behind in the camera when I pulled it out to check it. But maybe you are pulse guiding? In which case the USB?

Olly

[Gina]

Yes, it may be those darned cables in my view. That's the message I got when the cables were faffing around on Yves' setup. Eventuyally the ST4 just left its plug behind in the camera when I pulled it out to check it. But maybe you are pulse guiding? In which case the USB?

Olly

Thanks Olly Yes, I'm pulse guiding so USB only. The OS thinks the device is plugged in and working and waggling the connector has no effect. I'm using the supplied USB cable bundled up and attached to the camera body with a velcro strap. I'll try another cable and do more tests in daylight. But I did wonder if the camera was for some reason, working with short exposures but not long ones. I guess I can work out some experiments I can carry out in daylight/indoors.

It's annoying when equipment playing up stops imaging when we have a rare clear night! I did take some short subs of M51 though - unguided. 30 x 30s L and 15 each 30s RGB binned 2x2. Don't expect it to add much to what I've already go though I just had to grab something.

[x6gas]

Oh dear Gina - I feel your pain. It's such a shame to lose any imaging time when clear nights have been such a rarity...

I had trouble with my filter wheel over the weekend; it just wouldn't select the 4th and 5th filter. Luckily I realised so switched to gather more luminance on the first night. I thought I'd fixed it, but then had the same trouble last night so lost 90 minutes reinstalling software and finally taking the wheel apart! Rather frustrating, but that's imaging!

[Davey-T]

Sorry to hear about your prob's Gina. Is there anyone local you can borrow another Loadstar from to try ?, at least it would eliminate the camera .

You'd be welcome to borrow mine but I'm not exactly "local".

As you say really annoying, Iv'e had a few frustrating nights when equipment refused to work and then worked fine in the light of day.

Dave

[Gina]

Thank you

[Gina]

Sorry to hear about your prob's Gina. Is there anyone local you can borrow another Loadstar from to try ?, at least it would eliminate the camera .

You'd be welcome to borrow mine but I'm not exactly "local".

As you say really annoying, Iv'e had a few frustrating nights when equipment refused to work and then worked fine in the light of day.

Dave

Thank you I've been testing the Lodestar indoors with a different USB lead direct to my netbook using a camera lens that will go down to f22. Using PHD at 0.05s exposure. Getting a good picture in the relatively dull conditions. I thing the lead is very critical with these mini Usb connectors it seems - I've had problems with other devices with mini USB too. This is one reason I'm not now using Arduino Nanos with their mini USB conector.

[Gina]

Oh dear Gina - I feel your pain. It's such a shame to lose any imaging time when clear nights have been such a rarity...

I had trouble with my filter wheel over the weekend; it just wouldn't select the 4th and 5th filter. Luckily I realised so switched to gather more luminance on the first night. I thought I'd fixed it, but then had the same trouble last night so lost 90 minutes reinstalling software and finally taking the wheel apart! Rather frustrating, but that's imaging!

[Gina]

Sorry to hear about your prob's Gina. Is there anyone local you can borrow another Loadstar from to try ?, at least it would eliminate the camera .

You'd be welcome to borrow mine but I'm not exactly "local".

As you say really annoying, Iv'e had a few frustrating nights when equipment refused to work and then worked fine in the light of day.

Dave

Thank you I've been testing the Lodestar indoors with a different USB lead direct to my netbook using a camera lens that will go down to f22. Using PHD at 0.05s exposure. Getting a good picture in the relatively dull conditions. I thing the lead is very critical with these mini Usb connectors it seems - I've had problems with other devices with mini USB too. This is one reason I'm not now using Arduino Nanos with their mini USB conector.

[Gina]

I'm sure I don't know what's up with this board - duplicate posts, posts that won't er... post, posts that won't edit etc.

[Gina]

I now have the Lodestar back on the OAG and running from the netbook via USB powered extension, powered hub and the different USB cable. All seems well with both the SX software and PHD. Currently watching an image of distant trees on the horizon with PHD running 0.05s exposures as it gradually gets darker So far so good. There are clouds about but considerable patches of clear sky so keeping fingers crossed for after dark

[Gina]

11:20pm and Lodestar is working fine Using PHD, guiding is working well and I'm currently adding some extra data to my M51 LRGB with 2m L and 1m RGB binned 2x2. With these exposures none of the stars are being over exposed though a couple are quite near the limit. Forecast is showing clear sky until around 3am when cloud and light rain is due so I daren't leave it running with the roof open while I go to bed. OK - so I need cloud detection and automation to park the scope and close the roof Maybe one day...

[sloz1664]

Hi Gina,

Great to see you are up and running, and OAG as well. Arn't nice clean images from the lodestar,

nothing like the foggy/lined images I used to get from my QHY5. BTW have are you checking your star exposure?

Don't forget to post your finalised image of M51

cheers

Steve

[Gina]

Hi Gina,

Great to see you are up and running, and OAG as well. Arn't nice clean images from the lodestar,

nothing like the foggy/lined images I used to get from my QHY5. BTW have are you checking your star exposure?

Don't forget to post your finalised image of M51

cheers

Steve

Thank you Steve Yes, now I'm using a different USB cable the Lodestar is working a treat and I'm getting 3 or 4 stars to choose from, sometimes more In some cases I've gone back to 1s integration/exposure. PHD calibration is generally in 10 steps in each direction. S/N is good enough without darks Yes, a proper random noise background as you say and I agree about the QHY5.

I will be posting an updated M51 sometime today plus a quick first go at M63, Sunflower Galaxy.

[sloz1664]

Sorry Gina,

What I meant to say was:- How are you checking your star exposures. (silly predictive texts + old age + trembling fingers.....)

cheers

steve

[Gina]

Ah right... I use the preview in Artemis Capture by moving to pointer over the area to check - it gives you the ADU value of the image at that point. Full white is 65535 - any stronger incoming data is clipped to that value.

Ummm... That's for the main image - if you mean for guiding, I'm not. I just alter the exposure for the best result.

[sloz1664]

Yes thanks Gina, it was for the main images.

cheers

Steve

[Kenza]

From what I've read about Lodestar cameras, they sound superb so hopefully you'll now be spoilt for choice for guide stars.

I was going to suggest keeping an eye out for a secondhand Meade DSI - I've been using the V1 OSC variant for a few years now and it has worked a treat. But anyway, you're already sorted.

Can you guide with a Meade DSI? I am imaging with a DSLR.