Merlin66

As I’ve recommended in the past, before using spacers etc give the threads a smear of boot polish, this will significantly reduce the chances of seizures. To separate them another trick is to use the anti slip map you can buy for kitchen drawers, or a rubber flip flop and press the spacers into the material and twist.... Rubber gloves have also had success.

I'm having difficulty understanding your problem.... You say the two cameras are focused together - good. This is the bit I don't understand. Can you word it differently????

You may have to add a spacer between the OAG and the imaging camera to allow you to get the guide camera in focus at the same time.

Nigella, Just to show the selection screen used.......

Nigella, The hump around 5900A is due to the RGB filters on the Bayer Matrix in the camera.....

Nigella, That looks much better..... It calibrates at 8.6A/pixel which is good! and matches a spacing of around 43mm with the 100 l/mm grating.

Nigella, ok, open the Spectral image in BASS Project. Make sure it has the zero order image towards the left and horizontal to the chip. use the selection icon to select the Spectral image. look at the profile, the idea is to identify a prominent absorption line - say H beta Go to calibration select the zero order as “0” and the H beta as 4861 This should give you a calibrated profile. Crop the ends just to leave the main Spectral detail (roughly 3900 to 7000A). That’s a good starting point. I’ll have a look at your image........stay tuned.

Nigella, softly, softly..... what’s the grating spacing? This will help confirm the dispersion. If you use the zero order as the “0” wavelength and the third absorption dip as H beta (see the profile above) should get you started.

Nigella, Good start! Looking closely at your spectrum.... the dark lines at the left hand side are obviously the Balmer Series lines of Hydrogen. Playing around with possible solutions I can get a reasonable answer when the dispersion is around 40 A/ pixel (based on your ASI 224mc, 3.75 micron) but with a 100 l/mm grating this infers a distance from the filter to the chip of around 10mm - ie the filter is mounted inside the camera! I can only therefore assume that the image posted has changed scale from the original? What spacing do you have? I also think the 2nd order spectrum is overlapping the 1st order, giving the impression of a much longer spectrum. If you can post the original spectral image we can better analyse your results. Onwards and Upwards.

Another thought Re Noise.... Are you sure you're working with the brighter 1st order spectrum? Ken

Rusted, Well done! Some of the proms yesterday need a long exposure. Have a look at Sylvain's Corono for finishing your image.... http://sweiller.free.fr/Softwares/Corono/corono.html

Nigella, If you’re happy with the AS! results, then do what you do and import the image into. BASS Project. Ken

AR 2749 and friend, some filaments and proms. Enjoy!

John, Just imaging in CaK and Ha as I type this....... Stay tuned.

There's another AR following AR2749 onto the disk.....not numbered yet. Also a few interesting proms. Well worth getting out the Ha gear to get some practice.

Nigella, Just drop the image into BASS Project and you'll immediately see a spectral profile. Use the selections to just select the height of the spectrum (this will automatically remove the background). Calibrate by using the zero order as "0" wavelength, and pick a second prominent absorption line - usually H beta but look at what you've got - Gam Cass should show a peak, this is H alpha. Once you're happy with a calibration select a reference spectrum to match the type and look for similarities........ One step at a time........ We're here to help you on your journey. Ken

I saw this spot on the morning of the 1st just clearing the edge. Some flaring visible on the 2nd Oct. Managed to get some CaK and Ha images, as well as the proms.

Nigella, Well done! Looks like you're of to a good start. Onwards and Upwards.

Thanks for that. I downloaded Ansvr, but it seems to need an up front program to access it......

Failure of the Lunt BF front filter is not uncommon. Temporary improvement can be achieved with a soak in CLR, flush and wipe. Lunt can supply a free replacement if under warranty, or minimal cost otherwise.

The problem is that any “soft” filler catches the retaining screw or jambs in the locking ring. It really is a PITA......

Louise, You don't need RSpec... you'll see the difference in images using your normal capture software. I use AstroArt for acquisition and BASS Project for processing.

Louise, As has been said, you'll definitely get better results when you focus on the spectral image rather than the zero image. You should see the absorption features gain contrast and some clarity. Start with short exposures and don't worry about the zero order image being over exposed. Position the zero order towards the left hand side and the bright (1st order) spectrum close to the centre of your chip. Practise, practise......

Yeah, those "safety" undercuts are the Devil's work!!! I don't think the user - you and me - were ever consulted before the manufactures decided in our behalf that "all new product" would have them. Give me the smooth sided versions anytime.

@stash-old, Which platesolving package are you using? I've successfully used astrometry.net ASPS, and AstroArt in the past but they occasionally give me problems - I consistently use the same efinder and camera, so no changes between sessions.