yltansg wrote: ↑Sun Dec 10, 2023 1:58 am You mentioned using a spectro. I am guessing it is a professional test instrument. What model is it?

I think for filter testing, Christian now uses a fairly standard Solex spectrometer. It has resolution around 0.2 angstrom.

With regards to the solar scintillation monitor: would you say that the images are representative of the minimum values (e.g. 0.54, 0.47, 0.37 arcsec) or more like the average values? The Rayleigh criterion for the 300mm optics is around 0.36 arcsec at 430nm -- do you think you are quite close to th...

Hi Pedro, I think the IMX178 sensor helps. Your files are extremely large considering the spatial resolution possible with the 2-inch aperture. At what speed are you scanning your mount? In FireCapture you can reduce the FPS independent of the exposure time to slow down the acquisition. The ROI is a...

Maurice sent me two new images he took today (in Melbourne, Australia) with his 100mm aperture SHG. He said there were some high clouds but at least he's got some sun (unlike many of us in the northern hemisphere). He's currently testing out the new mounting method for my chrome on quartz slits; so ...

Thank you for posting more photos of your interesting setup. My experience with the C8 SE mount (with the single arm) is that it does not move very smoothly. It is really only for visual use. It was not even possible to use it for taking video images of bright planets like Jupiter because it jumped ...

It looks like a very nice modified design. I agree that having internal helical threads for the lenses is a good idea. The weakness of the Solex is the sliding mechanism for focusing the collimator lens. You say you used the Celestron 8SE. I assume you mean that was the mount (not the telescope). So...

Rodler wrote: ↑Sun Nov 19, 2023 7:05 am I would like to buy such a slit from you. Would it be possible?

All the 9 micron wide slits are now gone. But I will shortly be making a second batch of quartz slits, which will likely be 8 micron wide. You can send me a private message regarding the new batch.

I was emailing with Player One recently and received this reply: Dear Douglas, Thank you so much for your email. We will have a promotion in this month. I think Black Friday will be a good time to get a discount. ________________________________________ Sean Wang CEO | Player One Astronomy Company w...

cybermayberry wrote: ↑Sat Nov 11, 2023 12:12 am No real surprises, just what one should expect given the aperture. Seeing was excellent this AM.

In the very nice top photo, when it says arcsec, do you mean arcsec/pixel? Or you do mean Rayleigh criterion for the aperture?

the 12v battery on the EQ6 on the pier has finally died, I knew it was on it's way out, but seems last time I forgot to turn the mount off and it drained the battery completely flat, and now, no matter how hard I try it won't recharge. I had to change out the lead battery in my rechargeable power s...

I have to say that I'm still struggling to get decent results with my Sol'Ex. Hi Pedro, I noticed in a different post you said you were struggling with the Solex. A minor improvement can be achieved with a camera with the slightly smaller pixels than the 174MM. It turns out the best camera sensor t...

Even though we as amateurs probably never reach this crazy 0.12A bandwidth, I would suggest to shift this thread to the reference library. Very useful stuff here, if someone builds a super-high-(spectral)-res SHG in the future. Actually, I've calculated it would be quite straightforward to achieve ...

marktownley wrote: ↑Wed Nov 08, 2023 8:50 pm my experience of them was they performed much better in the focal plane rather than ahead of the objective.

I imagine that for a large diameter, the optical flatness needs to be a lot better (in terms of nm per cm) in order for the wavefront not to be distorted.

I was told me someone (Thierry G.) that the diffraction gratings are very good, equal to Edmund Optics. But he said the lenses are not so great. The 60mm 400nm filter could be front mounted on a telescope.

I was looking for some low-cost diffraction gratings and found an optics supplier in China that has some interesting stuff. I'll probably order a diffraction grating from them since it's about half the cost of those from Thorlabs and Edmund Optics (they have 2400 l/mm, 1800 l/mm and 3600 l/mm in var...

That's a very nice comparison. It confirms my impression that 80mm SHG gives results similar to 60mm DS at H-alpha.

Hi Pedro, it's a good first attempt with the Baader Vario Finder. The Y/X ratio is way off from the target of 1.0 -- were you just using the motion of the sun rather than scanning the mount? In FireCapture, you can change the FPS independent of exposure to reduce the number of frames. I can also sug...

This interesting configuration could in principle also be used for the CaK PST. The 40mm optics is not as much of a limiting factor at the shorter wavelength, but it's probably a quick and easy way to get 70mm to 80mm aperture. The CaK PST has a quite nice bandwidth (I think a little better than the...

highfnum wrote: ↑Thu Oct 26, 2023 8:19 pm apo80mm

That's really nice. So you put a 25mm square 3200 l/mm grating into the Solex?

highfnum wrote: ↑Mon Oct 23, 2023 9:11 pm home made SHG

So your homemade SHG is different than your Solex? So you sometimes use one and sometimes the other?

I've been experimenting with slightly longer exposure times to drop the gains in an effort to reduce noise. I've also adopted a new processing strategy to avoid overcooking things. This stack of 16scans was sharpened ever so slightly (No LR decon). Firecapture: 3.250ms/gain=100 Since you're mainly ...

I used to have a Vario-Finder many years ago. I found it was a little too good for a normal finder and not quite good enough to use for anything else (too much CA). This might be a good application. It's easy to move the focusing by large amounts but as I recall, making fine focus adjustments wasn't...

That looks good. Are you doing all the controlling from inside the house? I've put ZWO EAF focusers on all my telescopes now and try to do as much as possible from inside. I can focus much better on a big screen and there is also less chance of causing vibrations, etc.

I had a full disk on the same day too I kind of like the undersharpness of you images. I tend to favour that. I think Arne's is a little oversharpened. I believe his telescope was masked down to 50mm and is single stacked, but his seeing always seems to be excellent. Single stacked always seem to g...