Search found 552 matches

by thesmiths
Thu Oct 06, 2022 6:09 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha SHG, Oct 6 -- good seeing
Replies: 1
Views: 37

H-alpha SHG, Oct 6 -- good seeing

It is quite a challenge to get any imaging done this time of year as I have to catch the Sun as it passes between rooftops. This is the problem doing astronomy in central London. On the positive side, the cool autumn air appeared to have much less turbulence. During the summer, I could only image fo...
by thesmiths
Thu Oct 06, 2022 8:59 am
Forum: This is SolarChat !!
Topic: Today's SUN (20221005) | Good seeing again
Replies: 14
Views: 144

Re: Today's SUN (20221005 | Good seeing again

Hi Pedro, are you now always doing effectively a double stack with your LUNT152 in H-alpha (using the internal etalon and the DAYSTAR QUARK) ?
by thesmiths
Tue Oct 04, 2022 11:30 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Lhires III SHG set up + images from 2nd Oct 22
Replies: 6
Views: 124

Re: Lhires III SHG set up + images from 2nd Oct 22

Hoya ND16 filter sits on the front of the scope and behind this is a cardboard disk with a 40mm hole so as to bring the scope to f/10 matching the Lhires. One benefit of this spectrograph is the guide camera (ZWO ASI130MM with ND 3.0 neutral density) allowing me to keep a check on focus and where o...
by thesmiths
Sun Oct 02, 2022 9:22 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: CaK spectroheliogram 220929
Replies: 10
Views: 132

Re: CaK spectroheliogram 220929

The other reason for my selecting the 1200 is I want to give the Ca II at 8542.1 a go and the 2400 will not rotate that far on the Lhires. Actually no 2400 l/mm grating can access that far into the IR. I have tried that wavelength a few times without much success. It's quite challenging. Eventually...
by thesmiths
Sun Oct 02, 2022 10:12 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: CaK spectroheliogram 220929
Replies: 10
Views: 132

Re: CaK spectroheliogram 220929

Using my Lhires III with 15um slit and 1200l/mm grating and QHY5III 178M to carry out a solar scan yesterday afternoon in the calcium K line with the Evostar 72ED (stopped own to 40mm) and neutral density filter. 2022-09-29-1542_0-U-L-Sun_QHY5III178M_shift=0_clahe_proc.jpg Most people might have mi...
by thesmiths
Thu Sep 29, 2022 9:44 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Photo summary of our 106mm / 720mm long-slit SHG
Replies: 5
Views: 158

Re: Photo summary of our 106mm / 720mm long-slit SHG

how do you assure frames are the same size for stacking? If you are using our software (see https://solarchatforum.com/viewtopic.php?t=38137 ), then for full-disk scans, you can just choose the option " Crop square ". It then makes the width the same number of pixels as the height. Normal...
by thesmiths
Wed Sep 28, 2022 2:54 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Photo summary of our 106mm / 720mm long-slit SHG
Replies: 5
Views: 158

Photo summary of our 106mm / 720mm long-slit SHG

I realised that the photos of our SHG equipment setup were scattered across several different threads and even I had trouble finding them. I decided therefore to collect them all in one place and add some commentary. https://solarchatforum.com/download/file.php?id=71090 Recent photo of our SHG setup...
by thesmiths
Tue Sep 27, 2022 9:36 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: SHG software release version 3.6.2
Replies: 3
Views: 335

Re: SHG software release version 3.6.2

I had a message from one user that to run the .exe version on his computer he needed to " Run as Administrator " the first time. This is not an uncommon issue with Windows and probably depends on the security settings on your computer (high, low, medium). I never saw this happen with any o...
by thesmiths
Mon Sep 26, 2022 5:48 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha, H-beta and Ca-K SHG images from Sept 25
Replies: 8
Views: 175

Re: H-alpha, H-beta and Ca-K SHG images from Sept 25

As a little experiment, I took the Calcium K data and applied a pixel shift of +4 and stacked the best 6 frames. This is therefore a slightly off-band image , although still very narrow band. The results are the following: 250922-CaK-720mm-72mm-stack-6-shift-4.jpg The contrast becomes much less : th...
by thesmiths
Sun Sep 25, 2022 6:43 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha, H-beta and Ca-K SHG images from Sept 25
Replies: 8
Views: 175

Re: H-alpha, H-beta and Ca-K SHG images from Sept 25

Montana wrote: Sun Sep 25, 2022 6:33 pm I find the hydrogen beta very absorbing to ponder over.
I know what you mean. It's kind of a familiar face and yet a bit inscrutable.
by thesmiths
Sun Sep 25, 2022 4:53 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha, H-beta and Ca-K SHG images from Sept 25
Replies: 8
Views: 175

H-alpha, H-beta and Ca-K SHG images from Sept 25

The imaging window is getting really short for me now. With the Sun so low here in London, there is only a short time when there is no obstruction from trees and buildings . Unfortunately, SHG imaging is slow and when time is of the essence, choices need to be made. So today I decided to get three w...
by thesmiths
Sat Sep 24, 2022 12:16 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha SHG imaging from Sept 17
Replies: 16
Views: 335

Re: H-alpha SHG imaging from Sept 17

I am confused: 1. We are using a grating to select specific wavelengths. The ones not wanted go aside the sensor. An IR cut filter does not make any sense to me due to this physical behavior. 2. I want to take pictures at 850 nm. I am not sure, if an IR cut filter prohibits this (I do not know the ...
by thesmiths
Fri Sep 23, 2022 6:45 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: simple SHG caK
Replies: 7
Views: 175

Re: simple SHG caK

highfnum wrote: Fri Sep 23, 2022 4:36 pm I changed camera to asi290mm
In my opinion, the best camera for this kind of imaging is the 178MM. Smaller pixels and larger sensor. It's available at a good price these days.
by thesmiths
Fri Sep 23, 2022 12:09 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: simple SHG caK
Replies: 7
Views: 175

Re: simple SHG caK

If you try stacking a few frames, you will get rid of some of the noise (for example, the jaggedness around the edge of the solar disk and the very bright regions). But make sure that you get the full disk in all the frames you stack. And the stacking program typically requires all the frames to hav...
by thesmiths
Thu Sep 22, 2022 3:15 pm
Forum: Solar Software
Topic: SHG (spectroheliography) software release version 3.6.2 -- now with Windows executable!
Replies: 1
Views: 226

Re: SHG (spectroheliography) software release version 3.6.2 -- now with Windows executable!

EDIT : We made a technical change to how the user parameters are stored (based on a suggestion from a user) and decided to release a new version ( v.3.6.1 vs v3.6 ) with this change. A small fix was also done to how the " live view " graphics displays the reconstruction. The original post...
by thesmiths
Wed Sep 21, 2022 9:10 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: SHG software release version 3.6.2
Replies: 3
Views: 335

SHG software release version 3.6.2

See full description here: https://solarchatforum.com/viewtopic.php?t=38136 This update does not have any new user features; it mainly fixes a few known bugs. But some work was done to also create a Windows executable file -- so installing Python is no longer necessary unless you want to make change...
by thesmiths
Wed Sep 21, 2022 9:05 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: First attempt at solar scan 21st Sept 22
Replies: 9
Views: 146

Re: First attempt at solar scan 21st Sept 22

I set the ROI to make allowance for the curvature of the Ha line, image below, which is typical of the Littrow design. You could definitely make the ROI narrower -- that's really not that much curvature. Your camera is a little tilted with respect to the diffraction grating; if you correct that, yo...
by thesmiths
Wed Sep 21, 2022 8:32 pm
Forum: Solar Software
Topic: SHG (spectroheliography) software release version 3.6.2 -- now with Windows executable!
Replies: 1
Views: 226

SHG (spectroheliography) software release version 3.6.2 -- now with Windows executable!

We have done another minor upgrade to the previous version of our software. Mainly there are some bug fixes that I discovered over the last few months of using it. One small error crept in as a result of a Python library update that itself had a bug in it. I only noticed it when I recently got a new...
by thesmiths
Wed Sep 21, 2022 7:25 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: First attempt at solar scan 21st Sept 22
Replies: 9
Views: 146

Re: First attempt at solar scan 21st Sept 22

In general, I would try to scan as fast as possible. Your exposure time is extremely short; is perhaps your gain too high? In general, I try to use gain close to zero. You might also try to use a narrower ROI (below 200). That will increase the FPS. The exposure time obviously needs to be faster tha...
by thesmiths
Wed Sep 21, 2022 6:33 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: disassemble the quark.
Replies: 16
Views: 509

Re: disassemble the quark.

mami813 wrote: Wed Sep 21, 2022 11:53 am The two black lines in the center did not match, so I applied a little force to match the black lines. After assembly, it works without any problems.
Does that mean that it did not work properly before? But after reassembly it works better?
by thesmiths
Wed Sep 21, 2022 6:24 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: First attempt at solar scan 21st Sept 22
Replies: 9
Views: 146

Re: First attempt at solar scan 21st Sept 22

That looks very good, especially for a first attempt. Are the dark areas due to clouds? Was it not possible to scan faster because of the exposure time? I don't think you need both the ERF and an ND filter. Which reconstruction software did you use?
by thesmiths
Wed Sep 21, 2022 7:30 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha SHG imaging from Sept 17
Replies: 16
Views: 335

Re: H-alpha SHG imaging from Sept 17

fulvio.mete wrote: Tue Sep 20, 2022 3:43 pm I own a ZWO 290 MC, and the use of IR cut make a BIG difference in the output images.
Do you mean when using in one of your spectroscopy instruments? Or for another application?
by thesmiths
Mon Sep 19, 2022 2:43 pm
Forum: This is SolarChat !!
Topic: Saturday Sunshine 17th September
Replies: 16
Views: 261

Re: Saturday Sunshine 17th September

Your DS90 closeups look in quite nice agreement with the SHG closeup I did on the same day: https://solarchatforum.com/download/file.php?id=72579 . I can see the etalon was better able to cope with the slightly non-deal seeing conditions. Any kind of rapid fluctuations will smear out the SHG images ...
by thesmiths
Sun Sep 18, 2022 6:47 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Review of 3 Coronado 90's
Replies: 8
Views: 288

Re: Review of 3 Coronado 90's

I'm also guessing Ca-K filters have quite some variability also; there seems to be quite a range of results, even with those that have not been modded.

I never liked my H-alpha PST that much but I do love my Ca-K PST (I would part with it for a million though :D ).
by thesmiths
Sun Sep 18, 2022 5:51 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha SHG imaging from Sept 17
Replies: 16
Views: 335

Re: H-alpha SHG imaging from Sept 17

With regards to the 2-inch Astronomik L1 UV/IR filter that I recently installed: I have the impression that the data at the camera was a little cleaner than previously and was therefore easier to focus. This might be because before there was a lot of IR light bouncing around inside and the CMOS came...