Well, SHG works, but it seems my data are not of sufficient quality..
First, PIPP ROI selection has problems, there are errors when I specify tall and narrow crop area near the middle of the original frame.
I tried with default frame size which contains a lot of rubbish (noise, inverse band (produced by spectrometer - I will have to screen that somehow if I can't find something better for ROI extraction)), so SHG is totally confused.
It seems SHG expects only one line in video, or locks on the first one found?
If so, perhaps I can position the line of interest (H-alpha.. at the moment it is near the centre of the frame) at the left-most side of the frame, in which case PIPP will be able to discard unwanted right part.
ImageJ should allow you to crop any area/ zone of your AVI file.
Yes, as I mentioned before INTI needs to see a prominent absorption line within the ROI.
I think you’re beginning to appreciate the issues involved in obtaining a worthwhile SHG image.
Your focus is probably not good enough to give a clean contrasty solar image.
Practice, practice, practice…….
Since using my EQ3-2 mount for the Sun scan takes 3 minutes (when tracking is disabled), I searched for a quick solution for suitable tracker.. and found this one (The first one, tracker).
The only variables I needed to modify were TIM_FAST. and char sm_tab[8][4] (I am using full step with pause to save power).
The rest was OK for my mechanical setup.
New electronics (Arduino NANO) will fit inside EQ3-2, inserted into existing PCB (designed for 68HC705KICS (pic attached), which I still intend to use for that mount).
I found the old objective from Russian Smena-8 35mmm film camera in my stash..
FL is 40mm, outside diameter is a little bit too wide (ø24 mm) but it will fit inside barrel-adapter as projecting lens onto IMX291 sensor (I managed to remove the IR filter, it was glued with silicone rubber on the glass lid).
IMX291-based camera mounted on Hartridge spectrometer (tuned to 656.3 nm), ready for test... (clouds.. everywhere).
Adapters were machined from PVC 32mm fittings from Bunnings.
Shown on the second image is the spectrum of spiral fluorescent lamp, taken with the same setup.
I gave up on Hartridge spectrometer (for now). Mostly because of focusing (not easy at all) and relatively low aperture (effective slit length is ~2mm, maybe a bit more).
So I am back to fiber reflective slit...
In the meantime I figured out the Holman T32mm tee joint is mechanically perfect for improvised housing for fiber slit.. It can accommodate M42x1 (or T2) threads with minimal machining (ø42mm, so I have to add ~0.6 mm of material in a form of a thin ferrule, or use one of those from ebay), so Pentax (or Macro Rubinar 500mm F/8 in my case) lenses can be easily attached to the setup
Also, I added eyepiece to project Sun's image on white screen (together with fiber) to make focusing on slit easier.
So - there will be another version of the hardware, with some 3D printed parts (articulate joint to select wavelength)...
Attached Thumbnails
PET-G? I have just finished printing the Sol'Ex SHG and I found when I was printing the main body parts that I had to turn off "Part Cooling" in the slicer program because I was getting layer non-adhesion, cracking and warping. It might be worth a try to turn it off with a re-slice of the STL?
PET-G? I have just finished printing the Sol'Ex SHG and I found when I was printing the main body parts that I had to turn off "Part Cooling" in the slicer program because I was getting layer non-adhesion, cracking and warping. It might be worth a try to turn it off with a re-slice of the STL?
it is ABS..
Yes, I was thinking about cooling, but then again switching it OFF may affect supports..
Upon closer inspection I saw the problem probably started with poor adhesion of the base to the plate at edges.. ((maybe plate was not clean enough?)
So next time I will try with increased filament flow a bit (by 1%, to improve layer sticking) and to change the design by separating base and walls into smaller segments and glue them together later (and save some filament in case individual parts are usable or repairable).
As for this particular print session, I removed separated layers and figured out I can re-use the base, since the separation occurred abruptly at 11 mm height. So I will just print what's missing and glue it together and see how it goes.
Great work, ABS always have issues with adhesion try using a raft, I mainly print in PLA made a couple of camera adapters without any issues strength wise
Here is a result... now, gluing (with acetone). And perfect fit... as per design :-)
For adhesion I am using capton tape.. usually it is OK, but it needs to be cleaned with alcohol immediately before print job.. Sometimes it is hard to remove the finished part.
Inner shell (that will hold Holman tee and Smena-8 lens) is finished..
There was a bit of layer splitting, but I applied superglue to the crack when noticed it is happening..
The next step now is printing the base lid, then gluing to the shell, and then machining to have a fine fit when rotating shells inside each other.
