(August 2023)
This Quark combo was bought in 2023.
General information:
- temperature of the oven increases when the tuning knob is rotated clockwise,
- min temperature (7h position) = 29°C, max temperature (17h position) = 40.1 °C,
- CWL swing from min to max temperature = 1.2 A (=(40-29)/9 ),
- the CWL of this filter is on Ha when knob is at 9 h position (at 25°C ambient temperature).
Visual and imaging assessement:
The contrast of images is very low. Double-limb effect is prominent.
Testing approach and main results:
The filter was measured using the following approach:
- Ha lamp (diffuse light),
- Sol'Ex spectrometer in a collimated beam (Sun >> Quark combo >> Solex >> ASI290)
General information:
- temperature of the oven increases when the tuning knob is rotated clockwise,
- min temperature (7h position) = 29°C, max temperature (17h position) = 40.1 °C,
- CWL swing from min to max temperature = 1.2 A (=(40-29)/9 ),
- the CWL of this filter is on Ha when knob is at 9 h position (at 25°C ambient temperature).
The contrast of images is very low. Double-limb effect is prominent.
Testing approach and main results:
The filter was measured using the following approach:
- Ha lamp (diffuse light),
- Sol'Ex spectrometer in a collimated beam (Sun >> Quark combo >> Solex >> ASI290)
| Filter | Test method | f-ratio | Surface measured | FSR | FWHM | Bandwith at 10% peak transmission |
| Quark combo | Ha lamp | NR | full aperture | NR | 2.0 to 2.1 A | NR |
| Sol'Ex spectro (fc =fi = 125 mm, ASI290, 0.0757 A/px dispersion) |
f/115 | 10 micron x 4.5 mm | 20.1 A |
2.0 to 2.1 A |
NR |
Test with the Ha lamp
Quark combo - Nikon Z6 - Nikkor 50 mm f/1.8 S at f/2 - 800 ISO - 20 s exposure - 12 bit acquisition - red channel
Measured FWHM is between 2.0 to 2.1 A
Sol'Ex spectrometer: measurement in a f/115 telecentric beam
Optical setup: Sun => Quark with its BF => Sol'Ex spectrograph => ASI462
10 microns slit, 125 mm collimating lens, 125 mm imaging lens, ASI462 camera, 12-bit acquisition.
Measured dispersion = 0.0757 A/pixel
Conditions : blue sky
Four succesive images :
- Solar spectrum (= no filter).
- Solar spectrum transmitted by the Quark combo at ambiant temperature (about 23°C). This spectrum is registered to the solar spectrum.
- Same as above, but different vizualisation thresholds.
- Solar spectrum (= no filter).
- Solar spectrum transmitted by the Quark combo at ambiant temperature (about 23°C). This spectrum is registered to the solar spectrum.
- Same as above, but different vizualisation thresholds.
The FSR is between 20.1 and 20.2 A
The transmission profile of the etalon is given by the ratio "transmitted solar spectrum/solar spectrum".
The direct measurement on the graph at 50 % peak transmission give an FWHM of 2.2 A, which is consitent with the measurement with the Ha lamp.
NB : the intensity of the two transmission peaks at -20A and +20 A is not equivalent, which is a possible indication of the BF transmission curve not centered on Ha.