(November 2023)
This Quark combo was bought in Octo 2023.
General information:
- temperature of the oven increases when the tuning knob is rotated clockwise,
- body min temperature (7h position) = about 24°C, body max temperature (17h position) = 28 °C,
- measured CWL swing from min to max temperature = about 1 A,
- the CWL of this filter is on Ha when knob is at 7 h position (at 20°C ambient temperature).
Visual and imaging assessement:
To be done.
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),
- Sol'Ex spectrometer in a f/28 telecentric beam (Sun >> Takahashi TOA 150 >> Baader TZ-4 >> Quark combo >> Solex >> ASI462),
General information:
- temperature of the oven increases when the tuning knob is rotated clockwise,
- body min temperature (7h position) = about 24°C, body max temperature (17h position) = 28 °C,
- measured CWL swing from min to max temperature = about 1 A,
- the CWL of this filter is on Ha when knob is at 7 h position (at 20°C ambient temperature).
To be done.
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),
- Sol'Ex spectrometer in a f/28 telecentric beam (Sun >> Takahashi TOA 150 >> Baader TZ-4 >> Quark combo >> Solex >> ASI462),
| Filter | Test method | f-ratio | Surface measured | FSR | FWHM | Bandwith at 10% peak transmission |
| Quark combo | Ha lamp | NR | full aperture | 1.2 A | NR | |
| Sol'Ex in collimated light | collimated | 4 mm x 15 micron | 31.0 A | 0.9 A | 2.7 A | |
| Sol'Ex in f/28 telecentric beam | telecentric | 4 mm x 15 micron | 31.0 A | 1.0 to 1.1 A (consistent with 0.9 to 1.0 A in collimated beam |
3.0 A |
Test in diffused light and Ha lamp
Quark combo #2 (including BF) -
Nikon Z6 - Nikkor 50 mm f/1.8 S at f/2 - 800 ISO - 120 s exposure -
12-bit acquisition - red channel
Measured FWHM : 1.2 A
Value of n is set at 1.567 in order to find the same value of FSR (31.0 A) found with Sol'Ex.
NB :
The value of index n is set to 1.567 in order to get a FSR equal to 31.0 A, as found with Sol'Ex (see below).
The faint inner inteference ring is probabbly a reflection on the BF.
The second and subsequent interference rings are non symetrical (thinner on the left side).
Sol'Ex spectrometer: measurement in a f/115 telecentric beam
Optical setup: Sun => Quark with its BF => Sol'Ex spectrograph => ASI4290
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 but Sun at low altitude (about 20°)
Two succesive images :
- Solar spectrum (= no filter).
- Solar spectrum transmitted by the Quark combo (tuning knob at 17 h position). This spectrum is registered to the solar spectrum.
- Solar spectrum (= no filter).
- Solar spectrum transmitted by the Quark combo (tuning knob at 17 h position). This spectrum is registered to the solar spectrum.
The transmission profile of the etalon is given by the ratio "transmitted solar spectrum/solar spectrum".
NB : the bandwidth at 10% peak transmission is equal to 3 × FWHM, which is consistent with a Lorentzian profile.
Test in f/28 telecentric beam
Optical setup: Takahashi TOA 150 => Baader TZ-4 => Sol'Ex spectrometer => ASI462
Low altitude Sun (18-20°) - Blue sky
The results with the 125 mm and 200 mm f.l. variant of Sol'Ex are consistent. FWHM = 1.0 to 1.1 A
Test in collimated light and Ha lamp
Optical setup: Ha lamp => 2 or 3 mm aperture stop => Vixen Fluo 55 mm f/8 used as collimator => Quark with its BF => Nikon Z6 with 105 mm f/2.8 S Nikkor lens
Left : f/220 collimated beam (using 2 mm pinhole). Nikon Z6, 400 ISO, 4 s exposure, 105 mm S macro at f/4. RAW 14-bit. Red channel.
Right : f/146 collimated beam (using 3 mm pinhole). Nikon Z6, 400 ISO, 5 s exposure, 105 mm S macro at f/4. RAW 14-bit. Red channel.