The Sun in Ca K-line light.

Two overlapping 3000-frame AVIs were captured with AstroDMx Capture for Windows through an f/5.5 Ekinox 80mm ED refractor fitted with a Baader OD 3.7 solar filter, with an SVBONY SC432M air-cooled CMOS camera, fitted with a Baader Ca K-line filter and a 5x Balow lens alone (giving 3x increase in focal length). 

The equipment used

AstroDMx Capture for Windows was used to capture the two, overlapping 3000 frame AVIs in 8 bit mono.

Flat frames were captured while the scope was pointing at the Sun. using a material that I have previously used for making H-alpha solar flatfields. It is 0.1mm thick, translucent thermoplastic polyurethane, frosted waterproof material. The material was stretched over the front of the Baader solar filter material and was held in place with a rubber band. The material was a low cost purchase from Amazon and proved to be a very effective diffuser.

The setup for flat field capture

The best 95% of the frames in each AVI were stacked in Autostakkert!4 with 1.5 Drizzle. The two resulting images were stitched in Microsoft ICE. The image mosaic was wavelet processed in waveSharp and post processed in GIMP and ACDSee.

Ca K-line image of the Sun

Full size image

Although the SC432M camera is intended for use with long focal length telescopes, this experiment shows that it can be used successfully with short focal length scopes and a Barlow lens. It must also be remembered that the diffuser material is NOT a solar filter and MUST be used in conjunction with the proper solar filter if the Scope is pointing at the Sun. However, it can be used without the solar filter only if the scope is pointing at a different part of the sky, well away from the Sun in order to capture flat fields.

William Optics 81 mm ED APO refractor with an Altair Hypercam 533C 14 bit OSC CMOS camera.

The equipment comprised a William Optics 81 mm ED APO refractor with a 0.8 flattener/reducer ED APO refractor with an Altair magnetic 2" filter holder with an Altair 6nm dualband filter Ha/OIII or an LPRO-MAX filter depending on the object being imaged; a  ZWO EAF and an Altair Hypercam 533C 14 bit OSC CMOS camera.  

The equipment used

The data were captured with AstroDMx Capture for Windows. The scope was mounted on an AVX GOTO mount which was controlled by AstroDMx Capture via an INDI server running on the imaging computer indoors.

The mount was placed on permanent marks on the ground which quickly gives quite a good polar alignment if care is taken with the placement of the tripod feet.

An SVBONY SV165 guide scope with a natively connected QHY-5II-M guide camera was used for PHD2 multistar pulse auto-guiding via the INDI server. The auto-guiding was controlled by a separate Linux laptop indoors.

Screenshot of autoguiding whilst imaging M13

AstroDMx Capture sent the scope/mount to a bright star which was used to focus the scope with a Bahtinov mask. The ZWO AEF was controlled by AstroDMx Capture via the INDI server.

Screenshots of the capturing process

Capturing RAW data on M13 showing the general green cast to the preview

The same preview with the non-destructive DMx White Balance turned on, producing a more realistic and pleasing preview

Screenshot of the preview whilst imaging M101

Screenshot of AstroDMx Capture whilst imaging the Chinese Dragon nebula showing a negative preview

Screenshot of the preview of the Chinese Dragon nebula with a normal preview with DMx White balance turned on

The exposures for the three objects were as follows:

M13: 60 minutes of 5 minute RAW exposures

M101: 35 minutes of 5 minute RAW exposures

The Chinese Dragon nebula, NGC 6559: 90 minutes of 5 minute RAW exposures

The data were debayered, calibrated, stacked and partly processed in PixInsight and post processed in Siril, GraXpert and Gimp 2.10 with Starnet++. 

M13

M101

NGC 6559, The Chinese Dragon nebula

RGB

HOO palette

These imaging sessions were for testing AstroDMx Capture following Nicola's major refactoring of the code for Touptek derived cameras, making the program more efficient and stable.

First light for an Altair Hypercam 533C and AstroDMx Capture

The equipment comprised a Stella Mira 66 ED APO refractor with a field flattener and Altair magnetic 2" filter holder with Altair 6nm dualband filters (Ha/OIII' SII/OIII); a  ZWO EAF and an Altair Hypercam 533C 14 bit OSC CMOS camera.  

The data were capture with AstroDMx Capture for Windows. The scope was mounted on an AVX GOTO mount which was controlled by AstroDMx Capture via an INDI server running on the imaging computer indoors.

The mount was placed on marks on the ground which quickly gives quite a good polar alignment if care is taken with the placement of the tripod feet.

An SVBONY SV165 guide scope with a natively connected QHY-5II-M guide camera was used for PHD2 multistar pulse auto-guiding via the INDI server. The auto-guiding was controlled by a separate Linux laptop indoors.

AstroDMx Capture sent the scope/mount to the star Arcturus which was used to focus the scope with a Bahtinov mask. The ZWO AEF was controlled by AstroDMx Capture via the INDI server.

The Altair Hypercam 533C OSC camera was chosen because like all Touptek derived cameras, it can produce true RAW images. That is, there are no destructive controls such as gamma and white balance applied before the data are saved. A result of this is that the RAW data have a green hue when viewed. This is perfectly normal because in the Bayer matrix of colour filters over the pixels, half of the filters are green whilst a quarter are red and a quarter are blue.

Although this can be distracting and even disappointing when previewing the data, AstroDMx Capture's non destructive DMx white balance control (which does not affect the save data) removes the green hue and correctly white balances the preview. The true RAW nature of the data means that no information has been lost during the capture process and everything has to be done during processing and post processing. An advantage of capturing RAW data is that the file size is only a third of the size of  fully debayered RGB data files. Some capture software can only capture RAW data but AstroDMx Capture gives the option of saving fully debayered, 16 bit data, and the user can choose the quality of the debayering algorithm used.

Screenshot of AstroDMx Capture capturing RAW fits files of M16, the Eagle nebula  but the non-destructive DMx white balance is turned on to correctly white balance the preview.

Capturing with the Ha/OIII dualband filter

Capturing with the SII/OIII dualband filter

Calibration frames were also captured

The two sets of data were debayered, cosmetically corrected, stacked  and partly processed in PixInsight and further processed in GraXpert, Gimp 2.10 and Starnet++.  The colour channels were decomposed to produce Ha and OIII data from one filter with SII and OIII from the other filter.

The starless OIII data were combined from both filters and composed back into various palette renderings in the Gimp. The SHO data were further selective colour processed in Photoshop CS2 and all of the palettes were post processed in the Gimp.

Two bicolour palette renderings of the Eagle nebula were made:

HOO palette

SOO palette

SHO Hubble palette

HOS, Canada, France, Hawaii telescope palette

 

Solar imaging

Using the same camera/scope setup with a Baader OD 3.8 solar filter and a UV/IR cut filter in the magnetic filter holder. AstroDMx Capture for Windows was used to send the scope to the Sun and to capture a 1200-frame RAW AVI of the whole solar disk.

Screenshot of AstroDMx Capture capturing RAW, 8-bit solar data

Notice the green hue of the RAW data.

Screenshot of AstroDMx Capture capturing RAW, 8-bit data but with the DMx white balance turned on

The data were debayered and the best 85% of frames stacked in Autostakkert!4, wavelet processed in waveSharp and post processed in the Gimp 2.10.\

The Sun in White Light