![]() These narrowband filters are specifically tuned to only let through a single emission line: Hydrogen (H-alpha = 656nm), Sulfur (S-II = 672nm) and Oxygen (O-III = 501nm) so that much of the light pollution can be subdued. The images from these different filters are recombined to produce the full colour image. Since I live in an area with relatively high levels of light pollution (Milky Way is rarely, if ever, visible to any extent), I need to work with “narrowband” filters. It now only has a glass screen that lets everything from UV to IR and have had a lot of fun using this as a terrestrial monochrome camera (some example shots HERE). That means the blue/green/red sensor mask has been removed so that all the pixels can see all the colours (producing a monotone image). The SIGMA fp I have, has thus been de-bayered (very many thanks to Daniel ). Since there are no “green” Deep-Sky-Objects, the green pixels (50% of all available pixels) in a full colour camera are very under utilised. ![]() At 02:00 in the morning, sub zero temperatures, and already 6-8 hours “on the job”, keeping the mental discipline to get the focus right is not easy. This is probably the most difficult task and something that would be almost impossible to achieve without the focus motor and computational interpretation of the diameters of the stars. Its been (still is) a steep learning curve □ … From the first outings under an 85% moon (Rosetta/Orion/Horsehead Nebulas) and hard, high humidity frosts (Think – “The Day after Tomorrow” □ …) to every set-up and focussing error I can think of (and several I didn’t) … Focus is achieved using SharpCap, which takes the camera live-view feed after feeding through a field monitor, which is how I do most of my macro work, via a video capture card and the Celestron USB Focus-motor. My best results to date have been around <4 pixel drift over 40 Minutes = ~ 0,5 pixel drift with a single 5 minute exposure. I have used the IOS 6 setting on the camera to block the light of all but the brightest stars making the model building significantly easier (plus 8x zoom in the camera live-view plus 9x zoom in the field monitor – HDMI feed). 20 bright stars in turn and aligning these exactly. This needs a model of the sky to be built by going to ca. With Pluto remote trigger and HDMI cable and telescope dew heaterĪs a tracker I have a 10 Micron GM1000. The SIGMA fp is the smallest full frame camera in the world – a perfect match. In the configuration of this telescope the camera sits in front of the glass (see image), which means that it is imperative that the camera is as small as possible. Primarily driven by the desire to have as small an F-Stop as possible for the best possible light gathering properties. My choice of telescope is the Celestron RASA 11” (620mm, F2.2). SIGMA fp in place with the TC2011 2 x Converter and Baader Filter Faint Deep-Sky-Objects need very long exposure times at relatively high ISO values (most often around 1600 being a good compromise) and thus the control of digital noise is a fundamental factor towards producing a good image. ![]() There is one other type of photography where this is absolutely critical and that is astro-photography. This means that the camera is able to control digital noise extremely well. This can be seen on the sides of the camera. ![]() In order to be able to take video for several hours without overheating the camera has a heatsink built into it. Why the SIGMA fp ? This camera was designed as a stills and professional video camera. Having been encoded for maximum quality, there may be a slight delay to the image loading.Ĭopyright: As with all images on this website, none of the images in this article may be copied or reproduced in any form whatsoever. H-alpha / O-III / S-II narrowband image, 20 x 4 min., ISO 1600, F2.2, 620mmĬlicking on an image of a nebula will open a larger version in the Prodibi Viewer. The launch of the SIGMA fp I took as the starting point for the journey to realise that dream. As such I have always had as a dream that one day, perhaps, I would be able to work with images of these objects myself. In particular, the huge variety of Nebula and other Deep-Sky-Objects and the structures they contain. ![]() I have always been fascinated by the night sky. “The start of the journey …” (February 2022) Astro-Photography with the SIGMA fp (2).Coppers (Lycaena) / Browns (Aricia) / Hairstreaks (Theclinae).Blues (Polyommatinae / Pseudophilotes / Phengaris / Cyaniris). ![]()
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