alan4908
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Everything posted by alan4908
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From the album: Deep Sky III
I found the object very difficult to process due to the extremely bright core. The problem is that with 600s sec exposures, it was not possible to see anything but white in the core region. On inspecting the corresponding FITS images I discovered that whilst the ADU values of my CCD where not at their maximum level they where in the non-linear region of the my camera, which starts at around 47000 ADU's. After trying various techniques, I eventually watched an Adam Block tutorial video on how to create a high dynamic range image using CCDstack. Here, the approach is to take much shorter exposures (I choose 60s) and then combine them with the 600s exposures. The combination is done on a per pixel level by instructing CCDstack to reject any pixel from the 600s image that is 40000 ADU's or above and to replace it with the corresponding pixel from the 60s image. The result is a high dynamic range image for the LRGB channels which I then processed via my conventionally PS and Pixinsight workflow. The image represents just over 8 hours integration. -
From the album: Deep Sky III
A (slight) reprocess of the Bubble nebula which is also in this album. Here, I decided to focus on the medium bright stars and added slightly less luminescence in order to reduce their size and also increase colour. To shrink the stars slightly and also to make the star cores less white, I used the Pixinsight Erossion filter (under Morphological Transformation). To prevent the cores become too dim, I followed an Adam Block tutorial video recommendation and selected the 5 x 5 pixel diamond kernal filter. -
From the album: Lunar
A crop of the 50% LRGB Lunar X and V moon image, showing crater detail. -
From the album: Lunar
A semi-manual image of the 50% moon on 1st June 2017 taken with my Esprit 150. Whilst my DSO imaging set up was waiting for the moon to increase its angular distance from my selected DSO target, I took the opportunity to acquire some semi-manual images. I decided on an LRGB strategy since I wanted detail and colour contrast, so took 20 images per filter that where subsequently calibrated and stacked in RegiStar. I then followed my normal DSO processing workflow, sharpening the Lum component and boosting colour on the RGB composite. After I had finished processing the image, I noticed that, by accident, I had also managed to capture the so called Lunar X and V's - optical illusions that result in "X" or "V" shapes on the moon's surface. These are visible in transition region between the light and dark regions. -
From the album: Deep Sky III
Quite a short integration time for me (4.3 hours) basically because the LRGB image is largely made up of test shots of my new unguided imaging set up. I still haven't quite perfected the art of magneta star elimination such that the results looks good - I think I shall have do a bit more research on the topic. The image was processed in PS with the exception of Pixinsight which was used for DBE, Colour Calibration, SCNR Green and Multiscale Linear Transform, I was particularly impressed with the latter function as a method of extracting a little more detail from the bubble region. LIGHTS: L:8; R:6:G:5:B:7 x 600s. DARKS:20, BIAS:100, FLATS:40 - all at -20C. -
From the album: Automated Observatory
I decided to implement some observatory drainage channels. -
From the album: Automated Observatory
My new imaging set up from May 2017: a SW Esprit 150 with 3" Feathertouch focuser/stepper on a 10micron GM1000HPS. -
From the album: Deep Sky III
My first image with the Esprit 150 on my new mount (10micron GM1000HPS). Since the core of M13 is quite bright, to better reveal core details I decided to create two LRGB processed images: one with the Luminescence image stars DDP stretched such that the 8 bit PS values where less than 200 (to allow them to be easily coloured) and one where the stars exceeded the 200 value (which makes them quite bright). I then blended the two images via PS using the less stretched image for the core. The image represents about 4 hours integration. -
Pieter - thanks ! In addition to the Photoshop's High Pass Filter and Unsharp Mask, this time I applied Pixinsight's HDRMT routine, which is excellent at sharpening images. Alan -
From the album: Deep Sky II
This is an LRGB image with Ha blended in the Lum and Red channels. The Lum was quite faint, even after over 3hours, so I decided to blend quite a large amount of Ha in order make the image reasonably bright and not too red. The Ha is also blended into the Red channel but at a much lower level. I made a slight change to the Hue, towards the green, in order to get a slightly more appealing red. In total, the image represents about 13 hours integration time. -
From the album: Deep Sky II
A reprocess of my previous attempt which is also in this gallery. The major difference is that I attempted to correct the starfield which was distorted due to optical issues. I also applied the Pixinsight function HDRMT to get a slightly sharper result for the main galaxy. The net effect is that these changes allow me to present the image in a much wider field of view. -
Beating the weather (Cloud\Rain Sensor)
alan4908 replied to AlistairW's topic in Discussions - Scopes / Whole setups
Since I'm ultra cautious about mixing rain with electronics I use a total of three rain sensors in my obsey. The main one is from Hitech astro which I've set to close the roof if it detects rain or if it detects clouds, this is configurable for local conditions, it can also be configured to send email alerts. This has never failed but it is reliant on the obsey PC functioning. To guard against failure, I installed two backup sensors inside the obsey which are not reliant on my PC (so in theory these should never trigger). I initially installed a rain alarm weather monitor station which connects via a low frequency RF link to my house. The main advantage is that it is battery powered and is very simple to install. The main problem is that it needs quite a bit of rain for the alarm to trigger. I therefore decided to install a second device (a Kemo rain sensor) which is more sensitive, it also incorporates a heater which is required to prevent false triggering from dew. Since it incorporates a heater, I decided to power this from my main 12v power supply. To guard against mains power supply failures, I also installed a detector inside the house. For your particular application, you might find that the Kemo sensor is suitable, it's also relatively low cost http://www.maplin.co.uk/p/kemo-rain-sensor-dc-12v-n21dd?cmpid=ppc&gclid=CMHhlI3rg9ICFeq87QodbvsCdA and on rain detection it closes a self contained relay which you can use to trigger an appropriate alarm. Alan -
From the album: Deep Sky II
My second attempt at M45 (the first attempt with my SX26C is within the album Deep Sky I). Although this is not an ideal field of view, the close up of M45 does reveal quite a lot reflection nebula structure. The galaxy at the bottom right is PGC13696. I decided to go for quite a long exposure on the L to bring out the faint dust. I would like to have captured more green and blue data. In total, about 7 hours. LIGHTS:L: 19; R:12: G:5: B:6 x 600s. BIAS: 100; DARKS:30; FLATS: 40 all at -20C. -
Thanks Dan ! As I type this, I'm surrounded by dense fog, so I cannot even see the clouds.....hopefully this will improve ! -
From the album: Deep Sky II
A crop of the Sliver Needle Galaxy - the uncropped image is also within this gallery. -
From the album: Deep Sky II
An Uncropped view of the Sliver Needle Galaxy. I was quite pleased that I managed to extract a little colour and detail from the galaxy. The image was sharpened via three software packages: CCDstack (deconvolution); Photoshop (High Pass Filter and Unsharp Mask) and Pixinsight (HDR Multiscale Transform). The Pixinsight routine was particularly effective at extracting detail. I also tried the PS HDR toning routine but this was ineffective. The image represents about 8.5 hours of integration time - I've also included a cropped version within this gallery to show the galaxy details. -
From the album: Deep Sky II
Another attempt at the Heart nebula, this time with my Trius 814 camera using a 3nm Ha filter. The Ha was blended into both the L and Red channels via PS screen. I also decided to correct the star colours stars by taking the RGB layer and PS screening this with the LRGB + Ha. I quite like the variety of stars colours, so I decided not to push these into the background too much. -
From the album: Lunar
Believe it or not this is only my second lunar image.......I had just performed a software upgrade with MaximDL and was checking to see everything was OK. At the time a nearly full moon was present so I decided to take a few subs. Since ACP does not support lunar capture (it cannot change the tracking rate to lunar) I had to do a semi manual acquisition using ACP to perform the autofocusing. I selected my 3nm Ha filter since I thought it would give more contrast compared to the Lum. I took 20 subs each of 0.1s and stacked then in Registar. I then post processed in Pixinsight and PS - not sure if I have sharpened this too much, time will tell. -
Five images from 2016 - all taken with my Trius 814 and SW Evostar 80ED DS Pro: M51 M33 M31 - (my first mosaic) M106 NGC6888 Alan
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From the album: Deep Sky II
An LRGB image representing about 7 hours integration time. LIGHTS: L:14, R:9, G:10; B:8 x 600s. DARKS: 30; BIAS 100; FLATS:40 all at -20C. -
From the album: Deep Sky II
A heavily cropped image - taken from the image Deer Lick Group and Stephan's Quintet which is also within this album. -
From the album: Deep Sky II
A non cropped image of the NGC891 galaxy. The cropped version of NGC891 is also within this album. The annotation shows the numerous galaxies that are also present within the image - about 11 hours exposure. -
From the album: Deep Sky II
A cropped LRGB image of the NGC891 (aka Outer Limits) galaxy - about 11 hours exposure. -
From the album: Deep Sky II
A reprocess of the data captured in Feb/March 2016 (my original attempt is also in this album). This is an LRGB image with about 6 hours integration time. The main difference between this and the earlier image is that I concentrated on correcting the starfield colours and sharpening the galaxy. -
Thanks !
