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Showing results for tags 'flats'.
Found 23 results
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Hey everyone, Over the past few days i've been gathering data on M31 due to the battery not lasting long and andomeda dissapearing behind a tree, therefore the mulitple imaging sessions. So far i've been out and me being me, only took dark, bias and light frames for the first 2 sessions but for the last one i also included flats... (The lights all have very slightly different settings cause i have been experimenting slightly... that being 45sec @ ISO 400, 45sec @ ISO 200 and 50sec @ ISO 100) Now DSS assinged all the correct bias and dark frames to the corresponding light frames but becaus -
Hello, when applying the flats taken in my last session (to find out what is causing the strange diffraction spikes) with Siril, the final stacked result still shows the vignetting and the dust spots. I also did the whole preprocessing with Nebulosity, same result. I took the flats as follows: same iso as my subs camera and focus not touched I use a homemade flatbox combined with the a white t-shirt with Ekos took test shots till the histogram was half-way to the left checked all my flats, they all show vignetting and the same dust spots as in my subs
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Hi All, I am posting what I suspect is a newbie mistake question but hoping that someone can assist with the issue of flats. Although I have been fumbling around the sky, taking snaps at leisure, recently I became serious. I have read up about the different calibration files (flats, darks, bias) and they seemed to make sense; different ways to capture the image defects and extract those from the image of the sky. After a few weeks (months) of further fumbling I went back to the very first target to receive my attention, M42 Orion Nebula. In short, I took 20x 30s exposures in LRGB a
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Hi all While I've been largely locked under clouds for a couple of months, I thought I'd write some software that I've been meaning to get around to for a while. I use a standard LCD computer monitor for taking flats. I plug it in to my imaging laptop. I started off using a blank HTML page in a full-screen browser window to provide the uniform grey colour on the display but I needed to vary the brightness of the display for different filters. So, I wrote some software that does it. The software is called Second Monitor Lightbox and is available free of charge from my site (pa -
Hi All, I have recently converted from an old Canon DSLR to a ZWO ASI1600MC-Pro. The individual subs look great with the new camera, but I am having seemingly insoluble problems processing, so I need the assembled wisdom here! The first image shows a single sub on the left (auto-stretched), and the result of stacking some 25 subs on the right, combined with flats. The flats have corrected quite nicely for the dust doughnuts, but given me inverted vignetting. (I should say that I have tried processing with darks and bias as well, but the basic problem of the reversed vignetting remains. Pr
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So after Carole helped me to realise that I was taking my flats wrong, I've reprocessed this image and finally the funny rings have vanished. Original thread TL;DR - I was underexposing my flats, which resulted in failure of calibration to remove vignetting, as well as it introducing weird red concentric oval rings. Last night was supposed to be clear, so I set up in the garden. Cue the Irish weather. I only managed to get PA and focus (you know, the most fun bits) and then the clouds rolled in. Anyway, so instead of imaging, I took a bunch of calibration frames. The setup
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Does anyone seen the new Ikea LED lighting lineup ? They have launched a new LED product, FLOALT, which is some sort of light box and it comes in three different sizes, from which one is really interesting: FLOALT 30cm. Does anyone already acquired it, would this work as a flat box ?
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Hi again! I posted a query about flats a while back, but have now run into a more specific issue so starting a new thread for this. I had a decent clear night couple of days back and a chance to give the ASI1600 a bit more informed testing. Still finding some oddities with flats generally though, so hoping for some further thoughts please. In the past when doing flats with the DSLR, I've pointed the scope at an evenly illuminated area of the ceiling and run off a number of exposures sort of mid-gray middling histo no problems - always worked very nicely. With the ASI1600MM a cou
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I need to get/adapt an ELD for use with my Explore Scientific 80ED and Mak 127 to make Flats. What is the current thinking on the best choice of panels to base one on (uk) and any advise on power supply. Many thanks David
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I have been generally pleased with my Moravian camera and filter wheel. However, I noticed I was getting some very odd results when trying to calculate filter offsets for my autofocus routine. I found that the wheel was not rotating to the filter requested - indeed it seemed random. Of course it was not random .... I have a 10 position filter wheel. However, it seemed that the Moravian Ascom driver was convinced I had a 12 position wheel. To get the Moravian wheel correctly configured, you have to run a configuration program. It tells you to do this in the manual. I just hadn't r
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What sort of exposure length do people use for their flats? In particular with a flat field panel. I'm concerned my Gerd Neumann panel is too bright. He now sells grey filters to cut the light level. I use Skyflats4 to ctually take the flats. My exposures are around 0.03 seconds for LRGB. Is this too short? I'm using a SXVH694. Thanks Anne
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I've had continual problems with reflections in my flats. I have an Atik 383L, an Atik EFW2, and I use 36mm unmounted Baader filters. It seems that when using the camera and wheel 'as intended' I get reflections. I see these especially in my flats, but I think they are there in the images too. They do not calibrate out - I am left with lines in my images and I either have to crop them heavily or use blunderbuss processing techniques, which inevitably leads to some degradation in image quality (and my images are already quite degraded enough). I have posted about this problem before: h
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Can anybody suggest what might be wrong with my flats calibration process? I created a master flat from 40 images taken by placing an ipad over the end of the scope displaying a photo of a featureless wall (maybe not the best method?) A stretched image of the master flat shows a number of very faint dark circles which I think are grease spots on the objective lens of the scope. I can see these clearly when the lens is starting to dew up after an imaging session. Anyway after using these flats in DSS or Atik Dawn, these artifacts start to come through on the processed image, see
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Note sure what to make of this. I was watching a video on improving flats for my WO Star 71 and using CCD Inspector to help with this. I downloaded the free trial and performed a Flat analysis on one of my Flat frames. I was fairly alarmed by the results because when I looked at them in SGP they looked fine. CCD Inspector appears to show at least two issues. One is the centre of optical illumination is quite a way out from the centre of the CCD chip (KAF8300) Also not sure if the high percentages around the image are an issue? Though they seem to be fairly consistent though. Wh
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As this is my first go at doing flats, I am going to go into a bit of detail, as almost any step I have taken in this could be the cause of the weird result I got. I purchased a 10cm circular white ELP (sticky back) which I attached to a circular piece of card. I covered this with a piece of plane white paper (to diffuse the light) and attached a ring of card so that it would sit over my small refractor or camera lens. It is powered through the mains cable. After completion of my lights, I moved the axes of the mount so that the camera lens was pointing vertically, placed the mounted -
Hi All, I have just made myself a light box for doing Flats which on my first play with it last night, seemed to work okay, but I am not sure what brightness / exposure level I should be aiming for? Attached are a few screen shots taken at different exposures (0.2 seconds up to 1.0 second), all taken at the same brightness level. Now, rather than changing the exposure, I can make the lightbox darker or brighter, but I will see similar images to those below. So my questions is, which one of these exposure times is the 'best'? I have included the histogram in each screen shot, as I understan -
I've finally got around to making my flats box. I decided to go for a cylinder rather than the normal square as I thought it would maximize the amount of reflected light and limit any 'dead' areas. I could also use the Celestrons dust cap retaining pins to lock the flats box onto the 'scope. I purchased some of the craft board that has a thin foam sheet sandwiched between two sheets of thick paper/thin card. In order to bend the card into a cylinder, I creased the board every 20 mm by pressing the edge of a steel ruler into the board. It took two of the sheets to make a cylinder big
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Hi all. I've created my own darks library for my ASI1600mm Pro. Various gains and various exposure times all at -10 Celsius. I'm just wondering what people do with them? Once you've taken darks and processed an image you get your master darks. Do you guys just keep the master dark, in a master darks library, or do you process your darks again each time you stack a new image? I'm just thinking to save storage, could I discard the dark sub frames and just keep the masters? I don't want to throw them away if that is wrong though. Also, with this camera I take dark flat
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Hello, i am having so many difficulties as far as i remember to make some nice flats to match my images.For some reason it it impossible for me to find the secret spot in time and adu for my Flats. This is my equipment : Telescope: Redcat 51 Camera: Atik 383l+ mono (i know the shutter problem that's why i always aim for 3sec and above for taking my flats) Filter Wheel: Atik EFW2 (36mm) Filters: Astrodon Ha & Oiii 36mm 3nm FlatBox: Geoptic flat field generator 164mm (dimmable) Image aquire software: APT Tool v3.71 Software: Astro Pixel Processor -
From the album: LightBox 90mm refractor
© SabinFotafotografie
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From the album: LightBox 90mm refractor
© SabinFotafotografie
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Hi all, Last week I made some photos using my canon 500d on fixed tripod, with also the darks and bias. The results were not bad, but no milky way really visible, and I've been trying a little bit to fiddle with DSS parameters, or ACDSee, but no luck. I thought maybe the lack of flats was partially the cause of this, so I made some, yesterday. But probably I haven't understood flats at all, because instead of cancelling the vignetting, it added bright vignetting...... So my question is, if my lights are 30 20sec subs, 1600 ISO, f/4.5 at 18 mm, what should my flats be like? I did 30 subs at 160
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Folloing on from a post I made in early November :- http://stargazerslounge.com/topic/198663-is-this-acceptable-or-only-30-mins-of-data/ I am finding myself frustrated by lack of time and the clouds.... (set up three times last week, clear skies, but by the time it was dark the good ole clouds had rolled in and put paid to another night.. So with the limited time I set myself a challenge to see what I could achieve with only 30 mins of subs, I have included three images of what I have so far. I would be interested to see what others could achieve with the same limitations, so are you up for
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