Hi guys just uploaded one pic
Moon 4th Day, CCK 21/05/2007 22:27PM
Nikon D50, 200mm zoom, F5.6, 1/15sec, 200 ISO. (with wall support)
unprocessed, just crop to reduce size.
do post coments.
Just a stupid Question... why should one process the image in any software?
(I know it improves its quality...etc... still to know more about it and how its actually done e.g. stacking & stuff.)
I use "Microsoft Office Picture Manager". Can it do miracles....? any links & info?
Thanks & Happy Sky Watching !!!
Moon 4th Day.
Moon 4th Day.
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Good attempt on the moon.
As to why do astrophotographers process images, the level of processing is dependent on the type of image captured and the type of result one would strive to achieve. For the moon, one may like to do a little unsharp masking to 'sharpen' the moon and enhance terminator details. At the same time, one has to be careful not to overdo this, otherwise it will look like a painting. Yet, another respect would be capturing multiple attempts of the same object (or same region) to improve the signal to noise ratio. As one captures and stacks the same object over and over again, the cumulative signal from the object increases, but the noise (been a random property) will effectively 'cancel out'. There are still many other reasons why one should process images, such as removal of noise gradients, light pollution, doing mosaics, even doing water-marking. Here, I am assuming that 'process image' is taken to the understanding that the image is digital 'dealt with' after image capture. Lastly, you may like to downsize the image for comfortable web viewing, which could also be part of image processing. Hope this helps!
As to why do astrophotographers process images, the level of processing is dependent on the type of image captured and the type of result one would strive to achieve. For the moon, one may like to do a little unsharp masking to 'sharpen' the moon and enhance terminator details. At the same time, one has to be careful not to overdo this, otherwise it will look like a painting. Yet, another respect would be capturing multiple attempts of the same object (or same region) to improve the signal to noise ratio. As one captures and stacks the same object over and over again, the cumulative signal from the object increases, but the noise (been a random property) will effectively 'cancel out'. There are still many other reasons why one should process images, such as removal of noise gradients, light pollution, doing mosaics, even doing water-marking. Here, I am assuming that 'process image' is taken to the understanding that the image is digital 'dealt with' after image capture. Lastly, you may like to downsize the image for comfortable web viewing, which could also be part of image processing. Hope this helps!
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weixing
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Hi,
Basically, to remove unwanted components in the image (such as noise), correct the image and get more details from the image.
Registax is a good and easy to use software for planetary and lunar image and it's free:
http://www.astronomie.be/registax/index.html
Happy imaging and have a nice day.
Basically, to remove unwanted components in the image (such as noise), correct the image and get more details from the image.
Registax is a good and easy to use software for planetary and lunar image and it's free:
http://www.astronomie.be/registax/index.html
Happy imaging and have a nice day.
Yang Weixing
"The universe is composed mainly of hydrogen and ignorance."
"The universe is composed mainly of hydrogen and ignorance." Hi Weixing, thanx for link...downloaded with pdf, let me have hands on :roll: & c if i can handle it.
Hey Remus, thanx too... 4 explanation, visited ur web site...gr8 work !!!
Q) so, if i stack more frames of above pic or use Wavelet effect in REGISTAX, it can improve the image clarity or sharpnees....right?
But how do u decide on how many nos of frames... or the more nos the better effects/result!
Have Clear Skies & gud day!
Hey Remus, thanx too... 4 explanation, visited ur web site...gr8 work !!!
Q) so, if i stack more frames of above pic or use Wavelet effect in REGISTAX, it can improve the image clarity or sharpnees....right?
But how do u decide on how many nos of frames... or the more nos the better effects/result!
Have Clear Skies & gud day!
-
weixing
- Super Moderator
- Posts: 4708
- Joined: Wed Oct 01, 2003 12:22 am
- Favourite scope: Vixen R200SS & Celestron 6" F5 Achro Refractor
- Location: (Tampines) Earth of Solar System in Orion Arm of Milky Way Galaxy in Local Group Galaxies Cluster
Hi,
Anyway, remember to use Mirror Lock-up to prevent blurring due to vibration of the Mirror Movement.
Have a nice day.
Basically, yes... as long as the image is not over expose. But more frame will produce better result.so, if i stack more frames of above pic or use Wavelet effect in REGISTAX, it can improve the image clarity or sharpnees....right?
Basically, as many as possible, so that you'll get a high signal-to-noise ratio. For planetary especially Jupiter, you can only capture up to a point where rotation of the planet become visible. That's why planetary and lunar imaging is best to use a camera with video capturing capability, such as a WebCam.... so that you can capture hundreds or even thousand of frames in a short time for processing.But how do u decide on how many nos of frames... or the more nos the better effects/result!
Anyway, remember to use Mirror Lock-up to prevent blurring due to vibration of the Mirror Movement.
Have a nice day.
Yang Weixing
"The universe is composed mainly of hydrogen and ignorance."
"The universe is composed mainly of hydrogen and ignorance." no, this is not always correct. Depending on the current prevailing seeing conditions, stacking high numbers of lunar images via Registax will not always yield pleasing resulting image. This is because if you are imaging with the presence of high turbulence, the overall effect would albeit cause a smoother image (due to higher SNR) but lower effective image resolution due to smearing. Consequently, if one were to image the moon during periods of good seeing, you do not neccessary need to stack so many images. In this case, I am assuming that Sandeep is using DSLR raw images which can be intensive computing for REGISTAX for high number of stacks. The optimum number of stacks for a specific object varies according to seeing conditions, and not just keeping in mind the resultant image not being over saturated (overexposed). For the benefit of others reading this thread in their planetary or lunar imaging applications, this is the case for web-cameras as well. Usually upon capturing AVIs of the lunar surface, it is wise to choose the best quality subframes (stable seeing conditions) and stack these good ones...30-50 will be fine. Sometimes, under exceptional steady conditions 10-20 will suffice.
The result would be a smooth yet sharp image. Yes, one can use wavelets to sharpen the result, but you may think of wavelets like 'eating fast food'. Too much of it, it becomes ring-like, and layered. Use in moderation. It is still better to take care in frame selection and stack wisely. Yes it is more time consuming, but the results are certainly worth admiring.
In summary, the factors that influence the amount of stacking will depend on seeing conditions, type of object, desired SNR, and sky transparency (how clear and cloud-free the sky is). There is the last point to note which is applicable to planets, which is the rotation rate of the planet which limits how many stacks one is able to achieve.
The result would be a smooth yet sharp image. Yes, one can use wavelets to sharpen the result, but you may think of wavelets like 'eating fast food'. Too much of it, it becomes ring-like, and layered. Use in moderation. It is still better to take care in frame selection and stack wisely. Yes it is more time consuming, but the results are certainly worth admiring.
In summary, the factors that influence the amount of stacking will depend on seeing conditions, type of object, desired SNR, and sky transparency (how clear and cloud-free the sky is). There is the last point to note which is applicable to planets, which is the rotation rate of the planet which limits how many stacks one is able to achieve.
-
weixing
- Super Moderator
- Posts: 4708
- Joined: Wed Oct 01, 2003 12:22 am
- Favourite scope: Vixen R200SS & Celestron 6" F5 Achro Refractor
- Location: (Tampines) Earth of Solar System in Orion Arm of Milky Way Galaxy in Local Group Galaxies Cluster
Hi,
By the way, I think there is a 1000 frames and some memory limitation in Registrax, so you can't really stack too many frames if your image resolution is too high and you are using those lossless image format.
Also, Registrax don't support Nikon RAW format, so you need to convert into other image format if you shoot in RAW, such as tif.
Happy imaging and have a nice day.
By the way, I think there is a 1000 frames and some memory limitation in Registrax, so you can't really stack too many frames if your image resolution is too high and you are using those lossless image format.
Also, Registrax don't support Nikon RAW format, so you need to convert into other image format if you shoot in RAW, such as tif.
Happy imaging and have a nice day.
Yang Weixing
"The universe is composed mainly of hydrogen and ignorance."
"The universe is composed mainly of hydrogen and ignorance." actually, when it comes to raw data fed into Registax from DSLRs..there is may not be a very important need to have it in raw form. Often JPEGS are fine already, unless in a puristic view, you have to use raw, in cases of large printouts or presentations, etc. BMP will do fine as well and TIFF will do great but please take note that Registax do not accept 8bit TIFF files for stacking. 16-bit TIFF files are ok for this. This was the case for earlier versions. Have not verfied this in version 4 yet.
