beautiful photographs brother
Photography anyone?
- Thread starter sound1
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arunvenkats
Active Member
Thanks
Regarding deepsky astrophotography, there are 3 phases
1. Data acquisition
2. Image stacking (combining multiple exposures into one long exposure)
3. Image processing
The first phase is data acquisition. Deep sky objects are very very dim. Many of these objects are rather large, but dim. For example the Orion nebula I shared is actually a little bigger than the full moon, but is so dim, we cannot see with our naked eyes. Dim objects require long exposures to be captured by the camera's sensors. 4-12 hours of exposure is common based on how dim the object is. We cannot take very long exposures with a regular tripod or telescope mount because of earth's rotation. If you point your camera to a star and expose it for long time, the star would have "moved" away because of earth's rotation (same reason why the sun, moon and stars rises in the east and sets in the west). We are constantly rotating on the surface of the earth. To compensate for this rotation, we need a "tracking" mount which will keep pointing the camera to the same location despite earth's rotation.
No tracking mount can track forever and cameras have their own maximum exposure times. So we do what is called as stacking. Take multiple long exposures and combine them together using a stacking software. For example, take 100 5 minute exposures and stack them into a single 500 minute exposure. Each 5 minute exposure records the photons for 5 minutes. Even after 5 minutes, if we open the image, it is not possible to see the object because it is so dim. We need to "stretch" the histogram to see the object. Just like audio noise, we have different types of noise associated with image acquisition. And signal to noise ratio SNR is very low because the signal is so faint. Stretching with noise make the image very bad. Stacking allows us average out the signal, reduce noise and increase SNR substantially.
Even after stacking, the resultant image is just black because of how faint the objects are. Making the object pop out is half science half art. We spend many hours processing the image. Stretching the histogram and then doing a variety of image processing steps to get the final image.
Regards,
Arun
This is beautiful
prateekatasniya
Well-Known Member
OMG
This is nothing short of a piece of art !!!
Do you sell the photos you take ?
stunning !!!
Lovely pictures boss!
arunvenkats
Active Member
Thanks!OMG
This is nothing short of a piece of art !!!
Do you sell the photos you take ?
stunning !!!
No... this is just a hobby of mine. And these pics would be no match to some amazing amateur astrophotographers in India itself. The community is very small and niche though.
Vivek Batra
Well-Known Member
Helsinki
Vivek Batra
Well-Known Member
Some more
Vivek Batra
Well-Known Member
Vivek Batra
Well-Known Member
Vivek Batra
Well-Known Member
Vivek Batra
Well-Known Member
Great pics Vivek! The last pic of houses with the boats look like a poster colour painting.
Vivek Batra
Well-Known Member
Thanks Sir, that's Murano Island Italy, went there just to take these houses photo
Sean de Silva
Well-Known Member
one of my eternal favourites
Great shots. Are these snaps with without CPL filters.
Most of the snaps taken here ( Indian cities ) involving sky are a bit livid (bluish grey), I end up using CPL most of the time.
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