dark-bias-flat subtraction

[jonnydreads]

hi all, 

I'm about halfway through ''making very photon count''... although not the lightest read I've ever read, some parts of it, maybe over 60% has ''gone in''.....

I've read and re-read about dark frame, bias frame and flats subtraction, the author says that these should be subtracted from the ''lights'', I think this is just a word he is referencing for the word ''subs'' which I now understand........ anyway, he only mentions that this must be done but not how to do it, is it a case of reading on or have I missed something......

I am feeling a little overwhelmed by the amount of information I'm wanting to absorb, Im also wondering if maybe I should go to my local astronomy club and meet people to see it happen hands on... I am an engineer and have always learned things so much better seeing it, rather than from a book.... 

I have many questions but don't want to crash this website ?

 

thanks in advance, jon 

[alacant]

10 minutes ago, jonnydreads said:

local astronomy club

Hi. Highly recommended. It is so much easier that way. You also get to see and have hands on experience of any gear you have in mind before you buy. Between them, they'll be able to put together just about anything you can imagine. You'll be up and running in a fraction of the time and if you have a problem, you'll be in contact with those who can sort it out live and in person

Just bear in mind that everyone will have their own ideas on what's best, but none of them know what's best for you;)

HTH.

[mikeyj1]

take a look here...

DSS has a good help file with pictures ?

http://deepskystacker.free.fr/english/index.html

Calibration: how to use dark, flat and bias frames

 

[FaDG]

1 hour ago, jonnydreads said:

I've read and re-read about dark frame, bias frame and flats subtraction, the author says that these should be subtracted from the ''lights'', I think this is just a word he is referencing for the word ''subs''

Hi Jon, 

"lights" is, as you imagined, short for "light frames". 

You're lucky to start today with DSS which is very intuitive and almost full-auto! I second mikeyj1 to look at the tutorial. 

As an engineer myself, when I started using "IRIS", quite complicated and with console interface, I found a big help in Jim Solomon's "Astrophotography Cookbook" (Saratogaskies), a Google search will yield the result. 

It explains VERY clearly all the steps from setup to imaging, to processing workflow. And while you'll now want to use DSS (freeware and intuitive, no valid reason not to use it!), the theory behind for calibration and stacking is the same. 

Fabio

 

[wxsatuser]

8 hours ago, jonnydreads said:

I've read and re-read about dark frame, bias frame and flats subtraction, the author says that these should be subtracted from the ''lights'', I think this is just a word he is referencing for the word ''subs'' which I now understand........ anyway, he only mentions that this must be done but not how to do it, is it a case of reading on or have I missed something......

The master dark and bias are subtracted but the lights are divided by the master flat.

Software like DSS will do everything for you, just put the files in their relevant places.
DSS will even prompt what the best settings may be, looks daunting at first but soon becomes second nature.

If you get stuck someone on here will guide you through it.

[jonnydreads]

Thankyou all. I might buy myself a cheap laptop with windows purely just for astro. Currently I have a Macbook and dss doesn't support it.... I'very downloaded a program called Keiths stacker but there are others although I'd prefer dss....... plus I'm hesitant to take the Macbook outside for more than an hour because of the dew. To be fair I'm a way off yet equipment wise too.

Many Thanks Jon 

[FaDG]

Don't know Macs, but I wouldn't worry toooo much about dew. You might want to give a look at this thread: 

 

[ollypenrice]

You would have a greater choice of software running Windows. If going for a cheap PC don't skimp on USB ports because hubs can be bad news.

Olly