ICEINSPACE
 Moon Phase CURRENT MOON Waning Gibbous66.6% Moon Phase...
 The Sun Now

 IceInSpace Canon DSLR 12 vs 14 bit A/D Convertors - Query?
 Register FAQ Calendar Search Today's Posts Mark Forums Read

#1
07-09-2008, 10:39 AM
 g__day (Matthew) Tech Guru Join Date: Dec 2005 Location: Sydney Posts: 2,564
Canon DSLR 12 vs 14 bit A/D Convertors - Query?

Guys I am pondering how easy it is to see the difference between a shot of say a planetary nebulae take with a 10mega pixel DSLR with 12 vs 14 bit analogue to digital converters.

Could someone who has both post a shot or two please. I presume the extra 2 bits giving you 2^2 = 4 four more levels of shade will produce some nice results - I am wondering how nice!

Anyone that could help - greatly appreciated!

Thanks,

Matthew
#2
07-09-2008, 12:30 PM
 Ian Robinson Registered User Join Date: Jan 2007 Location: Gateshead Posts: 2,205
power(2,12)=4096 bits
power(2,14)=16384 bits
difference = 12288 bits

It comes down to alliasing , and how well the digital conversion represents the analog signal. Obviously 14 bit is a lot better than 12 bit.

This might illustrate the advantage of 14 bit cf 12 bit : http://www.earthboundlight.com/photo...us-12-bit.html

Last edited by Ian Robinson; 07-09-2008 at 01:36 PM.
#3
07-09-2008, 01:26 PM
 Craig_L Craig Join Date: May 2007 Location: Adelaide, South Australia Posts: 558
Hi Mathew,

I have both the 400D and the 450D, 12 and 14 bit but the 450 is modded and not the 400 so I don't know how good the comparison would be.

Any targets in mind?

Craig
#4
07-09-2008, 02:20 PM
 RB (Andrew) Moderator Join Date: Aug 2005 Posts: 21,911
Quote:
 Originally Posted by g__day I presume the extra 2 bits giving you 2^2 = 4 four more levels of shade will produce some nice results - I am wondering how nice! Anyone that could help - greatly appreciated! Thanks, Matthew
Quote:
 Originally Posted by Ian Robinson power(2,12)=4096 bits power(2,14)=16384 bits difference = 12288 bits
LOL Matt, 4 four more levels of shade won't make much of a difference at all !!

A 14 bit A/D converter gives you 14 bits per channel (RGB channel) shades of grey.

Ian is correct in what he posted but he means levels not 'bits', so a difference of 12288 levels.

Technically 14-bit A/D conv, means the camera records up to 16,384 grey shades per channel and allows the camera to record images with better and more accurate gradations of tones and colours.
What this means is basically you have a wider dynamic range to play with and ability to stretch the data.

Whether it will make a difference in your astro images in the end basically depends on your skills in processing and the ability of your monitor and printer to display the difference but 14 bits will give you a wider dynamic range to manipulate the data that's for sure.
#5
07-09-2008, 02:23 PM
 g__day (Matthew) Tech Guru Join Date: Dec 2005 Location: Sydney Posts: 2,564
Thanks guys - good thought. On showing a side by side comparison - I'd suggest a target with alot of faint detail or High Dynamic range. So several suitable targets leap to mind - M16, M20 or M42 (Eagle, Triffid or Orion nebulae). A shots between 6 - 12 minutes on each camera would be ideal (so long as light pollution doesn't ruin things) - I'd love to see the difference of 12 vs 14 bit RAW (both before and after image processing). To me the extra stops could be very useful to an astro-photographer dealing with many interesting things that are very faint.
#6
07-09-2008, 02:46 PM
 Terry B Country living & viewing Join Date: Mar 2006 Location: Armidale Posts: 2,759
http://www.astrosurf.com/buil/eos40d/test.htm
He compares the 12 to 14 bit converters. The english version is spread through the page.
#7
08-09-2008, 12:28 PM
 g__day (Matthew) Tech Guru Join Date: Dec 2005 Location: Sydney Posts: 2,564
Very nice find - thank you!

 Bookmarks

 Thread Tools Rate This Thread Rate This Thread: 5 : Excellent 4 : Good 3 : Average 2 : Bad 1 : Terrible

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Beginners Start Here     Beginners Talk     Beginners Equipment Discussions     Beginners Astrophotography General Astronomy     General Chat     Astronomy Books and Media     Star Parties, Club and Community Events     Celestial and Astronomical Events     Observational and Visual Astronomy         Observation Reports     Astronomy and Amateur Science     Radio Astronomy and Spectroscopy Equipment     Equipment Discussions     Eyepieces, Barlows and Filters     ATM and DIY Projects     DIY Observatories     Software and Computers     Mobile Astronomy Apps     Astrophotography and Imaging Equipment and Discussions Images     Solar System     Deep Space     Nightscapes     Terrestrial Photography IceTrade Classifieds     Telescopes & Mounts     Eyepieces     Accessories     Cameras & Imaging Equipment     Non-Astronomy     Trade/Wanted     IceTrade Archives IceInSpace     IceInSpace Announcements     Website Feedback and FAQ

All times are GMT +10. The time is now 09:21 AM.