32 bit for hdr

vendeta · 27th February 2007

this might sound stupid to others, but excuse me for my ignorance, how come all my raw files are in 16 bit only when i process them to jpgs? how do u convert them into 32 bit? i'm using an e500.

Blu-By-U · 28th February 2007

is it?

never seems to be a problem. What software are you using?

vendeta · 28th February 2007

Originally Posted by Blu-By-U

is it? never seems to be a problem. What software are you using?

I'm using photoshop cs2 for converting my raw files, any idea?

Nerd · 1st March 2007

If I remember correctly, Jpegs can only store 8 bits for colour data. 32 bits is for HDR and in most cameras, the sensor is unable to store that wide a dynamic range of data, hence it's normally 12 bits up-convert to 16 bits.

I don't see much point in converting 16 bit photos to 32 bit photos since you don't really gain much, and need more processing power / memory when editing the photos. If anyone knows what advantages it might bring (for non HDR purposes) please correct me.

Why do you want to convert your RAW files to 32 bits? Unless you are merging multiple exposures for a HDR image, in which Photoshop automates the process and outputs a 32 bit photo for editing.

nightpiper · 1st March 2007

i have an impression u r mentioning about the color depth per color channel.

8 bits for common use & 16 bit depth for image manipulation.

also i have the impression that DSLR HDR images r nothing but layering 2 or more layers to get the exposure right for hi-lites & shadows. the other native HDR file i heard was from medium format digital backs (well, it comes with a 16 bit sensor to begin with).

did i get the question answered right?

espion · 10th March 2007

In CS2 if you do HDR via the "Merge to HDR" you get an 32bit/channel (not pixel) - ie 32x3 = 94 bit/pixel - intermediate file, which you have to downconvert to 16bit/channel (48bit/pixel) to manipulate in Photoshop, and further down to 8bit/channel, ie 24 bit/pixel to save as a JPEG (the standard for JPEG, ie you cannot have a 16bit/channel JPEG). I dont think there is a native out-of-cam 16bit/channel file output, as DSLRs output at most 12 bits/channel.

27th February 2007	#1
vendeta Member Join Date: Sep 2002 Posts: 251	32 bit for hdr this might sound stupid to others, but excuse me for my ignorance, how come all my raw files are in 16 bit only when i process them to jpgs? how do u convert them into 32 bit? i'm using an e500.

28th February 2007	#2
Blu-By-U Member Join Date: Aug 2006 Location: Selangor D.E. Posts: 1,417	Re: 32 bit for hdr is it? never seems to be a problem. What software are you using? __________________ World thru my lens

1st March 2007	#4
Nerd Member Join Date: Oct 2002 Location: Singapore - Jurong West Posts: 699	Re: 32 bit for hdr If I remember correctly, Jpegs can only store 8 bits for colour data. 32 bits is for HDR and in most cameras, the sensor is unable to store that wide a dynamic range of data, hence it's normally 12 bits up-convert to 16 bits. I don't see much point in converting 16 bit photos to 32 bit photos since you don't really gain much, and need more processing power / memory when editing the photos. If anyone knows what advantages it might bring (for non HDR purposes) please correct me. Why do you want to convert your RAW files to 32 bits? Unless you are merging multiple exposures for a HDR image, in which Photoshop automates the process and outputs a 32 bit photo for editing.

1st March 2007	#5
nightpiper Member Join Date: Oct 2003 Posts: 1,794	Re: 32 bit for hdr i have an impression u r mentioning about the color depth per color channel. 8 bits for common use & 16 bit depth for image manipulation. also i have the impression that DSLR HDR images r nothing but layering 2 or more layers to get the exposure right for hi-lites & shadows. the other native HDR file i heard was from medium format digital backs (well, it comes with a 16 bit sensor to begin with). did i get the question answered right?

10th March 2007	#6
espion Deregistered Join Date: Aug 2005 Posts: 1,533	Re: 32 bit for hdr In CS2 if you do HDR via the "Merge to HDR" you get an 32bit/channel (not pixel) - ie 32x3 = 94 bit/pixel - intermediate file, which you have to downconvert to 16bit/channel (48bit/pixel) to manipulate in Photoshop, and further down to 8bit/channel, ie 24 bit/pixel to save as a JPEG (the standard for JPEG, ie you cannot have a 16bit/channel JPEG). I dont think there is a native out-of-cam 16bit/channel file output, as DSLRs output at most 12 bits/channel. Last edited by espion; 11th March 2007 at 12:12 AM.