In a recent post in the Google Photos blog ("Picasa" blog) the raw image support of Picasa was explained. But it doesn't really explain whats going on IMHO, and why Picasa is nothing more than a quick (I'm not saying "...and dirty", okay:-) "raw viewer".
First, Picasa does NOT support every raw file. With each new model, camera vendors (have to?) slightly tweak their raw format - the file extension is the same, but the format is slightly different. Picasa works with the raw files from the D70, D80, D200 for example, but it does not support the raw files from the D300 as I write this. There's a solution for that: convert the files to Adobe's DNG (digital negative) format. I've tried it, it works. The converter is free (the download is available for Windows and Mac) and Adobe is very fast in adapting it to new raw formats.
Now, back to the meat of things. The main reason to shoot raw is to stay in control in the conversion process, like, how much contrast do you want, how much highlights, do you want to preserve every detail in the shadows or rather drown them... that sort of thing. But you can adjust these things in Picasa later all right?
Well, partly... Picasa is an 8 bit program. All its edits work on 8 bit image data. But the main advantage of raw sensor data is that it contains 12 bit or even 14 bit depth and it contains much more room for shadows and highlights - which you try to bring closer together when you manually convert a raw file.
And thats the problem: Picasa's raw conversion is NOT manual. You have NO influence on the conversion. Picasa finds a raw file, it renders an 8 bit version out of that file, and thats it. You're not in control, and what you get is an automatic conversion of your raw data. One of the key advantages of shooting raw is lost.
The edits that you do with Picasa are edits on the 8 bit data. The most obvious problem is the sharpening - Picasa's sharpening function is a very crude tool, you can't adjust it in any way (and I'd rather not use it). But usually, raw sensor data needs a little bit of sharpening, but not the tons of it that Picasa's sharpen tool applies.
Conclusion: if you're shooting raw - good! If you're using only Picasa, you're wasting the potential thats in your images.
Thanks for this - I've been happily using Picasa (with a Canon .jpg only camera), but now have a D300. Want to make sure that sticking with something like Capture NX is worth the learning curve, vs sticking with Picasa (since I do want to take advantage of RAW's capabilities). Reassuring to know that I'm on the right track!
ReplyDeletehow do i know how many bits my RAW image is
ReplyDeletei'm using a tweak to allow Canon PS SD800IS to create them
I'm sorry, I don't know the specs of the raw format of these cameras. I think you're referring to CHDK? They have a website with a wiki, maybe that information is somewhere there.
ReplyDeletehttp://chdk.wikia.com/wiki/CHDK
Thank you for very essential but often overlooked knowledge. Would you please create a posting specifying the essential camera settings for shooting in RAW? I'd like to start shooting in RAW and am curious about things like:
ReplyDeleteWether one should bother to over or underexpose if shooting raw? Would one get a better exposure in RAW if following the traditional approaches of over & under exposing in response to light conditions?
If attempting to create a HDR composite, should one shoot just ONE 'raw' file or is it better to shoot multiples in a range of over & under exposure?
Thank you?
As this post is over 2 years old I was wondering do you know if anything has changed with how Picasa handles RAW.
ReplyDeleteI just upgraded to my first Digital SLR (the 550D) and am resolutely sticking to shooting in RAW. I've only had it for a short while so haven't properly worked out my digital workflow.
At the moment I'm thinking:
Open RAW in Canon's Digital Photo Professional, do tweaks to light levels there and save out as hi-res jpg for web use or tiff for print use. Then open in Photoshop and do all my main post-processing. Finally save jpg to my main photos archive as a completed work.
Being able to handle it all in one place would be nice, but I'm quite sure that Picasa isn't designed for this. However as I use Picasaweb for sharing photos (and a tertiary backup), I don't think I want to drop it just yet.
Anyway, be interested to hear if you know whether Picasa has moved forward at all as a more professional tool or if it's firmly sitting in the consumer snap shot region.
Cheers,
Alex
Not many changes, processing-wise. The sharpening can be controlled much better now, so that's a plus, but the whole conversion is still fully automatic, and the edits in Picasa are done on 8bit material.
ReplyDeleteEven with V 3.9 ?
ReplyDeleteYes, even with 3.9
ReplyDeleteso you mean what picasa actually does to a raw file is to convert it in the first place to a jpeg and only then process all edits on *that* jpeg?
ReplyDeleteYes.
ReplyDelete