I remember one salesman holding up a 30in print of mostly blue sky to promote the noise figure of the camera his store was pushing that month. For those I'm going to have to use a different camera.Ģ-The blue sky noise is half of what one would expect using a RGB demosaicing filter. This is an excellent starting point for B&W images and a no-go for any false color IR images. Without any post processing it loads up with a perfect 'white balance.' This is caused by the camera's unusual sensor, one that uses a yellow, cyan, magenta demosaicing filter instead of the standard Bayer red, green, blue filter.ĭuring the camera's internal calculations to create an RGB image that can be displayed on normal monitors several things happen.ġ-The camera creates identical RGB channels from the internal IR RAW values. And yes, the much simpler RT workflow that produced these little masterpieces is worth blogging and bragging about.Īlthough I didn't highlight it, up at the top you can see this is a tif file. I was about to jump into the discussion and shout out all the ways RawTherapee works better, when I thought it wouldn't hurt to process an IR image to check that I knew what I was taking about.Īfter searching around in my backup folders- I had vaguely remembered taking a infrared set three or four years ago-I found these images. The thread that caught my eye was on Lightroom, infrared images and some over complicated problems you face using that editor. So I was more interested in seeing how flickr's new interface worked when I happened to visit the discussion area in flickr's Digital Infrared group three day ago. Learning the ins and outs of IR photography wasn't going to teach me anything I didn't already know. Rather it because I spent multiple years of my working life designing, building and servicing unusual and very expensive infrared instruments. Not because I don't enjoy looking at them.
#Rawtherapee 4.0.11 download#
To download your comparison image pick your camera in the review pages, go to the sample tab and then the sample image page.I've never been that wild about taking infrared images. And they did things right from the start, controlling details, such as consistent lighting, needed to create reference images that highlight real differences between individual camera brands. They have created a massive data base of reference images going back to the days when a 2 megapixel camera equaled a $1000 investment. Imaging Resource is the place to go for your comparison images.
#Rawtherapee 4.0.11 how to#
I've already posted a tutorial on how to create a noise profile in ImageJ so I won't repeat the steps here. Here is the workflow I used to work out the answer by using a comparison image, RawTherapee and ImageJ Was his camera's S/N ratio within 'spec'? RawTherapee has great noise reduction tools but there are limitations. Our new user picked the right place to fix his noise problems even though his expectations were originally too high. Since they also pack about 12 megapixels into their little sensor-lets say the trade offs are not favoring S/N ratios and low light performance. Those types of cameras have little sensors since, among other things, their light weight and inexpensive super zoom lenses only make little circles of focused light. A new user had bought a 'bridge' camera or, as I used to call them before marketing folks invented the name, a super zoom. But your camera should be close or you do have the right to demand your pixel peepin' refund. Any marketing manager worth his corner office will make sure the cameras sent to review sites were hand picked for performance. Complications on top of complications.Ī more reasonable question would be "Is my camera as good as the camera that was used to take the photos for the review I read on my favorite photo site? The one that convinced me to buy the camera?" Photon shot noise, addition in quadrature, Poisson statistics-those sort of things.
Physics-wise, S/N ratios are complicated. Or, to be more charitable, it might be because accurately measuring a camera's S/N ratio takes more than a look at a computer screen? Why? Maybe it's because some of us meany pixel peepers might take the number seriously and start demanding refunds. Sorry, camera manufacturers don't spec their noise or more accurately their signal to noise ratios. Point to where that is printed on the camera's spec sheet, you demand.
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