At least, it wasn't noise as we usually mean it. I posted some flower close-ups to Shot of the Day some months ago, and folks saw bad graininess in dark areas in the background. They also saw white flecks on the flower petals. Well, the white flecks, if they hadn't been real, would have been noise. Since the flecks were real, possibly pollen, they weren't noise. My attention was directed to the graininess - and then I saw what the problem. It was even called noise, and I was asked what camera I had used, and a comment was made that it looked like I'd shot at ISO 3200 rather than the ISO 800 I claimed. In another context recently I noticed extreme graininess in some slide copies I was working on. It turned out to be due to trying to spread out a narrow range of red, blue, green, or "value" to the full jpeg 8 bits. This will invariably lead to graininess, looks like to me, as the intermediate ranges cannot be rendered. Going back to my original photo in raw format, I compared it to the photo I posted. The raw photo had no graininess. The graininess was an artifact either of my processing, or simply of the conversion from raw to jpeg. I checked by converting the raw to jpeg again, making sure to compress the image as little as possible, and I see no graininess in the result. I then spread a narrower range of value to the full range, and look how much graininess showed up! Here's a small piece of the original photo, converted to jpeg with minimal compression: [/url] testNoise by MechDoc, on Flickr[/IMG] And here is the same shot after spreading a smaller range to the full 8 bits: [/url] testNoise02 by MechDoc, on Flickr[/IMG] So, while Sony cameras may be slightly less resistant to noise, as reviews indicate, this was not a noise problem at all. Graininess and blotchiness is most likely to be due to compression issues. I'm relieved.
Don't know about your monitor settings, but there's definitely quite bad color- and luminance noise in the first photo and the second one is really not looking good. Are you working with a calibrated monitor would be my first question? What software are you using for RAW conversion would be the second one?
Sorry for the double post, but I checked out the photos you've posted on the "Photo of the day" - thread and there's something I noticed quite clearly. There seems to be a general lack of black in your photos. I think you are pushing the photos too far (again I suspect this to be due to uncalibrated monitor), which will definitely cause noise in an otherwise noise-free image. What I mean by that is that you should let the blacks clip a bit since with most images having pure black in some parts of the image is beneficial. Also use the lowest possible ISO when taking the photos and check out also "Exposing to the right" from Luminous Landscape, clicky here. That'll probably explain the "blotchiness" in your photos as well (lack of tonal values which comes really bad with compression).
This was posted just now on the Luminous Landscape and it's definitely worth the read. Have you looked into this problem yet btw? And how about other people, what do you think about this issue?
I have to agree, there is indeed noise/grain/dots/whatever present on your first picture. FWIW, I run 2 calibrated 2001FP's, maybe you need to calibrate your monitor?
maybe you should include the same snipped from the uncompressed JPEG (considering the comments above going into grain and monitor settings again)
Looking at the histogram, there's no black in the picture at all - the blacks are not black. The image as a whole also has a very yellow cast. I had a quick play in Photoshop and came up with this... hope you don't mind
Guys! I guess I implied that the first photo here, having been blown up to a faretheewell, and maybe compressed some more (I don't remember exactly, but I may have compressed the jpeg to post here further than the "original" compression from raw to jpeg) showed no graininess. That was not at all what I meant. The raw photo I looked at had none. The point I was making was that compressing the info from a raw photo into a jpeg or tiff, without compression, can produce grains. I believe I said much the same thing that Darkened said, although perhaps he said it more clearly. That was illustrated by how much grainier the second photo looked than the first, which was my point. I never thought the first photo I showed was free of grain, and I certainly did not think the "black" areas were solid black. My monitors do not need fixing. The "black" areas were dimly lit because of the distance from the flash, but were not black. I need no information about how to make them black, or on how to blend out graininess. I might not quite be an expert photo doctorer, but I'm getting there. I did not say that the first photo was great; it was only to show by contrast with the second shot how compressing into fewer bits introduces graininess. When I first posted the original first photo and got the reply that it was noisy, I also got pointed questions about what camera I was using, because the photo was full of noise. Like I suspect most non-photographers would, I had looked only at the flowers and leaves, not at the "black voids." When I understood what the first commentor on noise was talking about, I saw the little green dots in the "black," too. And I did figure it was digital noise from the camera sensor, because I'd inadvertently left the camera set at iso 800. My post here was to say that there was no such noise in the raw photo, that it had all been introduced by post processing, a part of which was compressing the photo by jpeg or tiff, and further that lossless compression produces more graininess than jpeg with some compression. If your only intention was to help me, then I thank you for your efforts. Some of the "help" sounded quite condescending.
I'm confused about a couple of things: 1: What are you trying to explain? From what I understand the first picture in your post was supposed to be a "good" example, while the second was supposed to be a "bad" example due to jpeg compression. However, the first picture doesn't look good at all (NOT talking about composition). It's still very grainy, especially in the black areas. If this looks like a smooth black on your monitor then there is a problem somewhere. I guess that's what everybody (me included) thought. 2: Who was condescending? All the posts seems to be genuinely helpful (Maybe except mucgoo's post)
It was not that the first picture in this thread was good. It was that further compression made it worse, as in the second shot. The graininess in the first shot was also due to compression. Maybe I was too sensitive about the condescension. Remember that my initial posting of what I thought was a good, sharp closeup elicited questions about my camera, because photo guys found graininess in dark areas I hadn't even looked at. Later I discovered that the graininess was not noise from the camera's sensors, but was introduced when I compressed the image from raw. I wasn't clear that the first photo in this thread still had imperfections (it, too, was compressed by jpeg for display here), it was by contrast with the second photo that I thought I demonstrated how compression had caused the "noise" in the first place. And that brought comments about how I needed to check my monitor(s), along with an explanation of how compression can cause "noise." Sorry if I have been too sensitive.
Ah. I see. Out of curiosity, exactly how do you compress to jpeg? Using photoshop, when I set compression to as high as possible I never get that kind of noise. Often jpeg compression causes a horrible "mosaic" in the picture, but not grains. I thought all software did it more or less the same, but if that grain come from compression it seems like different software do it slightly different. It must be said that I haven't done much research into jpeg compression. I usually set it to highest quality anyway.
I have several different programs to compress from Sony raw to jpeg. One is from Sony, of course. I frequently use IJFRWin64 for bulk conversion. If I select a bunch of raw photos in Windows Explorer, then right click, one of the options is to convert all to jpeg, extracting to a new folder, in various sizes. It's extremely quick, and preserves the EXIF data so that I can use my GPS program for locating the photo geographically. I don't think this second program gives me any choice about the amount of compression, beyond setting the number of pixels. My main photo editor these days is GIMP2. I find it slightly more powerful than Paint.net; both are free; both allow layers, masks, and fairly powerful selection tools, but I decided GIMP was a little more powerful - although with a steeper learning curve. I'd be surprised if it didn't have just about all the capability of Photoshop, except that it doesn't handle hdr without some plug-ins. And a plug-in allows GIMP2 to read my Sony raw files, albeit the program is slightly unstable - this instability might be related to file size, as it seems worse if I load in more than a couple of photos at a time. Which brings me finally to saying that GIMP has "lossless" jpeg compression among its jpeg options. I put that in quotations because the raw photos have greater bit depth, so any jpeg will be compressed, but I infer that no blending occurs. I think it's the lack of blending with this (somewhat rare) version of jpeg and tiff that can lead, with compression from raw, to blotchiness in the photo. Sorry if this reply dragged on. I tend to be pedantic.
