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Mysterious RAW files.

Jul 17, 2012, 17:50
Post: #1
Mysterious RAW files.
So I've been out snapping away with the Canon, using the histogram in an attempt to balance the exposure, it flashes away when I've really screwed up. And I've learnt that F-stops aren't bigger with higher numbers but are in fact smaller - got to love dummies books they really do explain things that manufacturer manuals don,t. So everything's been go relatively well, or it was until I tried to find the RAW files - the camera's set up to take jepg and raw.
I never got an ESO solutions disk with the camera but I downloaded UFRaw and have got Picasa installed. Now they both say they open raw files, trouble is UFRaw says it can't decode any pictures I transfer to the PC and the pictures that show up in Picasa are all jpegs, no sign of raw files anywhere. So I'm not sure what's going on here, or what I'm screwing up but I could do with those raw files.
I not really sure why I need them, well I have got a vague idea, but everything I read says I should have them as the pictures can be edited into things they never should have been and that kind of brings out the mad scientist in me, cue flashing lights and lightning strikes.Big Grin

Any help with this gratefully received. Cheers.

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Jul 17, 2012, 19:14
Post: #2
RE: Mysterious RAW files.
You should have the CD... or lookup the Canon site, and download the "updates" (which are full blown apps).

To obtain the "raw" files, you should set the "quality" to RAW or L+RAW. You then get IMG_nnnn.CR2 files together with the IMG_nnnn.JPG files. Not all picture management software will copy them to your PC... CR2 files are much bigger than JPEGs (typically 14-15M for your camera). In amateur photography circles some people consider that JPG is for the unwashed masses and that the true experts use RAW. This is mostly false. The folks at Canon (or Nikon/Sony/Samsung/Panasonic) do work out very good compromises. Making your own version of the picture from the RAW file takes time (otherwise, you are using a simplistic process that you can likely obtain from your camera using the proper settings) so very few of your pictures are worth this effort. Usually your venture with RAW files follows this scheme:

- plain ignore them and shoot JPG only
- discover RAW take a couple
- decide to run JPEG+RAW all the time, just in case
- discover that JPEG is good enough for most purposes, and RAW take space (and time to transfer) and use RAW only on some difficult occasions (night shots, etc...)
- (maybe) get really good, take only one definitive shot per day, and use RAW on all.

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Jul 18, 2012, 17:33
Post: #3
RE: Mysterious RAW files.
Thanks for the info.
I think I'm trying to run before I can walk so I'll leave the RAW files alone for the time being as there's no need to make a complicated subject harder. And I'll get a disk from ebay as I've read that the updates for Canon don't work unless there is an installed version of the disk on the hard drive - apparently there is a work around to this problem but it involves writing a new registry entry so I need to make sure I won't screw up my PC in the process if I'm going to try it.

I've still got a lot to learn about exposure levels and the like so that should keep me busy for a while. Many of the pictures I took today, i was wandering around some woods and lakes, came out quite dark. The histogram kept saying that the sky was to bright, grey day but still a bright sky, so I changed many settings in order to compensate and most of the time it didn't work. I've got a feeling it's a problem with the white balance so I'll do like the book says and point the camera at the sky first off and try to set the balance manually.

Off to a fort tomorrow so more experimenting ahead.

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Jul 18, 2012, 21:51
Post: #4
RE: Mysterious RAW files.
Bad exposure has nothing to do with white balance. If the sky is 50% of the picture then of course the non-sky parts are likely to be a bit dark. This is what the exposure bias is meant for (the AV,+/- button). However if your pictures contain more that 1/3 of empty gray sky they are going to be quite dull and depressing...

Setting the WB by pointing the camera at the sky is just making sure the sky will be gray with no hint of blue. If you want a manual WB, shoot something which is guaranteed to be white (print paper, or the lid of a Nutella jar).

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Jul 19, 2012, 17:38
Post: #5
RE: Mysterious RAW files.
I seem to be getting a lot of sky in the pictures, the grey stuff looks bad, the blue good, but I put most of it down to lack of skill and practice. Still, as I've taken approx 300 snaps over the last few days I'm going some way to making up for the lack of practice.

Got some good pics today, mostly heavy guns and walls and buttresses, and some very cool ones from inside a network of tunnels. I turned the ISO right up and disabled the flash. I'm amazed by how well they came out. Even at 0ne eight of a second there was no camera shake but anything below that was a big blur. The light in the tunnels was very dim and in the pics there's this yellow ghostly glow that I'm very pleased with. I'll certainly be able to use those ones for some scene setting.

I'll fire away a some white paper and see how it works out. I did take a snap of my kitchen radiator before I set off, it's bright white, and the shoots from after that seem better than the ones from after firing at the sky. Lots to learn.

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Jul 19, 2012, 20:13
Post: #6
RE: Mysterious RAW files.
The WB should be redone each time, sing the lighting of the scene you want to shoot. No point in doing it too early.

When you shoot grainy subjects such as walls, the noise of high ISO isn't too visible. My personal record is 1/3 of second fully hand-held. But you can also maintain the camera against a wall/pillar for longer exposures. Some piece of heavy cloth (that will often double as headgear (soft hat, cap...)) between the camera and the wall will help keeping the orientation during long exposures(*).

(*) Too shoot in museums, find a lens hood. Maintain the lens hood against the protection glass: the camera doesn't move during the long exposure, and this suppresses all reflections on the glass. The lens hood is also very useful to protect your lens against shocks.

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Jul 20, 2012, 17:29
Post: #7
RE: Mysterious RAW files.
Quote:Some piece of heavy cloth (that will often double as headgear (soft hat, cap...)) between the camera and the wall will help keeping the orientation during long exposures(*).

More invaluable advice, cheers.

I think I've got a lens hood already. I'm guessing it's the plastic attachment that screws onto the lens and look like a..well, rose shape. I was wondering what it was for.

Managed to get the EOS software onto my PC, looks like it's going to come in real useful.

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Jul 20, 2012, 20:12
Post: #8
RE: Mysterious RAW files.
A lens hood is primarily meant to avoid light rays that aren't part of the picture (from light sources on the sides but also from anything with good reflective power such as white walls) from entering the lens and bouncing at random and creating flare or reducing contrast. But they have other benefits...

The petal shaped ones take their shape form the combination of two factors: a cylinder or slight cone section of the plastic (this allows to store the hood by mounting it backwards on the lens), intersected with the required rectangular field of view.

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Jul 21, 2012, 17:28
Post: #9
RE: Mysterious RAW files.
I'll try out the hood, it will be interesting to see what the pics will look like when it's on the lens and when it's not.

Quote:My personal record is 1/3 of second fully hand-held.

I tried a few long exposures today, the best I could do was 1/5 of a second. Caught the rogue below with that one.

   

I'm going to have to practice my rock mode if I'm going to get better than a 1/5th. Big Grin

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