View Full Version : Image resolution ??
Rosco
18th August 2008, 08:59 AM
OK troops, need a hand here.
Yonks ago I had an interest in film SLR's, so I have a handle (of sorts) on ISO, depth of field, aperture priority and speed priority etc etc.
Always had a yen for the new DSLR jobbies and we recently lashed out on a DSLR and a HD Videocam.
So here's where I need a hand....
1. With the DSLR (14 MP), would fine mode (JPEG) generally give me adequate quality photos. I don't expect to do much printing. Most likely would be viewed as a slide show on a 42" plasma. When set to RAW, the file sizes are humungous and probably of a higher quality than I would need. The camera is a Sony A350, with more bells and whistles than I would have thought possible, so I need to play around quite a bit. But a few tips up front would be a great help.
2. With the videocam (Sony HDR-SR12E), the suggested format is AVCHD.
This is more or less a fait accompli as I don't have Blue Ray which, I gather, you need to view in this format. So ... I can select high quality MPEG2. I gather this only has stereo sound and not 5.1 surround (which I doubt would be an issue in any event, for my ability). Is MPEG2 quite acceptable also? Plus I gather I will find it easier to edit in this mode.
Again, I know I will need to play around with it, but again, a few tips from those in the know up front would be gratefully accepted.
P.S. I will be busy playing, as we're off for another great adventure in a month and I would like to be fairly well up to speed, prior to our departure.
Thanks in advance
Cheers
vnx205
18th August 2008, 09:53 AM
This article might answer your first question about whether you will notice any drop in quality using JPG instead of RAW.
Raw vs JPEG experiment (http://www.ics.uci.edu/%7Eeppstein/pix/rawvsjpg/)
If you google
raw jpg comparison
you will find plenty of other articles which seem to reach the same conclusion.
Some of the warnings about RAW in this article might be relevant.
http://www.kenrockwell.com/tech/raw.htm
dmdigital
18th August 2008, 01:28 PM
Try here: How Big Can I Print by Thom Hogan (http://www.bythom.com/printsizes.htm)
Not a great fan of Mr Rockwell. Generally if you shoot RAW you have more ability to post process and can always convert to JPEG. It's not just a mater of resolution.
The simplest analogy I can think of is a RAW file is like an undeveloped slide poistive, a JPEG is like a developed one. Once the chemicals hit the slide film it locked in what you can do from that point. You could do a lot more if you could go back to the film and redevelop the slide.
JDNSW
18th August 2008, 04:45 PM
Try here: How Big Can I Print by Thom Hogan (http://www.bythom.com/printsizes.htm)
Not a great fan of Mr Rockwell. Generally if you shoot RAW you have more ability to post process and can always convert to JPEG. It's not just a mater of resolution.
The simplest analogy I can think of is a RAW file is like an undeveloped slide poistive, a JPEG is like a developed one. Once the chemicals hit the slide film it locked in what you can do from that point. You could do a lot more if you could go back to the film and redevelop the slide.
It is certainly not just a matter of resolution, any more than just resolution defines the picture quality of a camera. And as said above, the main, perhaps sole reason for using RAW files is so that you have complete control of all image processing. This will allow you to get better, or at least different images than you could get by processing the images from the JPEG.
Having said that, at the resolution of any TV set, starting with a JPEG and processing that rather than starting with a RAW, you are unlikely to see any difference, except perhaps in very exceptional images with , for example, very high contrast. The resolution of the 14MP image is many times what can be shown on an HD TV screen - where differences may show up is in colours and contrasts, but for almost all pictures I would expect them to be hard to see.
Can't offer any help on the video.
John
rmp
18th August 2008, 05:27 PM
OK troops, need a hand here.
Yonks ago I had an interest in film SLR's, so I have a handle (of sorts) on ISO, depth of field, aperture priority and speed priority etc etc.
Always had a yen for the new DSLR jobbies and we recently lashed out on a DSLR and a HD Videocam.
So here's where I need a hand....
1. With the DSLR (14 MP), would fine mode (JPEG) generally give me adequate quality photos. I don't expect to do much printing. Most likely would be viewed as a slide show on a 42" plasma. When set to RAW, the file sizes are humungous and probably of a higher quality than I would need. The camera is a Sony A350, with more bells and whistles than I would have thought possible, so I need to play around quite a bit. But a few tips up front would be a great help.
2. With the videocam (Sony HDR-SR12E), the suggested format is AVCHD.
This is more or less a fait accompli as I don't have Blue Ray which, I gather, you need to view in this format. So ... I can select high quality MPEG2. I gather this only has stereo sound and not 5.1 surround (which I doubt would be an issue in any event, for my ability). Is MPEG2 quite acceptable also? Plus I gather I will find it easier to edit in this mode.
Again, I know I will need to play around with it, but again, a few tips from those in the know up front would be gratefully accepted.
P.S. I will be busy playing, as we're off for another great adventure in a month and I would like to be fairly well up to speed, prior to our departure.
Thanks in advance
Cheers
Resolution is just the size of the image. It has nothing to do with quality. Quality comes from the lens, body and photographic technique.
If you do not intend to post-process your images do not use RAW; in other words, if you want to shoot and view, shoot JPEG, if you want to eke out every last bit of quality and entirely control what the image looks like, use RAW but be prepared to invest in the software and your own time.
I don't know what resolution a 42" plasma would be, but say it was 1600x1200 pixels, that'd be 2 megapixels, so a 2Mp image would exactly fill the screen and look just as good as a 12Mp one, all elsebeing equal.
So to view your 12Mp images full size would clearly require a gigantic screen, and you'd need to stand so far back it would be equivalent to a much smaller one.
So, why bother with greater Mp counts? Print resolution is one, if you consistenly make above A3 prints high resolution cameras are required, but soon you get back into the "it's so big I have to stand a mile back" problem.
The other advantage is cropping. You can take a 12Mp shot and crop it into a smaller one, and it's still say a biggish 8Mp or so in size.
If you have specific questions about the A350 you can post them here.
Don't know about the HD, TV isn't my area.
300+
18th August 2008, 06:16 PM
I always shoot raw on my A100. I don't care about storage as HD and CF cards are very cheap. I have spent less than 10% of the camera cost on storage.
It is an extra step to process, but not a biggie as you always need to resize the image before you email it to people anyway. It has been years since I took an image from a camera and sent it or printed it as it was. If you are opening it up it in an editor it doesn't really make a difference if it started out as a raw or jpeg.
Since I've been shooting RAW I've noticed that there are more images which have recoverable detail in the shadows or highlights. If you shoot jpeg and it isn't quite right then you can only do so much to recover. In raw you have much more latitude. And as you are not editing destructively you can apply more shapening & noise reduction before you start degrading the image.
I find lightroom great for editing & cataloging raw files. It is not very expensive if you can get the academic version (kids in school/uni, etc.). The standard Sony software is OK and google Picasa can also handle sony raw.
As others have said resolution is not a concern unless you take a picture of something far away and need to crop the photo to zoom in. You can do this with a 14MP image and really zoom in and still display 1 image pixel on 1 screen pixel for complete quality. One of my favourite shots was cropped this way and still prints perfectly on A4.
Steve
Offender90
21st August 2008, 03:06 PM
I always shoot raw.
I'd have to agree. RAW takes a bit of getting used to, and the file sizes are greater, but much greater degree of control (and F***up correction) in post processing.
When taking action snaps, it's all about getting the right shot at the right time. You often don't have the time to be checking exposure, whitebalance & other settings, let alone adjusting them. That can all be adjusted in RAW later, as if you took the shot with those settings to start with.
I usually shoot action in RAW and aperture priority (AP) mode, so I can focus on getting the right shot, with only aperture and focus to worry about. Auto exposure is within the "perfect adjustment range" 99% of the time.
And it paid off in other ways more than once. I have in the past shot an entire trip in tungstan white balance mode, (didn't adjust it from the night (or week?) before - who knows). In any case, the photos had a very aged yellow tinge so if it wasn't for RAW, they'd be ruined!... not to mention the flack I'd be coppin' from friends and family.
The other thing I find when taking 4WD snaps, the most important photos (i.e. MINE!) are never taken by me! RAW allows me to correct a lot of the settings retrospectively that I would have done differently.
With Resolution / print size, I find its the sensor's physical size that's more important then the actual resolution - and if you're only displaying on Plasma / LCD, the resolution its going to be 1920 x 1280 at most - little over 2MP. Besides, its amazing what you can do in Photoshop with resizing / resampling. I've blown up an 8 MPix image to 92 Mpix image (1.6m x 1m print) with very little apparent loss of quality.
As for the video, the only word of wisdom I can offer: your camera is likely to have a stereo mic at best, so no need to shoot 5.1 ch audio as you'll only have 2 input channels.
Rosco
21st August 2008, 04:22 PM
Thanks blokes
Heaps of words of wisdom ................ as usual.
Cheers
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