6 or 12 MP RAW

It this graph from Phil's tests on noise in various cameras http://www.dpreview.com/forums/read.asp?forum=1020&message=3333944 , he talks about a 12 MP RAW and a 6 MP RAW file. The EX software allows converting to all formats much like in camera processing can do but which is the most real/native and then, which is the best. And finally, why are so many people shooting 3024 x 2016 format. Would I not be better served with the max I can get out of the CCD.
Rinus of calgary

Rinus said:

It this graph from Phil's tests on noise in various cameras
http://www.dpreview.com/forums/read.asp?forum=1020&message=3333944 ,
he talks about a 12 MP RAW and a 6 MP RAW file. The EX software
allows converting to all formats much like in camera processing can
do but which is the most real/native and then, which is the best.
And finally, why are so many people shooting 3024 x 2016 format.
Would I not be better served with the max I can get out of the CCD.
Rinus of calgary

Click to expand...

Hi Rinus,

There is NO native 6Mp image from the S2. The 6M photosites of the Super CCD are arranged on a 12M square grid in a diamond pattern. In other words the native image size is 12Mp but only half of the pixels have an actual photosite measuring light. The other "missing" pixels have to be interpolated to get the native image. The 6Mp (and smaller) image that the S2 will write is a reduced version of the original 12Mp interpolated image. To get a 6Mp image it is a reduction to 70% of the pixels on either axis - probably done in-camera using standard image reduction techniques. What this means is that for every 10 pixels along a row in the native 12Mp image there are 7 "contrived" or reduced pixels in the 6Mp image. (1 divided by the square root of 2 is about 0.7) If you shoot RAW you will always get the the true "negative" of the image. If you shoot 12M fine you are getting the in-camera interpolated native image - which can always be derived from a RAW file. If you shoot 6M fine you are getting in-camera processing to interpolate the 12M image which is then reduced in-camera to a 6Mp image. To shoot anything other than RAW or 12m Fine jpeg is "crippling" the resulting image resolution to some extent. RAW will always give you the best long term source "negative" which can be used for different styles of post processing. For example, look at the development of the QImage converter. Who knows what other (better?) image interpretation software may come along in the future and alow you to re-visit your favourite shots?
--
Doug Jones
Canberra
http://www.panamagic.com.au

Doug Jones said:

. . . . . To shoot
anything other than RAW or 12m Fine jpeg is "crippling" the
resulting image resolution to some extent. RAW will always give you
the best long term source "negative" which can be used for
different styles of post processing. For example, look at the
development of the QImage converter. Who knows what other (better?)
image interpretation software may come along in the future and alow
you to re-visit your favourite shots?

Click to expand...

Don't forget that if you are worried about the storage requirements of RAW files that you can use lossless compression on the files before committing them to a CD. Using WinZip (or similar) compression utility a 12.5Mb raf file will compress easily to about an 8Mb zip file so about 80 to a CD? This compares to the average 4.5 mb of a 12M Fine Jpeg.
--
Doug Jones
Canberra
http://www.panamagic.com.au

Member said:

The EX software
allows converting to all formats much like in camera processing can
do but which is the most real/native and then, which is the best.
And finally, why are so many people shooting 3024 x 2016 format.

Click to expand...

Lets assume a 6MP file would be the best quality you get out of the S2 (less interpolation). Then you have only half the resolution compared to 12MP.

Now ifs you only print at sizes where 6MP has enough resolution then there would be no reason to use the 12MP mode.

But if you want to print larger you need to upsize. So the real question is:

What is better

(a) 6MP converted file and later upsized to 12MP (by some other software)
or
(b) 12MP upsizing interpolation by the RAW converter.

I think that here b wins by a slight margin and the special layout of the S2 CCD might help.

Uwe

Rinus said:

It this graph from Phil's tests on noise in various cameras
http://www.dpreview.com/forums/read.asp?forum=1020&message=3333944 ,
he talks about a 12 MP RAW and a 6 MP RAW file. The EX software
allows converting to all formats much like in camera processing can
do but which is the most real/native and then, which is the best.
And finally, why are so many people shooting 3024 x 2016 format.
Would I not be better served with the max I can get out of the CCD.
Rinus of calgary

Click to expand...

Thanks to both of you. I was already shooting the RAW 12 MB image because I can certainly see a difference. Many people were looking for a CCD that gives these massive files but most people seem to reduce the camera to 3024 x 2016 without ever even thinking about what a 71 MB image could really be like. What a waste.
Thanks again

Rinus said:

Thanks to both of you. I was already shooting the RAW 12 MB image
because I can certainly see a difference. Many people were looking
for a CCD that gives these massive files but most people seem to
reduce the camera to 3024 x 2016 without ever even thinking about
what a 71 MB image could really be like. What a waste.
Thanks again

Click to expand...

I certainly agree there Rinus - what a waste shooting at anything less than 12Mp images (either raw or jpeg). Who knows when you will get that prize winning image, and if your negative is only a "crippled" 6Mp jpeg, your enlargement possibilities are more limited. But if you only ever print small then I guess you don't need it. My Epson large format printer has a base working image resolution of 360ppi - the full resolution of the printer is used for dithering the colours and image. This means when I print a batch of 6x4 proofs good old QImage has to reduce the image resolutions down using downsizing interpolation from about 720ppi to 360ppi to suit the printer driver. Throwing away resolution??. Nevertheless the 6x4 prints are far better than any I ever got from film and a typical processing lab.
--
Doug Jones
Canberra
http://www.panamagic.com.au

So it is still daylight on your side of the world while we are about to go to bed. This internet is truly without borders.

My friens has a new Epson 7600 and has been doing some tests. he finds very little difference between 300 dpi image files and anything larger. Is there some good reason you use 360 dpi? I know that the printer needs to work at multiples of 360 but is the image file part of that need?
Rinus of Calgary

This is one thing that puzzled me when I read the S2 review, Phil said that he expected most people to shoot at 6mp anyway "[...] it's clear to see that the 6.1 mp mode is the way to go." In all honesty Phil most likely refers to 12mp JPG vs. 6mp JPG but even then, I would still go with the highest out-of-camera resolution. Interrestingly later he confirms that the 12mp indeed resolves more than the 6mp (Abs. res. 1800h/1700v at 12mp vs. 1650h/1400v at 6mp, this is a difference of 9% horz and 21% vert, far from being negligeable.)

The noise is a tad higher in 12mp mode apparently but for most shots it should absolutely not be visible (i.e. well lit, sharp shots). And more over, a downsampling in PS would do the same smoothing of noise, so nothing is lost.

Anyway, as I am still waiting for my S2 to arrive, I can only theoretize here but I anticipate I will most likely shoot either RAW or 12mp JPG (depending on the subject). Most of us will use 512MB or 1GB storage and most have laptops or digital wallets, so why bother saving a few MB of storage and later regretting it? It feels like penny-wise and pound-foolish to me...

--
ludo ~ http://hauduc.net

Rinus said:

So it is still daylight on your side of the world while we are
about to go to bed. This internet is truly without borders.
My friens has a new Epson 7600 and has been doing some tests. he
finds very little difference between 300 dpi image files and
anything larger. Is there some good reason you use 360 dpi? I know
that the printer needs to work at multiples of 360 but is the image
file part of that need?
Rinus of Calgary

Click to expand...

Yes, still daylight, and reading the forum instead of doing the work I should be!!

On the point of image print resolutions - A few months ago I had a prime image for some print tests. It was a shot of a friend wearing a very fine pinstripe shirt - blue and white. I printed this at a wide range of image resolutions just allowing the printer driver to do the necessary up-resing to its working 360ppi. Images printed at 240 and 360ppi were excellent. When printed at 300ppi the pinstripes had incredible moire making for a completely unusable print. This occurred for any resolution midway between the "sweet" resolutions - that is, any even divisor of 720 - 2=360, 3=240, 4=180, etc. I think the reason for this is the interpolation methods used by the printer driver which seem to do a better job when you are on an even grid basis. When you use QImage for printing you will observe that, depending on the parameters you chose, it will re-interpolate the image resolution using lancos (by default) to 180, 240 or 360 for wide format, and 720 for the latest 2880 res consumer model Epson printers. Lancos probably does a better job of resing up than bicubic so you may not get the same moire effects but I haven't checked this by printing the pinstripe image with QImage (yet). If you check out the Epson 9000 Yahoo format you will find plenty of historical discussion on print resolutions and the consensus (I believe) is that 360, 240 or 180 is the way to go and that 300 should be avoided. I have found it un-necessary to res up images before printing if I stick to the sweet numbers as the Epson drivers do a better job and I don't have to handle impossibly large image file sizes. (I do a lot of panorama printing typically 18x60 inches or larger).
--
Doug Jones
Canberra
http://www.panamagic.com.au

Some think you even get good results if you go down to 240DPI. And before I upsize the image I even accept 180DPI (all on an Epson 7500).

Uwe

Rinus said:

So it is still daylight on your side of the world while we are
about to go to bed. This internet is truly without borders.
My friens has a new Epson 7600 and has been doing some tests. he
finds very little difference between 300 dpi image files and
anything larger. Is there some good reason you use 360 dpi? I know
that the printer needs to work at multiples of 360 but is the image
file part of that need?
Rinus of Calgary

Click to expand...