I am going back to RAW & manual.

[Manfred M]

Ted - to some extent we are splitting hairs here. (Don't we always do that?)

The Sigma cameras use the Foveon sensor (I believe Foveon Inc was bought out by Sigma) and is unique versus what other camera manufacturers use (i.e a sensor with a Bayer filter). It uses an approach that is more akin to the way traditional colour print film worked, where each x,y coordinate on the sensor also has an associated R, G and B value. No fancy data reconstruction algorithm is required, due to the design of the sensor. I remember reading some articles that Foveon put out when they first introduced this sensor as it definitely solves some of the issues associated with the Bayer filter approach.

Unfortunately, it does not bring clarity to the discussion, as it represents such a unique, niche approach. The fact that no other camera companies use the Foveon sensor suggests to me that this benefit is is outweighed by the liabilities of this approach. You often bring these up yourself. Noise, poor low light performance, etc.

Brian's Sony uses a Sony sensor with a variant of the Bayer array, so as George points out, this data cannot be directly displayed as an image without some level of processing to turn the data into a form that can be displayed. In fact, the vast majority of the members use a similar sensor, so bringing up Sigma cameras is really not adding any value to the discussion.

[george013]

If I was being cheeky I could post a shot of some RAW hamburger. But on a slightly more serious note any collection of photons on whatever surface you care to name that can be used to represent an object without or without pp can reasonably be called a picture. Whether it is the Hubble or my fujifilm makes no difference. they both collect photons, organize them and then recreate them. When my Sony shows me a Raw file on my LCD it is showing me a picture.

Brian,
The first part of this thread was mostly about manual or half-automat. Manfred and I tried to explain to you there is no difference when you follow the lightmeter. I'm still not sure you do understand that.

Now the second part will be the RAW. The RAW-file is a representation of the sensor. The analogue value of every sensel is digitized in a special way, 1 color channel per sensel. Now I hope Ted is keeping quite with his Sigma, having another type sensor.
A digital picture exists out off 3 colors per pixel. It's the way our eyes work, the monitor works, printer with some corrections works etc.

Anybody who compares a RAW with a JPG doesn't know where he talks about.
A RAW-file is not a picture as we want to see. The picture has to be converted out off the RAW-file.

So I would suggest read again your first post, think about what you wrote and ask yourself if and what you learned.

And if you think you can, post a RAW-picture.

George

[JBW]

Brian,
The first part of this thread was mostly about manual or half-automat. Manfred and I tried to explain to you there is no difference when you follow the lightmeter. I'm still not sure you do understand that.

Now the second part will be the RAW. The RAW-file is a representation of the sensor. The analogue value of every sensel is digitized in a special way, 1 color channel per sensel. Now I hope Ted is keeping quite with his Sigma, having another type sensor.
A digital picture exists out off 3 colors per pixel. It's the way our eyes work, the monitor works, printer with some corrections works etc.

Anybody who compares a RAW with a JPG doesn't know where he talks about.
A RAW-file is not a picture as we want to see. The picture has to be converted out off the RAW-file.

So I would suggest read again your first post, think about what you wrote and ask yourself if and what you learned.

And if you think you can, post a RAW-picture.

George

George you should accept your own challenge. Post a JPEG PICTURE without using technology. You can't do it. A JPEG is a collection of photons. So is a RAW file. They both need technology for us to see them as a picture. If a JPEG is a picture so is a RAW. They aren't the same any more than a pencil sketch is the same as an oil painting but if one is a picture so is the other.

[Black Pearl]

George you should accept your own challenge. Post a JPEG PICTURE without using technology. You can't do it. A JPEG is a collection of photons. So is a RAW file. They both need technology for us to see them as a picture. If a JPEG is a picture so is a RAW. They aren't the same any more than a pencil sketch is the same as an oil painting but if one is a picture so is the other.

True, you can't view a file regardless of what it is without technology - but - you can view a JPEG on any compatible device as it is in a finalised format with set in place and organised data. This isn't the case for a raw file as it is simply that, raw data from the sensor without any cohesive form. Try opening a raw file with a basic picture viewer and it won't because it can't interpretative the information, hell you can't even open raw files from recent camera with older versions of popular software like Photoshop as they won't have been updated with the algorithms needed.

Think of it this way - a raw file is like a ball of wool and a sheet of knitting patterns for a scarf. To be able to see the scarf you need to read the instructions and knit the wool together. You can't see the scarf straight away as it hasn't been made yet. This is what your raw software does, it takes the wool (light values from each pixel) reads the instructions (bayer pattern interpolation, colour profiles and all the other gubbins) then uses further instructions to knit the final pattern - the scarf (image) you can view.

A jpeg is the picture of the scarf on the front of the instructions. It is one persons interpretation of how the wool should be knitted together. You can maul it about a bit but it is fundamentally a final product.

Given a raw file (ball of wool) and the instructions and your raw software you can follow them expressly or you can add your own flourishes. Make it a bit longer and not as wide, add another bit of wool to change the colour, knit it tighter, a little more open you can do as you wish as you are the knitter.

[Shadowman]

And still didn't learn that a RAW-file is not a picture?

George

The technology was new to me as I'd just transitioned from film, so at the learning was just beginning.

[JBW]

True, you can't view a file regardless of what it is without technology - but - you can view a JPEG on any compatible device as it is in a finalised format with set in place and organised data. This isn't the case for a raw file as it is simply that, raw data from the sensor without any cohesive form. Try opening a raw file with a basic picture viewer and it won't because it can't interpretative the information, hell you can't even open raw files from recent camera with older versions of popular software like Photoshop as they won't have been updated with the algorithms needed.

Okay why not try to think of it this way?

Digital cameras are computers. This means that all they do is arrange 1's and 0's in particular ways. The fact that you can read JPEG on more devices than you can read RAW on simply means that more devices are built to read JPEG.

In either form you get nothing without something that will read the information. The following shot is a screen capture of a RAW file I was processing in Sony Express. the screen shot is 1's and 0's, so is the RAW file I was working on. This is exactly what it would have been if I had been working on a JPEG instead.

[george013]

Okay why not try to think of it this way?

Digital cameras are computers. This means that all they do is arrange 1's and 0's in particular ways. The fact that you can read JPEG on more devices than you can read RAW on simply means that more devices are built to read JPEG.

In either form you get nothing without something that will read the information. The following shot is a screen capture of a RAW file I was processing in Sony Express. the screen shot is 1's and 0's, so is the RAW file I was working on. This is exactly what it would have been if I had been working on a JPEG instead.

Looking for an example how a RAW-file would look transformed, not converted, to a raster image I found this article. I don't know the website. It's in english and not too long. http://photo.net/learn/raw/
Pay attention to the graphs. There are 2 blocks: 1) Bayern interpolation and 2)WB etc. This is where a RGB raster image is created. That's the image you can see on your screen.
Your screenshot above is a RAW-file that has gone through the same blocks as in the camera, only in another converter. One can say that any converter is working different, other priorities etc. The only way to see a RAW-flle is through a converter giving different images. That's the knitting Black Pearl mentioned so well.

That raster image will have 3 bytes per pixel minimal. When writing it on card it will take 72 MB for a 4000x6000 sensor. Just the image. This is where the JPG comes. It's nothing more than a compression method for such raster images. If you don't want to compress but still want a raster image from the in-camera converter, you could choice for TIFF. I think they will be more than 72 MB.

As you can see both JPG and TIFF have passed the conversion, the individual pixel values are fixed. The JPG has to be decompressed only. Probably the TIFF too.

Do you understand now why you can't simple show a RAW-file? It has to be converted/knitted to a raster format.

George

[JBW]

Looking for an example how a RAW-file would look transformed, not converted, to a raster image I found this article. I don't know the website. It's in english and not too long. http://photo.net/learn/raw/
Pay attention to the graphs. There are 2 blocks: 1) Bayern interpolation and 2)WB etc. This is where a RGB raster image is created. That's the image you can see on your screen.
Your screenshot above is a RAW-file that has gone through the same blocks as in the camera, only in another converter. One can say that any converter is working different, other priorities etc. The only way to see a RAW-flle is through a converter giving different images. That's the knitting Black Pearl mentioned so well.

That raster image will have 3 bytes per pixel minimal. When writing it on card it will take 72 MB for a 4000x6000 sensor. Just the image. This is where the JPG comes. It's nothing more than a compression method for such raster images. If you don't want to compress but still want a raster image from the in-camera converter, you could choice for TIFF. I think they will be more than 72 MB.

As you can see both JPG and TIFF have passed the conversion, the individual pixel values are fixed. The JPG has to be decompressed only. Probably the TIFF too.

Do you understand now why you can't simple show a RAW-file? It has to be converted/knitted to a raster format.

George

Yes George i understand that George. I also understand that you cannot simply upload any system of storing the photons our cameras catch. They all require a method of getting from the camera to here. And by7 the time they get here they are simply 0's and 1's. Go ahead try to directly post a JPEG from your sensor to here. By the time it gets here it has the name JPEg but it has been converted to 0's and 1's., And that's my final word on this topic.

[xpatUSA]

Here is a "RAW-file" straight from my camera's sensor outputs to a PNG, no conversion, no color space, no editing, just down-sized for posting:



Is it a picture or not, George?

You may explain that to me. Brian has a Nikon with a [Bayer pattern CFA] based sensor with R,G, and B sensels. A picture, digital, has a RGB pixel. Pay attention to the comma's.

[/QUOTE]

I paid attention to the commas, George.

Your earlier question "And still didn't learn that a RAW-file is not a picture?" came over as a bit sarcastic, I thought, because it did not end with a Smiley. So I decided to welcome you to the world of Foveon sensors which have 3 analog tri-chromatic outputs which are connected directly to 3 ADCs. That means that the ADCs combined into the raw X3F file are in a picture format which can shown on a screen with no Bayer de-mosaicing required.

George, are you sure that Brian has a Nikon? Even if he did, it would have R, G1, G2 and B sensels - not R,G,B.

Furthermore, a Bayer RAW-file can be presented on screen without de-mosaicing - usually by averaging G1 and G2.

Here is a Nikon NEF raw file opened with RawDigger showing the raw-composite view and it's raw histogram:



Subject was shot in the dark but is still a picture of a timepiece, wouldn't you say?

Now I'm going to get told that the image had to be de-mosaiced to show on the screen so here's a composite export of that same data:



Still a picture of a timepiece.

And, if the comment changes to "it's not a good image", think Pointillism or Dali et al.

A picture is a picture is a picture.

[xpatUSA]

People here keep talking as if raw data can not be shown on a screen as a picture, in spite of the fact I've done it twice already - once for Foveon and once for Bayer. That is to say, I have already shown that a recognizable image can be rendered from raw data on-screen.

In the closed world of "shoot raw - develop in proprietary converter - edit as required", no - what is seen on screen is not the raw data and that is probably what people are driving at.

But one of our members made a false statement and that was what I was addressing, no more that. I am satisfied that I have proved that raw data can be shown as a picture without conversion of any kind other than scaling and (for Bayer) averaging the greens.

Indeed, the gentleman from Nederland himself has changed his false statement to:

"A RAW-file is not a picture as we want to see." (my emphasis).

Which implies that he is now in agreement

I still say a picture is a picture - and discussion of it's quality or desirability in this context is just classic forum obfuscation.

[george013]

People here keep talking as if raw data can not be shown on a screen as a picture, in spite of the fact I've done it twice already - once for Foveon and once for Bayer. That is to say, I have already shown that a recognizable image can be rendered from raw data on-screen.

In the closed world of "shoot raw - develop in proprietary converter - edit as required", no - what is seen on screen is not the raw data and that is probably what people are driving at.

But one of our members made a false statement and that was what I was addressing, no more that. I am satisfied that I have proved that raw data can be shown as a picture without conversion of any kind other than scaling and (for Bayer) averaging the greens.

Indeed, the gentleman from Nederland himself has changed his false statement to:

"A RAW-file is not a picture as we want to see." (my emphasis).

Which implies that he is now in agreement

I still say a picture is a picture - and discussion of it's quality or desirability in this context is just classic forum obfuscation.

Are you sure?
Your Rawdigger screensave shows R, G and B values per pixel. Very odd for a RAW-image.
From the manual, bold is mine.

5. Image view mode:
 RGB render: shows the RGB representation with the selected (see description of Preferences below) white balance. This mode is not available for cameras where the aspect ratio of a single pixel differs from 1 (for example, some Fuji cameras).
 Raw Composite: for an RGB(G)-Raw it is an RGB-image where the green channel is computed by averaging two green channels available in the raw file. For all raw file where the CFA is not RGB(G) (but rather CFA is of a different type, like CMYG, RGBE, etc.) a grayscale image is displayed (i.e. Show RGBG in grayscale setting /see below/ is forced on for such files).
 Raw channel: the selected channel is shown in the black-and-white mode.
 OvExp: switches overexposure indication On; the overexposed areas are highlighted in red.
 UnExp: switches underexposure indication On; the underexposed areas are highlighted in blue.

If you go to preferences, then you can set the view to something like the sensor.

George

[xpatUSA]

Are you sure?
Your Rawdigger screensave shows R, G and B values per pixel. Very odd for a RAW-image.
From the manual, bold is mine.

Why did you bold the 'RGB render' text when my posted screen capture shows clearly that the 'Raw Composite' view was selected?

Why did you bold "RGB-image where the green channel is computed by averaging two green channels available in the raw file." when I already said that that's how it's done in a previous post?

If you go to preferences, then you can set the view to something like the sensor.

Education on how to use RawDigger will not be well-received, George.

Why are you ignoring the Bayer export that I posted below the screen capture?

These are posted as rhetorical questions because I know they will not get answered in a straight-forward manner, if at all.

The statement "a RAW-file is not a picture" remains false - and no amount of wriggling will prove otherwise.

Your move

[george013]

Why did you bold the 'RGB render' text when my posted screen capture shows clearly that the 'Raw Composite' view was selected?

Try it again. It is a RGB image.

Raw Composite: for an RGB(G)-Raw it is an RGB-image where the green channel is computed by averaging two green channels available in the raw file. For all raw file where the CFA is not RGB(G) (but rather CFA is of a different type, like CMYG, RGBE, etc.) a grayscale image is displayed (i.e. Show RGBG in grayscale setting /see below/ is forced on for such files).

And again. It is a RGB image.

Why did you bold "RGB-image where the green channel is computed by averaging two green channels available in the raw file." when I already said that that's how it's done in a previous post?

This is an arrogance I seldom see.

Education on how to use RawDigger will not be well-received, George.

From the same manual:

Export Tiff: exports the data of the currently opened RAW-file as TIFF (see Data Export section below).

Why are you ignoring the Bayer export that I posted below the screen capture?

These are posted as rhetorical questions because I know they will not get answered in a straight-forward manner, if at all.

The statement "a RAW-file is not a picture" remains false - and no amount of wriggling will prove otherwise.

Your move

I'm still waiting for a RAW-file as an image. Either you convert it or transform it to a RGB raster image where only 1 colour per pixel is used. For photography useless.

I still can't see the practical use of the program.

Best wishes,

George

[pnodrog]

Actually none of the files (JPEG, TIFF, NEF, RAW etc etc) are images........

They are all various different arrays of data that require software to interpret the file, adjust the colour profile for the targeted output (monitor, printer etc) and store this new array in memory so the specific drivers for the output device can then send it on for display or printing. All the file types need interpreting but some require simpler software to interpret them.

I am not sure what you are all arguing about but more importantly why. You can discuss the advantages and disadvantages of the various file formats but none of them are directly view-able images. They all look boring with a hex viewer.

[Black Pearl]

Your move

I can just picture you pressing the "Post Reply" button, kicking your chair back which will be on wheels on a wooden floor so you can roll and spin with a flourish, then making a gun shape with your fingers and shouting 'Bang' while pointing them at the screen. After a swagger down the hall picking up your Stetson on the way you'd have gone out onto your stoop, stood with your thumbs in your belt, pretend drew your gun again and imagined you shot a row of bottles off your fence. After a bit more strutting you'd have sat, put your feet on the railings and yelled 'Mary-Sue, bring me a beer and make sure it's cold this time!"

Or perhaps not

[pnodrog]

I can just picture you pressing the "Post Reply" button, kicking your chair back which will be on wheels on a wooden floor so you can roll and spin with a flourish, then making a gun shape with your fingers and shouting 'Bang' while pointing them at the screen. After a swagger down the hall picking up your Stetson on the way you'd have gone out onto your stoop, stood with your thumbs in your belt, pretend drew your gun again and imagined you shot a row of bottles off your fence. After a bit more strutting you'd have sat, put your feet on the railings and yelled 'Mary-Sue, bring me a beer and make sure it's cold this time!"

Or perhaps not

What worries me is I can visualise it all so clearly.... "Robin Pearl" famous western writer ranks along side Zane Grey, Max Brand and J T Edson.......

[tao2]

Sheeesh Marshal,
Well ah'll be hornswoggled...

[xpatUSA]

Thanks Gents,

I supposed I asked for it :|

[Mike Buckley]

'Mary-Sue, bring me a beer and make sure it's cold this time!"

"Get yer own dang beer 'cuz I'm afixin' to divorce ya. I got a picture of you and that sweet young thing of yers in the raw. Hell's bells, the JPEG came out just as good."

[pnodrog]

Thanks Gents,

I supposed I asked for it :|

No, Ted you don't deserve it. Robin's imagination is just a bit of a worry. I had just assumed you were in front of a chess board and had restarted the timer. Informing your opponent is a very sporting gesture...

P.S. I for one appreciate the points you make.