2 simple RAW questions

Hello all,

I have two simple RAW related questions, but nobody has been able to give me a clear and precise answer so far.

I am sure you will

So here we go:

1) when I shoot RAW only with the 350D, what is the exact nature of the embedded JPEG ? Is it exactly the same as Large/Fine ?

When I shoot RAW, I shoot RAW + JPEG, but recently I discovered that Irfanview is able to display instantly the RAW files, and unlike what I often read, the image was a full 3456x2304 one... and was identical to the JPEG one stored separately, showing that Irfanview was not calculating the output (XnView does that, but then it is veeery slow, and the output is very different from the JPEG output by the 350D).

Does it mean the RAW file on the 350D always embed the JPEG Large/Fine ?

2) I have some problems with CA (red/cyan) and my 10-22mm. I tried to reduce it with different tools (CAFree or panotools), and it works well, but you have to tweak the settings.

With RAW conversion (with RSE for instance) the CA problems seem to be corrected (not 100%, but most of it). My question is: how do they proceed ? Is it an "average correction" which is quite ok for most lenses ?

I would like to be able to apply such a correction on my JPEG images...

My question is really: how does it work ? How is the CA removed, does it take into account the body + lens combination or not ? Is the removal more efficient because the RAW file has more data, and the R G B channels are available separately ?

Thanks for any answer...

--
Cedric Simon

Cedric,

I just opened a .CR2 from my XT in Irfanview, its 1536 x 1024 at 24bit, hardly full size. Its has always been my understanding that the embedded JPEG is 300KB in size and it reflects the camera settings in effect when shot, ie: WB, saturation, sharpening, etc. The RAW file would also have these settings in the header and they COULD be used if your RAW converter is set to default settings.

I'm sure you're aware, Irfanview is NOT a RAW converter, therefore it can only display the embedded JPEG, never demosic the RAW file.

Cedric Simon said:

Cedric Simon wrote:
1) when I shoot RAW only with the 350D, what is the exact nature of
the embedded JPEG ? Is it exactly the same as Large/Fine ?

When I shoot RAW, I shoot RAW + JPEG, but recently I discovered
that Irfanview is able to display instantly the RAW files, and
unlike what I often read, the image was a full 3456x2304 one... and
was identical to the JPEG one stored separately, showing that
Irfanview was not calculating the output (XnView does that, but
then it is veeery slow, and the output is very different from the
JPEG output by the 350D).

Does it mean the RAW file on the 350D always embed the JPEG
Large/Fine ?

Click to expand...

Perhaps you pointed Irfanview to a RAW + JPEG file and it by default looks for an attached JPEG, not the embedded JPEG. A simple test will provide an answer.

Cedric Simon said:

2) I have some problems with CA (red/cyan) and my 10-22mm. I tried
to reduce it with different tools (CAFree or panotools), and it
works well, but you have to tweak the settings.

With RAW conversion (with RSE for instance) the CA problems seem to
be corrected (not 100%, but most of it). My question is: how do
they proceed ? Is it an "average correction" which is quite ok for
most lenses ?

I would like to be able to apply such a correction on my JPEG
images...

My question is really: how does it work ? How is the CA removed,
does it take into account the body + lens combination or not ? Is
the removal more efficient because the RAW file has more data, and
the R G B channels are available separately ?

Click to expand...

Not a clue!!!

Hermit

--
Lost in the Colorado Mountains!!!

1. The 350 allows menu selection of the JPG that accompanies the RAW. Using the RAW plus large option uses a lot more CF space but some people like having both straight from camera.

2. I have no idea how RawShooter works on CA but agree it does. I don't believe that the program knows what lens is used (just what focal length) so I assume it works by comparing the sizes of the primary color separations and adjusting them to line up better. I hope someone has the technical answer to this one but I suspect RawShooter would consider this a proprietary secret.

PTLens is freeware and helps JPG's with CA issues. I suspect there are other programs that do at least as well but that is the one I have tried.
--
Doug Smith
http://www.pbase.com/dougsmit

Hello,

21st Hermit said:

I just opened a .CR2 from my XT in Irfanview, its 1536 x 1024 at
24bit, hardly full size. Its has always been my understanding that
the embedded JPEG is 300KB

Click to expand...

this is what I thought as well...

21st Hermit said:

I'm sure you're aware, Irfanview is NOT a RAW converter, therefore
it can only display the embedded JPEG, never demosic the RAW file.

Click to expand...

yes I know... this is why I am wondering how it can display a nice full size JPEG when I only open a .CR2 file...

21st Hermit said:

Perhaps you pointed Irfanview to a RAW + JPEG file and it by
default looks for an attached JPEG, not the embedded JPEG. A simple
test will provide an answer.

Click to expand...

yes I guess this is the answer... I'll try this simple test, I am sure Irfanview cheats and looks for the JPEG file !

Hello again,

I am far from my 350D at the moment, so I downloaded a single CR2 file from internet from this address:

http://www.jirvana.com/raw_large/350d/

and irfanview opened it... and it is a full 3474x2314 file...

Cedric Simon said:

Cedric Simon said:

I just opened a .CR2 from my XT in Irfanview, its 1536 x 1024 at
24bit, hardly full size. Its has always been my understanding that
the embedded JPEG is 300KB

Click to expand...

this is what I thought as well...

Cedric Simon said:

I'm sure you're aware, Irfanview is NOT a RAW converter, therefore
it can only display the embedded JPEG, never demosic the RAW file.

Click to expand...

yes I know... this is why I am wondering how it can display a nice
full size JPEG when I only open a .CR2 file...

Cedric Simon said:

Perhaps you pointed Irfanview to a RAW + JPEG file and it by
default looks for an attached JPEG, not the embedded JPEG. A simple
test will provide an answer.

Click to expand...

yes I guess this is the answer... I'll try this simple test, I am
sure Irfanview cheats and looks for the JPEG file !

Click to expand...

ok I 'll have to test tonight with my RAW + JPEG pairs.

But if I take a single CR2 file, and ask irfanview not to use the embedded JPEG (which is small, you're perfectly right), then it is sloooww but it displays the image, full size. So somehow it knows how to devellop RAW !

Cedric Simon said:

http://www.jirvana.com/raw_large/350d/

and irfanview opened it... and it is a full 3474x2314 file...

Cedric Simon said:

Cedric Simon said:

I just opened a .CR2 from my XT in Irfanview, its 1536 x 1024 at
24bit, hardly full size. Its has always been my understanding that
the embedded JPEG is 300KB

Click to expand...

this is what I thought as well...

Cedric Simon said:

I'm sure you're aware, Irfanview is NOT a RAW converter, therefore
it can only display the embedded JPEG, never demosic the RAW file.

Click to expand...

yes I know... this is why I am wondering how it can display a nice
full size JPEG when I only open a .CR2 file...

Cedric Simon said:

Perhaps you pointed Irfanview to a RAW + JPEG file and it by
default looks for an attached JPEG, not the embedded JPEG. A simple
test will provide an answer.

Click to expand...

yes I guess this is the answer... I'll try this simple test, I am
sure Irfanview cheats and looks for the JPEG file !

Click to expand...

Click to expand...

I don't know the answer, but its possible than the embedded JPEG is related to the size of the attached JPEG. There is logic in doing this, less CPU time creating 2 different JPEG's. Clearly, my plain .CR2 had a 1536 x 1024 JPEG, no reason your XT would not be the same.

So the simple test I suggested is now more complex. That's Life!!!

Hermit

--
Lost in the Colorado Mountains!!!

just read this: (irfanview plugins page)

CRW - (version 3.98): allows IrfanView to read Canon CRW/CR2 files (high resolution image version)
Note: this PlugIn requires additional Canon DLLs.

As I installed the Canon Software at home, this explains why Irfanview manages to decode CR2 so fast !

But here, on a non-Canon aware PC, I tell you Irfanview 3.98 that I just downloaded knows how to transform the RAW file !

This is possible...
Then this would mean that RAW + JPEG generates a larger RAW...
Many tests to do tonight

Anyway, I know know that Irfanview standalone can read CR2 files (but slow) and Irfanview + Canon dll's (downloadable from irfanview site) can really read CR2 very fast !

21st Hermit said:

I don't know the answer, but its possible than the embedded JPEG is
related to the size of the attached JPEG. There is logic in doing
this, less CPU time creating 2 different JPEG's. Clearly, my plain
.CR2 had a 1536 x 1024 JPEG, no reason your XT would not be the
same.

So the simple test I suggested is now more complex. That's Life!!!

Hermit

--
Lost in the Colorado Mountains!!!

Click to expand...

ok, I tried to download the Canon DLL's, and here is my conclusion:

Irfanview needs the same time to decode the CR2 file with or without the Canon DLLs (9 seconds on a 3Ghz P4 with 1Gig RAM), but

using Canon DLLs, the result is identical (as far as I can tell) to the embedded JPEG, except for the larger size, meaning that it seems to apply the exact same settings.

Using the "internal" RAW decoded, Irfanview generates an image which is softer and less bright (I guess no sharpen / contrast / saturation has been applied at all).

I'll check at home tonight to try to understand how my home PC can decode CR2 so fast, maybe it was just using the embedded JPEG and my memory is wrong.

But the conclusion is that Irfanview does indeed decode RAW files natively !

Cedric Simon said:

just read this: (irfanview plugins page)

CRW - (version 3.98): allows IrfanView to read Canon CRW/CR2 files
(high resolution image version)
Note: this PlugIn requires additional Canon DLLs.

As I installed the Canon Software at home, this explains why
Irfanview manages to decode CR2 so fast !

But here, on a non-Canon aware PC, I tell you Irfanview 3.98 that I
just downloaded knows how to transform the RAW file !

Click to expand...

I can't keep up. All my truths are now lies. That's life too!!!

I'm looking forward to your tests.

Hermit

Cedric Simon said:

Cedric Simon wrote:
But here, on a non-Canon aware PC, I tell you Irfanview 3.98 that I
just downloaded knows how to transform the RAW file !

Click to expand...

--
Lost in the Colorado Mountains!!!

Cedric Simon said:

1) when I shoot RAW only with the 350D, what is the exact nature of
the embedded JPEG ? Is it exactly the same as Large/Fine ?

Click to expand...

No. It is about 1.5 megapixels.

When you shoot Raw+JPEG on the XT/350D, you're limited to Large/Fine JPEG. As a result, the embedded JPEG is Large/Fine. But when you shoot Raw-only, the embedded JPEG is 1.5 mpix.

As a result, the .CR2 files are considerably larger when you're shooting Raw+JPEG than when you're shooting Raw-only.

Cedric Simon said:

2) I have some problems with CA (red/cyan) and my 10-22mm. I tried
to reduce it with different tools (CAFree or panotools), and it
works well, but you have to tweak the settings.
[snip]
I would like to be able to apply such a correction on my JPEG
images...

Click to expand...

PTLens (from panotools) is what I use.

If you're willing to part with some money, DxO Optics Pro will fix up the CA automatically.

Hi there,

Doug Pardee said:

As a result, the .CR2 files are considerably larger when you're
shooting Raw+JPEG than when you're shooting Raw-only.

Click to expand...

ok, ok !!

So if I understand well, either you have a big RAW + a big JPEG, or a smaller RAW, and no JPEG.

I had always been wondering why my RAW files were so big !
It was because I kept the RAW + JPEG option.

I did not want to get rid of the JPEG because when you are away from your home and have access to nothing but a simple public machine to view/post your images, JPEG are convenient...

but now that I know that Irfanview can indeed "develop" raw files natively...

Doug Pardee said:

Doug Pardee said:

2) I have some problems with CA (red/cyan) and my 10-22mm. I tried
to reduce it with different tools (CAFree or panotools), and it
works well, but you have to tweak the settings.
[snip]
I would like to be able to apply such a correction on my JPEG
images...

Click to expand...

PTLens (from panotools) is what I use.

If you're willing to part with some money, DxO Optics Pro will fix
up the CA automatically.

Click to expand...

Hello,
it is not only possible, but it is the exact behavior of the beast.

I shot the same scene, RAW and RAW + JPEG:

RAW only: CR2 =7159Ko
RAW + JPEG: CR2 = 9343Ko and JPG =2522Ko

ouch !

21st Hermit said:

I don't know the answer, but its possible than the embedded JPEG is
related to the size of the attached JPEG. There is logic in doing
this, less CPU time creating 2 different JPEG's. Clearly, my plain
.CR2 had a 1536 x 1024 JPEG, no reason your XT would not be the
same.

So the simple test I suggested is now more complex. That's Life!!!

Hermit

--
Lost in the Colorado Mountains!!!

Click to expand...

Irfanview will "develop" natively, as I found out myself a few weeks ago, but it does not seem to provide with some modifying options suc as white balance.

It think it should be used only to view RAW files and not convert them (or at least, I would keep my RAW for further modifications).

I like Irfanview, it is actually this tool that decided me to eliminate to shoot jpeg at all.

--
Regards,

Benjilafouine

I agree there is logic in saving only 1 jpeg size( and embedding that file) and thus saving processing power in camera. The strange thing is that, to my knowledge, the 20D wich runs the same DIGIC II processor does not do this.
My idea has been that this is , in the 350D, a carry over from the 300D.

Try asking this question to Canon Support

I was told that the difference in raw file size when you shoot raw only is differnt compression on raw file.

How I know why I don't shoot RAW + JPEG. By your example: 7MB vs 13MB, almost double.

Ouch Indeed !!!!

Cedric Simon said:

Cedric Simon wrote:
Hello,
it is not only possible, but it is the exact behavior of the beast.

I shot the same scene, RAW and RAW + JPEG:

RAW only: CR2 =7159Ko
RAW + JPEG: CR2 = 9343Ko and JPG =2522Ko

ouch !

21st Hermit said:

I don't know the answer, but its possible than the embedded JPEG is
related to the size of the attached JPEG. There is logic in doing
this, less CPU time creating 2 different JPEG's. Clearly, my plain
.CR2 had a 1536 x 1024 JPEG, no reason your XT would not be the
same.

So the simple test I suggested is now more complex. That's Life!!!

Hermit

--
Lost in the Colorado Mountains!!!

Click to expand...

Click to expand...

--
Lost in the Colorado Mountains!!!

Clearly the XT is a defeatured 20D, some for engineering reasons, some for marketing reasons. However, because the XT is some 6-months newer than the 20D, it writes to CF almost 20% faster than the 20D . . . go figure.

Enicar said:

Enicar wrote:
I agree there is logic in saving only 1 jpeg size( and embedding
that file) and thus saving processing power in camera. The strange
thing is that, to my knowledge, the 20D wich runs the same DIGIC II
processor does not do this.
My idea has been that this is , in the 350D, a carry over from the
300D.

Click to expand...

Enicar said:

Try asking this question to Canon Support
I was told that the difference in raw file size when you shoot raw
only is differnt compression on raw file.

Click to expand...

That is a sad comment on the skills of tech support.

Hermit

--
Lost in the Colorado Mountains!!!

Doug Pardee said:

Doug Pardee said:

2) I have some problems with CA (red/cyan) and my 10-22mm. I tried
to reduce it with different tools (CAFree or panotools), and it
works well, but you have to tweak the settings.
[snip]
I would like to be able to apply such a correction on my JPEG
images...

Click to expand...

PTLens (from panotools) is what I use.

If you're willing to part with some money, DxO Optics Pro will fix
up the CA automatically.

Click to expand...

PTLens is like the Adobe Camera Raw CA remover feature isn't it?
It requires you to move sliders to tweak the fix...

Is there any PS plugin which will perform auto CA fix?

I'm not particularly keen to open PaintShop Pro X to complete a workflow...

PC absolutely chugs when you have RSE and PS CS2 running...then u want to open PSP X and or Neat Image and suddenly your new PC ain't so fast no more...

Hi "benjilafouine",

you have a cute nickname (I am French)

I agree 100% with your comment.

I can really say that now that I know that Irfanview can view RAW files, and "develop" them if necessary, I think I'll try to shoot RAW without JPEG exclusively.

And anyway, I always have a USB key on me, it is easy to copy Irfanview and RSE2006 on it as they are relatively small packages.

benjilafouine said:

Irfanview will "develop" natively, as I found out myself a few
weeks ago, but it does not seem to provide with some modifying
options suc as white balance.

It think it should be used only to view RAW files and not convert
them (or at least, I would keep my RAW for further modifications).

I like Irfanview, it is actually this tool that decided me to
eliminate to shoot jpeg at all.

--
Regards,

Benjilafouine

Click to expand...