Saving Pictures in Tiff CMYK or RGB??

On 23-Dec-2003, "WStoreyII" wrote:

I have recently learned that jpgs corrupt files. So i opened psp6 and went
to convert all the files that i have in to Tiffs however it had an option for RGB format or CMYK format. My questions is which one do i use, my printer (Epson Stylus Cx5400)uses cmyk color cartridges so i was thinking that is what i should use and that i could convert them to rgb if i need to
use them for the web or anything.

Please tell me if this is the right assumption and if not what to do.

First, since they’re already jpeg, leave them as jpeg. The ‘corruption’ has already happened. When you edit them you can save the edited copy as a tiff.

Second, save them as RGB. The jpegs are RGB and you will loose some information in the conversion. Your printer will do the RGB->CMYK conversion when you print.

—
Tom Thackrey
www.creative-light.com
tom (at) creative (dash) light (dot) com
do NOT send email to (it’s reserved for spammers)

WStoreyII wrote:

Hello,

I have recently learned that jpgs corrupt files. So i opened psp6 and went to convert all the files that i have in to Tiffs however it had an option for RGB format or CMYK format. My questions is which one do i use, my printer (Epson Stylus Cx5400)uses cmyk color cartridges so i was thinking that is what i should use and that i could convert them to rgb if i need to use them for the web or anything.

Please tell me if this is the right assumption and if not what to do.

Save yourself some work. Stick with RGB, since your printer driver takes RGB input anyway.

And save yourself some work and stick with your jpgs for that matter. Jpegs will indeed lose quality, but only each time you re-save in jpeg format.

Treat your original jpeg from the camera as if it were a negative, save your edited image to another file, and avoid compressing the image more than one additional time. If you plan to edit the same image again, save in an umcompressed format such as tiff or psd.

Above all, try these things out for yourself and see if you can see the difference – trust your eyes over anything you read here, including anything I say 🙂
—

Mike Russell
www.curvemeister.com
www.geigy.2y.net

"Above all, try these things out for yourself and see if you can see the difference – trust your eyes over anything you read here, including anything I say :-)"

I’ve noticed that there are a lot of very knowledgeable people in these groups, along with a lot of people who think that they are knowledgeable – problem is it’s hard sometimes to tell the one from the other.

Martin

Mike Russell wrote:

WStoreyII wrote:

Hello,

I have recently learned that jpgs corrupt files. So i opened psp6 and went to convert all the files that i have in to Tiffs however it had an option for RGB format or CMYK format. My questions is which one do i use, my printer (Epson Stylus Cx5400)uses cmyk color cartridges so i was thinking that is what i should use and that i could convert them to rgb if i need to use them for the web or anything.

Please tell me if this is the right assumption and if not what to do.

Save yourself some work. Stick with RGB, since your printer driver takes RGB input anyway.

And save yourself some work and stick with your jpgs for that matter. Jpegs will indeed lose quality, but only each time you re-save in jpeg format.
Treat your original jpeg from the camera as if it were a negative, save your edited image to another file, and avoid compressing the image more than one additional time. If you plan to edit the same image again, save in an umcompressed format such as tiff or psd.

Above all, try these things out for yourself and see if you can see the difference – trust your eyes over anything you read here, including anything I say 🙂
—

Mike Russell
www.curvemeister.com
www.geigy.2y.net

Everything you are trying to do is incorrect.

1. Where did you learn that jpg corrupts files? Nonsense.

2. Your camera is sRGB, your video display is sRGB. All printers are CMYK. There is no sense in saving a picture in CMYK. XP (or any photo software) sends your sRGB file to your printer, it is translated automatically to what your printer can understand.

If you converted to .tif you will see that these files will be about 10 times the size of .jpg.

The only time you want to save in .tif is when you want to edit the file many times and "save as" many times.

We used .tif in the old days because resolution was poor and "save as" jpg many times would degrade the image. These days are gone with cameras of 2 MP and above.

If you want to convert the .tif files back to jpg you can use this free batch converter:
http://www.irfanview.com/

Here is a way to do your own experiment.

This used to be correct, in the days of poor resolution digital cameras and scanners. Things have changed dramatically and unless you want to print very large (by large I mean more than 12 x 18) from a pro shop there is absolutely no advantage to save tif files over jpg.

The first point is, every time you "Save as" a jpg there is a little loss and artifacts introduced, so if you edit a picture and you Save as many time, there is some degradation with each Save as, but not with Save if you use Save to save your changes as you are editing(even if you don’t do anything to the picture and you Save as just to change the name of the file, it is the Save as that is the problem). So if you plan to edit the file many times, keep it in tif until done and then save it as jpg. Since you can always saved it back as tif for further editing, no problem. The second point is, can you see the difference? Only you can tell, no amount of info will convince you. So you do the experiment yourself. It has been done many times. Here is how to do it.
Take one of your jpg file, right click on it and click on Copy. Hold the Ctrl key down and press the letter V. This will make a new file in your folder "Copy of filename.jpg (note there is no degradation when you do this, since you don’t open the file and Save as, you only copied it). Now.
1. Open this file in your photo editor and Save as. Give it the name Copy of
filename 1.jpg
2. Open Copy of filename 1.jpg, Save as and change 1 to 2.
3. Continue doing this until you Save as this file 15 times.
The first point is, every time you "Save as" a jpg there is a little loss and artifacts introduced, so if you edit a picture and you Save as many time, there is some degradation with each Save as, but not with Save if you use Save to save your changes as you are editing(even if you don’t do anything to the picture and you Save as just to change the name of the file, it is the Save as that is the problem). So if you plan to edit the file many times, keep it in tif until done and then save it as jpg. Since you can always saved it back as tif for further editing, no problem. The second point is, can you see the difference? Only you can tell, no amount of info will convince you. So you do the experiment yourself. It has been done many times. Here is how to do it.
Take one of your jpg file, right click on it and click on Copy. Hold the Ctrl key down and press the letter V. This will make a new file in your folder "Copy of filename.jpg (note there is no degradation when you do this, since you don’t open the file and Save as, you only copied it). Now.
1. Open this file in your photo editor and Save as. Give it the name Copy of
filename 1.jpg
2. Open Copy of filename 1.jpg, Save as and change 1 to 2.
3. Continue doing this until you Save as this file 15 times.
Then you can start opening them and look at them on your screen, when do you begin to see degradation? Can’t see it yet, keep going to 25. But the real test is not seeing on your screen, you screen magnifies everything and we don’t trust you since you know the number you are looking at.
Now, print number 1, 3, 9, 15 and 25. Print as large as your printer can print.
Don’t look at the print too closely, just place a little number in pencil on the back of them. Then, give them to somebody and ask them to place them on a table in a different order. Can you pick No.1? If you do, try again the next day. Did you get it again? If you can pick No 1 consistently, then it does make a difference. If not, no more to argue about.
Then you can ask your tif friends to pick the print they think is the best. You may be surprised!
Give us the results a few weeks from now.

begin to see degradation? Can’t see it yet, keep going to 25. But the real test is not seeing on your screen, you screen magnifies everything and we don’t trust you since you know the number you are looking at.
Now, print number 1, 3, 9, 15 and 25. Print as large as your printer can print.
Don’t look at the print too closely, just place a little number in pencil on the back of them. Then, give them to somebody and ask them to place them on a table in a different order. Can you pick No.1? If you do, try again the next day. Did you get it again? If you can pick No 1 consistently, then it does make a difference. If not, no more to argue about.
Then you can ask your tif friends to pick the print they think is the best. You may be surprised!
Give us the results a few weeks from now.

"WStoreyII" wrote in message

Hello,

I have recently learned that jpgs corrupt files. So i opened psp6 and

went

to convert all the files that i have in to Tiffs however it had an option for RGB format or CMYK format. My questions is which one do i use, my printer (Epson Stylus Cx5400)uses cmyk color cartridges so i was thinking that is what i should use and that i could convert them to rgb if i need

to

use them for the web or anything.

Please tell me if this is the right assumption and if not what to do.
Thanks & Happy Holidays

WStoreyII
Emailto:

On Tue, 23 Dec 2003 14:51:02 -0500, "Yves Alarie" <rd50> wrote:

Everything you are trying to do is incorrect.

1. Where did you learn that jpg corrupts files? Nonsense.

Ah… considering the expertise of the original poster, I think you should have simply assumed that by "corrupt" he was taking about how the jpeg compression scheme causes a lose in quality. I don’t think he was actually talking about a corrupt file in the same sense as a corrupt computer file.

2. Your camera is sRGB, your video display is sRGB. All printers are CMYK. There is no sense in saving a picture in CMYK. XP (or any photo software) sends your sRGB file to your printer, it is translated automatically to what your printer can understand.

There is a reason for the CMYK and by not mentioning it you do a disservice to the poster and the group. The CMYK format is a requirement when preparing the images for printing on a printing press (PS is after all a professional level tool).

We used .tif in the old days because resolution was poor and "save as" jpg many times would degrade the image. These days are gone with cameras of 2 MP and above.

Drivel… "in the old days" "and "these days are gone" (what ever that means) PLEASE! Saving a jpg many times still degrades the image, doesn’t matter how many megapixels you start with.

— JC

On Tue, 23 Dec 2003 12:48:24 -0600, Rowley wrote:

I’ve noticed that there are a lot of very knowledgeable people in these groups, along with a lot of people who think that they are knowledgeable – problem is it’s hard sometimes to tell the one from the other.

Hang around for a few years and you will be able to easily spot the pros from the posers.

— JC

"Yves Alarie" <rd50> writes:

Everything you are trying to do is incorrect.

1. Where did you learn that jpg corrupts files? Nonsense.

Not "nonsense". JPEG is lossy compression: you don’t get back the same bits you put into it. Once that happens, of course you can’t get back to the original bits. But that may not be a problem, as JPEG is designed to throw away information that isn’t visible, anyway. Except, of course, that the degree of compression (and hence the degree of loss) is adjustable; it’s certainly possible to make visible changes to an image by saving it as JPEG with too much compression.

That said, it seems that every time a JPEG image is loaded, modified, and saved again can lose more data. Probably not much, but something to think about if you are processing images through many steps. In that situation, lossless image storage may be worthwhile.

2. Your camera is sRGB, your video display is sRGB.

Well, they are RGB. Quite possibly not sRGB, which is a specific standard.

All printers are CMYK.

Except those that are CMY, of course :).

There is no sense in saving a picture in CMYK. XP (or any photo software) sends your sRGB file to your printer, it is translated automatically to what your printer can understand.

If you converted to .tif you will see that these files will be about 10 times the size of .jpg.

Depending on compression level in the JPEG, of course. And the content of each image. I just saved an image in TIFF with LZW compression; it was 518728 bytes. The same image in JPEG (quality 10 from Photoshop 6) was 232158 bytes. I think you’ve overstated your case. Almost as badly as "JPEG corrupts files".

The only time you want to save in .tif is when you want to edit the file many times and "save as" many times.

Exactly.

We used .tif in the old days because resolution was poor and "save as" jpg many times would degrade the image. These days are gone with cameras of 2 MP and above.

I’m not sure why I should be glad to lose detail in, say, a 3MP image. If I pay for a 3MP camera, it would be nice to preserve all that detail.

If you want to convert the .tif files back to jpg you can use this free batch converter:
http://www.irfanview.com/

Here is a way to do your own experiment.

This used to be correct, in the days of poor resolution digital cameras and scanners. Things have changed dramatically and unless you want to print very large (by large I mean more than 12 x 18) from a pro shop there is absolutely no advantage to save tif files over jpg.

Except you said that editing/saving many times is a situation where you want lossless compression.

The first point is, every time you "Save as" a jpg there is a little loss and artifacts introduced, so if you edit a picture and you Save as many time, there is some degradation with each Save as, but not with Save if you use Save to save your changes as you are editing(even if you don’t do anything to the picture and you Save as just to change the name of the file, it is the Save as that is the problem).

Huh? How do you know this?

So if you plan to edit the file many
times, keep it in tif until done and then save it as jpg. Since you can always saved it back as tif for further editing, no problem.

Exactly.

The second point is, can you see the difference? Only you can tell, no amount of info will convince you. So you do the experiment yourself. It has been done many times. Here is how to do it.
Take one of your jpg file, right click on it and click on Copy. Hold the Ctrl key down and press the letter V. This will make a new file in your folder "Copy of filename.jpg (note there is no degradation when you do this, since you don’t open the file and Save as, you only copied it). Now.
1. Open this file in your photo editor and Save as. Give it the name Copy of
filename 1.jpg
2. Open Copy of filename 1.jpg, Save as and change 1 to 2.
3. Continue doing this until you Save as this file 15 times.

I’m not sure this will show the problem. Certainly closing, re-opening, and re-saving will.

<snip>

And yes, the experiment sounds like a valid one.

—
-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.

I have seen a lot of debat on this issue today since posting this,

since the general concensus seems to be that since the camera captured the picture in jpg that it is already damaged (a little) that i can at least save this on cd in this format and then if i choose to edit save it as a psd or a tiff.

Thanks for all the Help & Happy Holidays

"Stephen H. Westin" <westin*> wrote in message

"Yves Alarie" <rd50> writes:

Everything you are trying to do is incorrect.

1. Where did you learn that jpg corrupts files? Nonsense.

Not "nonsense". JPEG is lossy compression: you don’t get back the same bits you put into it. Once that happens, of course you can’t get back to the original bits. But that may not be a problem, as JPEG is designed to throw away information that isn’t visible, anyway. Except, of course, that the degree of compression (and hence the degree of loss) is adjustable; it’s certainly possible to make visible changes to an image by saving it as JPEG with too much compression.
That said, it seems that every time a JPEG image is loaded, modified, and saved again can lose more data. Probably not much, but something to think about if you are processing images through many steps. In that situation, lossless image storage may be worthwhile.

2. Your camera is sRGB, your video display is sRGB.

Well, they are RGB. Quite possibly not sRGB, which is a specific standard.

All printers are CMYK.

Except those that are CMY, of course :).

There is no sense in saving a picture in CMYK. XP (or any photo

software)

sends your sRGB file to your printer, it is translated automatically to

what

your printer can understand.

If you converted to .tif you will see that these files will be about 10 times the size of .jpg.

Depending on compression level in the JPEG, of course. And the content of each image. I just saved an image in TIFF with LZW compression; it was 518728 bytes. The same image in JPEG (quality 10 from Photoshop 6) was 232158 bytes. I think you’ve overstated your case. Almost as badly as "JPEG corrupts files".

The only time you want to save in .tif is when you want to edit the file many times and "save as" many times.

Exactly.

We used .tif in the old days because resolution was poor and "save as"

jpg

many times would degrade the image. These days are gone with cameras of

2 MP

and above.

I’m not sure why I should be glad to lose detail in, say, a 3MP image. If I pay for a 3MP camera, it would be nice to preserve all that detail.

If you want to convert the .tif files back to jpg you can use this free batch converter:
http://www.irfanview.com/

Here is a way to do your own experiment.

This used to be correct, in the days of poor resolution digital cameras

and

scanners. Things have changed dramatically and unless you want to print

very

large (by large I mean more than 12 x 18) from a pro shop there is absolutely no advantage to save tif files over jpg.

Except you said that editing/saving many times is a situation where you want lossless compression.

The first point is, every time you "Save as" a jpg there is a little

loss

and artifacts introduced, so if you edit a picture and you Save as many time, there is some degradation with each Save as, but not with Save if

you

use Save to save your changes as you are editing(even if you don’t do anything to the picture and you Save as just to change the name of the

file,

it is the Save as that is the problem).

Huh? How do you know this?

So if you plan to edit the file many
times, keep it in tif until done and then save it as jpg. Since you can always saved it back as tif for further editing, no problem.

Exactly.

The second point is, can you see the difference? Only you can tell, no amount of info will convince you. So you do the experiment yourself. It

has

been done many times. Here is how to do it.
Take one of your jpg file, right click on it and click on Copy. Hold the Ctrl key down and press the letter V. This will make a new file in your folder "Copy of filename.jpg (note there is no degradation when you do

this,

since you don’t open the file and Save as, you only copied it). Now.
1. Open this file in your photo editor and Save as. Give it the name

Copy of

filename 1.jpg
2. Open Copy of filename 1.jpg, Save as and change 1 to 2.
3. Continue doing this until you Save as this file 15 times.

I’m not sure this will show the problem. Certainly closing, re-opening, and re-saving will.

<snip>

And yes, the experiment sounds like a valid one.

—
-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.

Just do the experiment yourself.
You have a 3 MP camera. You have the option to save in .jpg or .tif. Take the same picture, one in jpg and one in tif
Then print. If you think you can tell the difference between one and the other, then use the one you prefer. No more arguments!
You asked a very good question. The jpg vs tif has been around a long time. With new camera Christmas gifts, I am sure we will get this question again. "WStoreyII" wrote in message

I have seen a lot of debat on this issue today since posting this,
since the general concensus seems to be that since the camera captured the picture in jpg that it is already damaged (a little) that i can at least save this on cd in this format and then if i choose to edit save it as a

psd

or a tiff.

Thanks for all the Help & Happy Holidays

"Stephen H. Westin" <westin*> wrote in message

"Yves Alarie" <rd50> writes:

Everything you are trying to do is incorrect.

1. Where did you learn that jpg corrupts files? Nonsense.

Not "nonsense". JPEG is lossy compression: you don’t get back the same bits you put into it. Once that happens, of course you can’t get back to the original bits. But that may not be a problem, as JPEG is designed to throw away information that isn’t visible, anyway. Except, of course, that the degree of compression (and hence the degree of loss) is adjustable; it’s certainly possible to make visible changes to an image by saving it as JPEG with too much compression.
That said, it seems that every time a JPEG image is loaded, modified, and saved again can lose more data. Probably not much, but something to think about if you are processing images through many steps. In that situation, lossless image storage may be worthwhile.

2. Your camera is sRGB, your video display is sRGB.

Well, they are RGB. Quite possibly not sRGB, which is a specific

standard.

All printers are CMYK.

Except those that are CMY, of course :).

There is no sense in saving a picture in CMYK. XP (or any photo

software)

sends your sRGB file to your printer, it is translated automatically

to

what

your printer can understand.

If you converted to .tif you will see that these files will be about

10

times the size of .jpg.

Depending on compression level in the JPEG, of course. And the content of each image. I just saved an image in TIFF with LZW compression; it was 518728 bytes. The same image in JPEG (quality 10 from Photoshop 6) was 232158 bytes. I think you’ve overstated your case. Almost as badly as "JPEG corrupts files".

The only time you want to save in .tif is when you want to edit the

file

many times and "save as" many times.

Exactly.

We used .tif in the old days because resolution was poor and "save as"

jpg

many times would degrade the image. These days are gone with cameras

of

2 MP

and above.

I’m not sure why I should be glad to lose detail in, say, a 3MP image. If I pay for a 3MP camera, it would be nice to preserve all that detail.

If you want to convert the .tif files back to jpg you can use this

free

batch converter:
http://www.irfanview.com/

Here is a way to do your own experiment.

This used to be correct, in the days of poor resolution digital

cameras

and

scanners. Things have changed dramatically and unless you want to

print

very

large (by large I mean more than 12 x 18) from a pro shop there is absolutely no advantage to save tif files over jpg.

Except you said that editing/saving many times is a situation where you want lossless compression.

The first point is, every time you "Save as" a jpg there is a little

loss

and artifacts introduced, so if you edit a picture and you Save as

many

time, there is some degradation with each Save as, but not with Save

if

you

use Save to save your changes as you are editing(even if you don’t do anything to the picture and you Save as just to change the name of the

file,

it is the Save as that is the problem).

Huh? How do you know this?

So if you plan to edit the file many
times, keep it in tif until done and then save it as jpg. Since you

can

always saved it back as tif for further editing, no problem.

Exactly.

The second point is, can you see the difference? Only you can tell, no amount of info will convince you. So you do the experiment yourself.

It

has

been done many times. Here is how to do it.
Take one of your jpg file, right click on it and click on Copy. Hold

the

Ctrl key down and press the letter V. This will make a new file in

your

folder "Copy of filename.jpg (note there is no degradation when you do

this,

since you don’t open the file and Save as, you only copied it). Now.
1. Open this file in your photo editor and Save as. Give it the name

Copy of

filename 1.jpg
2. Open Copy of filename 1.jpg, Save as and change 1 to 2.
3. Continue doing this until you Save as this file 15 times.

I’m not sure this will show the problem. Certainly closing, re-opening, and re-saving will.

<snip>

And yes, the experiment sounds like a valid one.

—
-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.

Enjoyed your reply and questioning my opinions.
Hope you can join us offering solutions here.

"Stephen H. Westin" <westin*> wrote in message

"Yves Alarie" <rd50> writes:

Everything you are trying to do is incorrect.

1. Where did you learn that jpg corrupts files? Nonsense.

Not "nonsense". JPEG is lossy compression: you don’t get back the same bits you put into it. Once that happens, of course you can’t get back to the original bits. But that may not be a problem, as JPEG is designed to throw away information that isn’t visible, anyway. Except, of course, that the degree of compression (and hence the degree of loss) is adjustable; it’s certainly possible to make visible changes to an image by saving it as JPEG with too much compression.
That said, it seems that every time a JPEG image is loaded, modified, and saved again can lose more data. Probably not much, but something to think about if you are processing images through many steps. In that situation, lossless image storage may be worthwhile.

2. Your camera is sRGB, your video display is sRGB.

Well, they are RGB. Quite possibly not sRGB, which is a specific standard.

All printers are CMYK.

Except those that are CMY, of course :).

There is no sense in saving a picture in CMYK. XP (or any photo

software)

sends your sRGB file to your printer, it is translated automatically to

what

your printer can understand.

If you converted to .tif you will see that these files will be about 10 times the size of .jpg.

Depending on compression level in the JPEG, of course. And the content of each image. I just saved an image in TIFF with LZW compression; it was 518728 bytes. The same image in JPEG (quality 10 from Photoshop 6) was 232158 bytes. I think you’ve overstated your case. Almost as badly as "JPEG corrupts files".

The only time you want to save in .tif is when you want to edit the file many times and "save as" many times.

Exactly.

We used .tif in the old days because resolution was poor and "save as"

jpg

many times would degrade the image. These days are gone with cameras of

2 MP

and above.

I’m not sure why I should be glad to lose detail in, say, a 3MP image. If I pay for a 3MP camera, it would be nice to preserve all that detail.

If you want to convert the .tif files back to jpg you can use this free batch converter:
http://www.irfanview.com/

Here is a way to do your own experiment.

This used to be correct, in the days of poor resolution digital cameras

and

scanners. Things have changed dramatically and unless you want to print

very

large (by large I mean more than 12 x 18) from a pro shop there is absolutely no advantage to save tif files over jpg.

Except you said that editing/saving many times is a situation where you want lossless compression.

The first point is, every time you "Save as" a jpg there is a little

loss

and artifacts introduced, so if you edit a picture and you Save as many time, there is some degradation with each Save as, but not with Save if

you

use Save to save your changes as you are editing(even if you don’t do anything to the picture and you Save as just to change the name of the

file,

it is the Save as that is the problem).

Huh? How do you know this?

So if you plan to edit the file many
times, keep it in tif until done and then save it as jpg. Since you can always saved it back as tif for further editing, no problem.

Exactly.

The second point is, can you see the difference? Only you can tell, no amount of info will convince you. So you do the experiment yourself. It

has

been done many times. Here is how to do it.
Take one of your jpg file, right click on it and click on Copy. Hold the Ctrl key down and press the letter V. This will make a new file in your folder "Copy of filename.jpg (note there is no degradation when you do

this,

since you don’t open the file and Save as, you only copied it). Now.
1. Open this file in your photo editor and Save as. Give it the name

Copy of

filename 1.jpg
2. Open Copy of filename 1.jpg, Save as and change 1 to 2.
3. Continue doing this until you Save as this file 15 times.

I’m not sure this will show the problem. Certainly closing, re-opening, and re-saving will.

<snip>

And yes, the experiment sounds like a valid one.

—
-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.

"WStoreyII" wrote in message

I have seen a lot of debat on this issue today since posting this,
since the general concensus seems to be that since the camera captured the picture in jpg that it is already damaged (a little) that i can at least save this on cd in this format and then if i choose to edit save it as a psd or a tiff.

I have taken this approach. I save the camera’s jpg image file to Tiff format. Then I make any necessary adjustments and resave to the Tiff files. I then archive these Tiff files on CD-R and convert back to jpg when needed. Continually re-saving jpg’s will cause the image to degrade over time. Experiment for yourself by saving a image file in two formats, one in tiff and the other in jpg. Then make 4-5 sets of image adjustments, re-saving between each adjustment. You will discover
for yourself which is the better method.

Yves Alarie wrote:

…there is some degradation with each Save as, but not with Save if you use Save to save your changes as you are editing…

Hmm, I did a little test:

Open a drawing, zoom way way way in close and saveas under a different filename… when it asks for the jpeg compression ratio, slide the bar way over to 1 or 2 & you can see the effect of the compression as you slide (PS 5.5). Hold it there for a moment to allow the preview to calculate. Now, as soon as you click OK to make the save, it returns to the good quality so what you have in the editor is still tiff quality (unless you crash). Save or saveas doesn’t matter.

I normally save minor crops & adjustments for photo shoots in jpeg (under a different file name) and I agree it doesn’t usually matter much except very large prints as long as the quality is above 7 or 8. I keep the original just in case. If it’s special I’ll save at a quality of 12 which is still smaller than a tiff & it’s nice not to have all different file types (perhaps a trivial point).

Where it does matter though is with a big simple gradually transitioning sky, especially if you are going to do some increase in contrast with that. Really detailed fussy pictures will not be affected as much and won’t compress as well in file size either.

Also, photoshop remembers the jpeg quality setting I used last if it was last saved in photoshop. If direct from the digicam, it doesn’t know what setting to use and takes the last ratio I used before shutting down photoshop (and rebooting?). But I can close an image that was saved at a ratio of 2, shut down PS & reopen it, do a blurr & saveas remembers the 2 setting. I’m a little unclear exactly what to expect here but those are my results.

For important professional products, the hard drive space is cheap though.

"Yves Alarie" <rd50> wrote in message

Just do the experiment yourself.
You have a 3 MP camera. You have the option to save in .jpg or .tif. Take the same picture, one in jpg and one in tif

<snip>
All the canon cameras I have looked at(digital Compacts) only have one format :
Still image:
JPEG (Exif 2.2 compliant)

Are the cameras that can do "tif" only the expensive ones ?

Many digital cameras can capture an image in an uncompressed .tif format.

The whole point of saving an image as a jpeg is to reduce memory usage. Since the jpeg format was introduced, we’ve been able to greatly decrease the size of the image while giving up an acceptable level of image quality. However, a .tif will be a better image, and it will be a much larger file. And, even if you have lots of memory in your camera, the time it takes to capture a 15MB+ tif and transfer it to the memory will probably be unacceptable in most instance. My Sony DSC-V1 will take a 5mp .jpg @ ~2MB or a .tif @~16MB and the difference will be apparent, but only upon zooming into the image or with a very very good printer. Since the camera ships with a 32MB memory stick, few would use the .tif format on a regular basis.

Since the .tif file is so much larger than an acceptably compressed .jpg you will probably rarely, if ever, take images in that format. If you are not already looking for a high end camera, it is likely that you are not taking photos that will require the .tif format.

Ctk

"Sunny" wrote in message

"Yves Alarie" <rd50> wrote in message

Just do the experiment yourself.
You have a 3 MP camera. You have the option to save in .jpg or .tif. Take the same picture, one in jpg and one in tif

<snip>
All the canon cameras I have looked at(digital Compacts) only have one format :
Still image:
JPEG (Exif 2.2 compliant)

Are the cameras that can do "tif" only the expensive ones ?

I should have said "check if you can shoot jpg and tif" with your 3 MP camera.
I have a Sony S70, 3.2 MP. Three years old.
I can shoot jpg or tif. The newer 5.0 MP cameras can shoot jpg, tif or RAW.

However, when you shoot tif or RAW, expect huge files and a long time to save and be ready again to take the next picture. Not practical. So, if you want the absolute best for large prints, shoot in tif or RAW. There is no point of shooting in jpg and then converting to tif in your computer to then print. The conversion of a jpg to tif will not improve anything.

"Sunny" wrote in message

"Yves Alarie" <rd50> wrote in message

Just do the experiment yourself.
You have a 3 MP camera. You have the option to save in .jpg or .tif. Take the same picture, one in jpg and one in tif

<snip>
All the canon cameras I have looked at(digital Compacts) only have one format :
Still image:
JPEG (Exif 2.2 compliant)

Are the cameras that can do "tif" only the expensive ones ?

"Yves Alarie" <rd50> writes:

Enjoyed your reply and questioning my opinions.
Hope you can join us offering solutions here.

Didn’t I suggest that he conduct the experiment? I just wanted to correct some serious errors in your article:

1. The notion that JPEG "corrupts files" isn’t "nonsense", but a simplification of something that really happens.

2. Cameras and monitors don’t all implement the sRGB color space.

3. TIFF files aren’t, as a rule, 10 times the size of a JPEG of the same image.

<snip>

—
-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.

I certainly agree with your points. Particularly saving the jpg at the highest quality. No point in doing anything less.
You may have a camera with the option of shooting jpg or tif. This is an experiment worth doing.
Place the camera on a tripod and take the exact same picture in jpg and tif. You can now really compare the difference when opening the photo on your screen.
Particularly if you have dark hard edges against a white background. You can see the typical jpg jaggies instead of a solid dark color edge. "Paul Furman" wrote in message

Yves Alarie wrote:

…there is some degradation with each Save as, but not with Save if you use Save to save your changes as you are editing…

Hmm, I did a little test:

Open a drawing, zoom way way way in close and saveas under a different filename… when it asks for the jpeg compression ratio, slide the bar way over to 1 or 2 & you can see the effect of the compression as you slide (PS 5.5). Hold it there for a moment to allow the preview to calculate. Now, as soon as you click OK to make the save, it returns to the good quality so what you have in the editor is still tiff quality (unless you crash). Save or saveas doesn’t matter.

I normally save minor crops & adjustments for photo shoots in jpeg (under a different file name) and I agree it doesn’t usually matter much except very large prints as long as the quality is above 7 or 8. I keep the original just in case. If it’s special I’ll save at a quality of 12 which is still smaller than a tiff & it’s nice not to have all different file types (perhaps a trivial point).

Where it does matter though is with a big simple gradually transitioning sky, especially if you are going to do some increase in contrast with that. Really detailed fussy pictures will not be affected as much and won’t compress as well in file size either.

Also, photoshop remembers the jpeg quality setting I used last if it was last saved in photoshop. If direct from the digicam, it doesn’t know what setting to use and takes the last ratio I used before shutting down photoshop (and rebooting?). But I can close an image that was saved at a ratio of 2, shut down PS & reopen it, do a blurr & saveas remembers the 2 setting. I’m a little unclear exactly what to expect here but those are my results.

For important professional products, the hard drive space is cheap though.

Thank you .

"Yves Alarie" <rd50> wrote in message

I should have said "check if you can shoot jpg and tif" with your 3 MP camera.
I have a Sony S70, 3.2 MP. Three years old.
I can shoot jpg or tif. The newer 5.0 MP cameras can shoot jpg, tif or

RAW.

However, when you shoot tif or RAW, expect huge files and a long time to save and be ready again to take the next picture. Not practical. So, if you want the absolute best for large prints, shoot in tif or RAW. There is no point of shooting in jpg and then converting to tif in your computer to then print. The conversion of a jpg to tif will not improve anything.

<snip>

On Wed, 24 Dec 2003 07:29:27 GMT, "Sunny"
wrote:

"Yves Alarie" <rd50> wrote in message

Just do the experiment yourself.
You have a 3 MP camera. You have the option to save in .jpg or .tif. Take the same picture, one in jpg and one in tif

<snip>
All the canon cameras I have looked at(digital Compacts) only have one format :
Still image:
JPEG (Exif 2.2 compliant)

Are the cameras that can do "tif" only the expensive ones ?

Sort of. But Canon tend to not do TIff. They do jpeg and RAW. And RAW is better than Tiff because you’re getting the "raw" data.

—

Hecate

veni, vidi, reliqui