scanning resolution (DPI) for a 3x5 or 4x6 to enlarge to 8x10?

I've been reading around on this one, but I cant find a consistent
formula...

I have a ton of 3x5 and 4x6 35 mm prints to be scanned.. Not all of
them (or hardly any) will be needed to be enlarged to 8x10, but I'd
like to have enough DPI to be able to print these at 8x10 should I
decide to.

The printer they will be scanned/printed on is the Canon MP830
(9600x2400 dpi)...

I had scanned an 8x10 recently at 300dpi.. this resulted in a 2mb jpg
file...

Before, I had done a bunch at 300dpi.. but now I'm thinking perhaps I
should pick a number more in between 300-600.. say 400?

Right now my photos from my digital camera are about 3.1 MP.. or about
1.10 MB each..

(Side question.. anyone know the typical modern 35mm Megapixel
equavilent number, ie: is it really around 12 MP?)

So I'd like to have a dpi, that I could set the scanner at and do them
all the same, allowing for decent 8x10 enlargements (at least 3 MP in
quality if not, closer to film, but perhaps under 3mb each)..

Anyone have any thoughts?

Thanks

In article .com,
says...
I've been reading around on this one, but I cant find a consistent
formula...

I have a ton of 3x5 and 4x6 35 mm prints to be scanned.. Not all of
them (or hardly any) will be needed to be enlarged to 8x10, but I'd
like to have enough DPI to be able to print these at 8x10 should I
decide to.

The printer they will be scanned/printed on is the Canon MP830
(9600x2400 dpi)...

To be precise, DPI is a measure of printer capability, PPI is a measure
of image resolution.
I had scanned an 8x10 recently at 300dpi.. this resulted in a 2mb jpg
file...

JPEG file size is a highly relative figure, depending on level of
compression, it could vary alot.
8x10 at 300ppi is about 23MB in TIFF format.

Before, I had done a bunch at 300dpi.. but now I'm thinking perhaps I
should pick a number more in between 300-600.. say 400?

300PPI at actual print size is a good all around rez for a printed image

Right now my photos from my digital camera are about 3.1 MP.. or about
1.10 MB each..

3 MP won't give quite 300 ppi at 8x10 size...

(Side question.. anyone know the typical modern 35mm Megapixel
equavilent number, ie: is it really around 12 MP?)

Highly debatable subject, since digicam images and scanned images are
quite different in many characteristics.
Mainly for your question, scanning from prints is a very poor
comparision to begin with, since prints contain MUCH less information
than the film from which they were made.

So I'd like to have a dpi, that I could set the scanner at and do them
all the same, allowing for decent 8x10 enlargements (at least 3 MP in
quality if not, closer to film, but perhaps under 3mb each)..

Anyone have any thoughts?

Thanks

Scan your 3x5/4x6 at 600ppi, then resize to 8x10, which will give you
300 ppi or higher. You can then downsample to exactly 300 ppi if you
wish. Don't save as JPEG, but use TIFF or other uncompressed format. You
do know to not keep changing a file and resaving as JPEG, yes?

Much more info available at Wayne Fulton's fine site, scantips.com,
including a nice image/scanning size calculator.

Also, this newsgroup is pretty much dead; much better to post at
comp.periphs.scanners.

MM

On Feb 20, 11:02 pm, MoiMoi wrote:
In article .com,
says...

I've been reading around on this one, but I cant find a consistent
formula...

I have a ton of 3x5 and 4x6 35 mm prints to be scanned.. Not all of
them (or hardly any) will be needed to be enlarged to 8x10, but I'd
like to have enough DPI to be able to print these at 8x10 should I
decide to.

The printer they will be scanned/printed on is the Canon MP830
(9600x2400 dpi)...

To be precise, DPI is a measure of printer capability, PPI is a measure
of image resolution.

I had scanned an 8x10 recently at 300dpi.. this resulted in a 2mb jpg
file...

JPEG file size is a highly relative figure, depending on level of
compression, it could vary alot.
8x10 at 300ppi is about 23MB in TIFF format.

Before, I had done a bunch at 300dpi.. but now I'm thinking perhaps I
should pick a number more in between 300-600.. say 400?

300PPI at actual print size is a good all around rez for a printed image

Right now my photos from my digital camera are about 3.1 MP.. or about
1.10 MB each..

3 MP won't give quite 300 ppi at 8x10 size...

(Side question.. anyone know the typical modern 35mm Megapixel
equavilent number, ie: is it really around 12 MP?)

Highly debatable subject, since digicam images and scanned images are
quite different in many characteristics.
Mainly for your question, scanning from prints is a very poor
comparision to begin with, since prints contain MUCH less information
than the film from which they were made.

So I'd like to have a dpi, that I could set the scanner at and do them
all the same, allowing for decent 8x10 enlargements (at least 3 MP in
quality if not, closer to film, but perhaps under 3mb each)..

Anyone have any thoughts?

Thanks

Scan your 3x5/4x6 at 600ppi, then resize to 8x10, which will give you
300 ppi or higher. You can then downsample to exactly 300 ppi if you
wish. Don't save as JPEG, but use TIFF or other uncompressed format. You
do know to not keep changing a file and resaving as JPEG, yes?

Much more info available at Wayne Fulton's fine site, scantips.com,
including a nice image/scanning size calculator.

Also, this newsgroup is pretty much dead; much better to post at
comp.periphs.scanners.

MM


Thanks for the tips... So your saying, if I intend to downsample my
600dpi scanned print later on.. to save as Tiff, since its
uncompressed, makes sense. This could make for very large storage
though, as I'll have hundreds of 4x6/ 3x5's I'll be scanning.
(Unfortunately I dont have the orginal negatives or a scanner that
does negative scanning).

Perhaps in my case, I should just do the 600, save as jpg with the
least compression setting.. although I'll take a look at the site and
calculator you mentioned.

Thanks

On Feb 21, 9:57 am, "markm75" wrote:
On Feb 20, 11:02 pm, MoiMoi wrote:





In article .com,
says...

I've been reading around on this one, but I cant find a consistent
formula...

I have a ton of 3x5 and 4x6 35 mm prints to be scanned.. Not all of
them (or hardly any) will be needed to be enlarged to 8x10, but I'd
like to have enough DPI to be able to print these at 8x10 should I
decide to.

The printer they will be scanned/printed on is the Canon MP830
(9600x2400 dpi)...

To be precise, DPI is a measure of printer capability, PPI is a measure
of image resolution.

I had scanned an 8x10 recently at 300dpi.. this resulted in a 2mb jpg
file...

JPEG file size is a highly relative figure, depending on level of
compression, it could vary alot.
8x10 at 300ppi is about 23MB in TIFF format.

Before, I had done a bunch at 300dpi.. but now I'm thinking perhaps I
should pick a number more in between 300-600.. say 400?

300PPI at actual print size is a good all around rez for a printed image

Right now my photos from my digital camera are about 3.1 MP.. or about
1.10 MB each..

3 MP won't give quite 300 ppi at 8x10 size...

(Side question.. anyone know the typical modern 35mm Megapixel
equavilent number, ie: is it really around 12 MP?)

Highly debatable subject, since digicam images and scanned images are
quite different in many characteristics.
Mainly for your question, scanning from prints is a very poor
comparision to begin with, since prints contain MUCH less information
than the film from which they were made.

So I'd like to have a dpi, that I could set the scanner at and do them
all the same, allowing for decent 8x10 enlargements (at least 3 MP in
quality if not, closer to film, but perhaps under 3mb each)..

Anyone have any thoughts?

Thanks

Scan your 3x5/4x6 at 600ppi, then resize to 8x10, which will give you
300 ppi or higher. You can then downsample to exactly 300 ppi if you
wish. Don't save as JPEG, but use TIFF or other uncompressed format. You
do know to not keep changing a file and resaving as JPEG, yes?

Much more info available at Wayne Fulton's fine site, scantips.com,
including a nice image/scanning size calculator.

Also, this newsgroup is pretty much dead; much better to post at
comp.periphs.scanners.

MM

Thanks for the tips... So your saying, if I intend to downsample my
600dpi scanned print later on.. to save as Tiff, since its
uncompressed, makes sense. This could make for very large storage
though, as I'll have hundreds of 4x6/ 3x5's I'll be scanning.
(Unfortunately I dont have the orginal negatives or a scanner that
does negative scanning).

Perhaps in my case, I should just do the 600, save as jpg with the
least compression setting.. although I'll take a look at the site and
calculator you mentioned.

Thanks- Hide quoted text -

- Show quoted text -

I took a look at the calculator.. so if my original is 4x6 and I want
8x10 size.. I set those values.. then choose the print resolution.. if
300dpi.. then this is 600dpi scan.. if the print resolution is 600dpi
then i would need a wopping 1000 dpi scan resolution? Seems rather
crazy.

I'm actually confused because the specific specs on the max DPI for my
MP830 Canon list 9600 x 2400 dpi as the dpi.. so this is not 300 or
even 600dpi correct? IE: what print resolution would I put in the
calculator then?

Any thoughts?

Thanks

"markm75" wrote in message
oups.com...
On Feb 21, 9:57 am, "markm75" wrote:
On Feb 20, 11:02 pm, MoiMoi wrote:





In article .com,
says...

I've been reading around on this one, but I cant find a consistent
formula...

I have a ton of 3x5 and 4x6 35 mm prints to be scanned.. Not all of
them (or hardly any) will be needed to be enlarged to 8x10, but I'd
like to have enough DPI to be able to print these at 8x10 should I
decide to.

The printer they will be scanned/printed on is the Canon MP830
(9600x2400 dpi)...

To be precise, DPI is a measure of printer capability, PPI is a measure
of image resolution.

I had scanned an 8x10 recently at 300dpi.. this resulted in a 2mb jpg
file...

JPEG file size is a highly relative figure, depending on level of
compression, it could vary alot.
8x10 at 300ppi is about 23MB in TIFF format.

Before, I had done a bunch at 300dpi.. but now I'm thinking perhaps I
should pick a number more in between 300-600.. say 400?

300PPI at actual print size is a good all around rez for a printed
image

Right now my photos from my digital camera are about 3.1 MP.. or
about
1.10 MB each..

3 MP won't give quite 300 ppi at 8x10 size...

(Side question.. anyone know the typical modern 35mm Megapixel
equavilent number, ie: is it really around 12 MP?)

Highly debatable subject, since digicam images and scanned images are
quite different in many characteristics.
Mainly for your question, scanning from prints is a very poor
comparision to begin with, since prints contain MUCH less information
than the film from which they were made.

So I'd like to have a dpi, that I could set the scanner at and do
them
all the same, allowing for decent 8x10 enlargements (at least 3 MP in
quality if not, closer to film, but perhaps under 3mb each)..

Anyone have any thoughts?

Thanks

Scan your 3x5/4x6 at 600ppi, then resize to 8x10, which will give you
300 ppi or higher. You can then downsample to exactly 300 ppi if you
wish. Don't save as JPEG, but use TIFF or other uncompressed format.
You
do know to not keep changing a file and resaving as JPEG, yes?

Much more info available at Wayne Fulton's fine site, scantips.com,
including a nice image/scanning size calculator.

Also, this newsgroup is pretty much dead; much better to post at
comp.periphs.scanners.

MM

Thanks for the tips... So your saying, if I intend to downsample my
600dpi scanned print later on.. to save as Tiff, since its
uncompressed, makes sense. This could make for very large storage
though, as I'll have hundreds of 4x6/ 3x5's I'll be scanning.
(Unfortunately I dont have the orginal negatives or a scanner that
does negative scanning).

Perhaps in my case, I should just do the 600, save as jpg with the
least compression setting.. although I'll take a look at the site and
calculator you mentioned.

Thanks- Hide quoted text -

- Show quoted text -

I took a look at the calculator.. so if my original is 4x6 and I want
8x10 size.. I set those values.. then choose the print resolution.. if
300dpi.. then this is 600dpi scan.. if the print resolution is 600dpi
then i would need a wopping 1000 dpi scan resolution? Seems rather
crazy.

I'm actually confused because the specific specs on the max DPI for my
MP830 Canon list 9600 x 2400 dpi as the dpi.. so this is not 300 or
even 600dpi correct? IE: what print resolution would I put in the
calculator then?

Any thoughts?

Thanks


Use a little common sense and some (3rd grade?) math.

DPI stands for Dots Per Inch. Also can be expressed as PPI for Pixels Per
Inch.

Assume that you want to print an 8 inch x 10 inch print at 300 DPI or PPI.
To see how many pixels you need mulply inches by DPI (8 * 300) = 2400 pixels
for the narrow dimension. (10 * 300) = 3000 pixels for the long dimension.

So you need an image that is 2400 pixels by 3000 pixels. (Or larger).

Assume you are scanning a 4 x 6 inch print and want to print that 8x10 at
300 DPI.

To find the dpi to scan at, you divide the 2400 pixels you need by the 4
inches you have.
2400 /4 = 600 and and the 3000 pixels you need by the 6 inches you have.
3000/6 = 500. Scan at 600 dpi. (FYI a 4x6 will print 8 x12 after scanning at
600 DPI).

Scan at the higher result, the scanner can not scan each dimension at a
different dpi.

Another way is, if you want to print at 300 DPI, and to double the original
print size then double the scanning resolution.

If you scan a 4x6 at 300dpi, it will print 4x6 at 300 dpi
If you scan a 4x6 at 600dpi, it will print 8x12 at 300dpi.

Wayne Fulton has a printing & scanning calculator.
http://www.scantips.com/calc.html

--
CSM1
http://www.carlmcmillan.com
--

On Feb 21, 3:42 pm, "CSM1" wrote:
"markm75" wrote in message

oups.com...





On Feb 21, 9:57 am, "markm75" wrote:
On Feb 20, 11:02 pm, MoiMoi wrote:

In article .com,
says...

I've been reading around on this one, but I cant find a consistent
formula...

I have a ton of 3x5 and 4x6 35 mm prints to be scanned.. Not all of
them (or hardly any) will be needed to be enlarged to 8x10, but I'd
like to have enough DPI to be able to print these at 8x10 should I
decide to.

The printer they will be scanned/printed on is the Canon MP830
(9600x2400 dpi)...

To be precise, DPI is a measure of printer capability, PPI is a measure
of image resolution.

I had scanned an 8x10 recently at 300dpi.. this resulted in a 2mb jpg
file...

JPEG file size is a highly relative figure, depending on level of
compression, it could vary alot.
8x10 at 300ppi is about 23MB in TIFF format.

Before, I had done a bunch at 300dpi.. but now I'm thinking perhaps I
should pick a number more in between 300-600.. say 400?

300PPI at actual print size is a good all around rez for a printed
image

Right now my photos from my digital camera are about 3.1 MP.. or
about
1.10 MB each..

3 MP won't give quite 300 ppi at 8x10 size...

(Side question.. anyone know the typical modern 35mm Megapixel
equavilent number, ie: is it really around 12 MP?)

Highly debatable subject, since digicam images and scanned images are
quite different in many characteristics.
Mainly for your question, scanning from prints is a very poor
comparision to begin with, since prints contain MUCH less information
than the film from which they were made.

So I'd like to have a dpi, that I could set the scanner at and do
them
all the same, allowing for decent 8x10 enlargements (at least 3 MP in
quality if not, closer to film, but perhaps under 3mb each)..

Anyone have any thoughts?

Thanks

Scan your 3x5/4x6 at 600ppi, then resize to 8x10, which will give you
300 ppi or higher. You can then downsample to exactly 300 ppi if you
wish. Don't save as JPEG, but use TIFF or other uncompressed format.
You
do know to not keep changing a file and resaving as JPEG, yes?

Much more info available at Wayne Fulton's fine site, scantips.com,
including a nice image/scanning size calculator.

Also, this newsgroup is pretty much dead; much better to post at
comp.periphs.scanners.

MM

Thanks for the tips... So your saying, if I intend to downsample my
600dpi scanned print later on.. to save as Tiff, since its
uncompressed, makes sense. This could make for very large storage
though, as I'll have hundreds of 4x6/ 3x5's I'll be scanning.
(Unfortunately I dont have the orginal negatives or a scanner that
does negative scanning).

Perhaps in my case, I should just do the 600, save as jpg with the
least compression setting.. although I'll take a look at the site and
calculator you mentioned.

Thanks- Hide quoted text -

- Show quoted text -

I took a look at the calculator.. so if my original is 4x6 and I want
8x10 size.. I set those values.. then choose the print resolution.. if
300dpi.. then this is 600dpi scan.. if the print resolution is 600dpi
then i would need a wopping 1000 dpi scan resolution? Seems rather
crazy.

I'm actually confused because the specific specs on the max DPI for my
MP830 Canon list 9600 x 2400 dpi as the dpi.. so this is not 300 or
even 600dpi correct? IE: what print resolution would I put in the
calculator then?

Any thoughts?

Thanks

Use a little common sense and some (3rd grade?) math.

DPI stands for Dots Per Inch. Also can be expressed as PPI for Pixels Per
Inch.

Assume that you want to print an 8 inch x 10 inch print at 300 DPI or PPI.
To see how many pixels you need mulply inches by DPI (8 * 300) = 2400 pixels
for the narrow dimension. (10 * 300) = 3000 pixels for the long dimension.

So you need an image that is 2400 pixels by 3000 pixels. (Or larger).

Assume you are scanning a 4 x 6 inch print and want to print that 8x10 at
300 DPI.

To find the dpi to scan at, you divide the 2400 pixels you need by the 4
inches you have.
2400 /4 = 600 and and the 3000 pixels you need by the 6 inches you have.
3000/6 = 500. Scan at 600 dpi. (FYI a 4x6 will print 8 x12 after scanning at
600 DPI).

Scan at the higher result, the scanner can not scan each dimension at a
different dpi.

Another way is, if you want to print at 300 DPI, and to double the original
print size then double the scanning resolution.

If you scan a 4x6 at 300dpi, it will print 4x6 at 300 dpi
If you scan a 4x6 at 600dpi, it will print 8x12 at 300dpi.

Wayne Fulton has a printing & scanning calculator.http://www.scantips.com/calc.html

--
CSM1http://www.carlmcmillan.com
--- Hide quoted text -

- Show quoted text -

It was this calculator which I used...My confusion lies in the printer
dpi or ppi.. my color print resolution is 9600 x 2400 dpi .. so this
would seem to be much higher than 300 or 600..

On the average though, based on the numbers, i guess 600 dpi should be
my scanning resolution for 4x6 or 3x5 photos.. the calculator gives
unreasonable numbers for scanning resolution if you do it the right
way (thousands).

In article .com,
says...
On Feb 21, 3:42 pm, "CSM1" wrote:
"markm75" wrote in message

oups.com...





On Feb 21, 9:57 am, "markm75" wrote:
On Feb 20, 11:02 pm, MoiMoi wrote:

In article .com,
says...

I've been reading around on this one, but I cant find a consistent
formula...

I have a ton of 3x5 and 4x6 35 mm prints to be scanned.. Not all of
them (or hardly any) will be needed to be enlarged to 8x10, but I'd
like to have enough DPI to be able to print these at 8x10 should I
decide to.

The printer they will be scanned/printed on is the Canon MP830
(9600x2400 dpi)...

To be precise, DPI is a measure of printer capability, PPI is a measure
of image resolution.

I had scanned an 8x10 recently at 300dpi.. this resulted in a 2mb jpg
file...

JPEG file size is a highly relative figure, depending on level of
compression, it could vary alot.
8x10 at 300ppi is about 23MB in TIFF format.

Before, I had done a bunch at 300dpi.. but now I'm thinking perhaps I
should pick a number more in between 300-600.. say 400?

300PPI at actual print size is a good all around rez for a printed
image

Right now my photos from my digital camera are about 3.1 MP.. or
about
1.10 MB each..

3 MP won't give quite 300 ppi at 8x10 size...

(Side question.. anyone know the typical modern 35mm Megapixel
equavilent number, ie: is it really around 12 MP?)

Highly debatable subject, since digicam images and scanned images are
quite different in many characteristics.
Mainly for your question, scanning from prints is a very poor
comparision to begin with, since prints contain MUCH less information
than the film from which they were made.

So I'd like to have a dpi, that I could set the scanner at and do
them
all the same, allowing for decent 8x10 enlargements (at least 3 MP in
quality if not, closer to film, but perhaps under 3mb each)..

Anyone have any thoughts?

Thanks

Scan your 3x5/4x6 at 600ppi, then resize to 8x10, which will give you
300 ppi or higher. You can then downsample to exactly 300 ppi if you
wish. Don't save as JPEG, but use TIFF or other uncompressed format.
You
do know to not keep changing a file and resaving as JPEG, yes?

Much more info available at Wayne Fulton's fine site, scantips.com,
including a nice image/scanning size calculator.

Also, this newsgroup is pretty much dead; much better to post at
comp.periphs.scanners.

MM

Thanks for the tips... So your saying, if I intend to downsample my
600dpi scanned print later on.. to save as Tiff, since its
uncompressed, makes sense. This could make for very large storage
though, as I'll have hundreds of 4x6/ 3x5's I'll be scanning.
(Unfortunately I dont have the orginal negatives or a scanner that
does negative scanning).

Perhaps in my case, I should just do the 600, save as jpg with the
least compression setting.. although I'll take a look at the site and
calculator you mentioned.

Thanks- Hide quoted text -

- Show quoted text -

I took a look at the calculator.. so if my original is 4x6 and I want
8x10 size.. I set those values.. then choose the print resolution.. if
300dpi.. then this is 600dpi scan.. if the print resolution is 600dpi
then i would need a wopping 1000 dpi scan resolution? Seems rather
crazy.

I'm actually confused because the specific specs on the max DPI for my
MP830 Canon list 9600 x 2400 dpi as the dpi.. so this is not 300 or
even 600dpi correct? IE: what print resolution would I put in the
calculator then?

Any thoughts?

Thanks

Use a little common sense and some (3rd grade?) math.

DPI stands for Dots Per Inch. Also can be expressed as PPI for Pixels Per
Inch.

Assume that you want to print an 8 inch x 10 inch print at 300 DPI or PPI.
To see how many pixels you need mulply inches by DPI (8 * 300) = 2400 pixels
for the narrow dimension. (10 * 300) = 3000 pixels for the long dimension.

So you need an image that is 2400 pixels by 3000 pixels. (Or larger).

Assume you are scanning a 4 x 6 inch print and want to print that 8x10 at
300 DPI.

To find the dpi to scan at, you divide the 2400 pixels you need by the 4
inches you have.
2400 /4 = 600 and and the 3000 pixels you need by the 6 inches you have.
3000/6 = 500. Scan at 600 dpi. (FYI a 4x6 will print 8 x12 after scanning at
600 DPI).

Scan at the higher result, the scanner can not scan each dimension at a
different dpi.

Another way is, if you want to print at 300 DPI, and to double the original
print size then double the scanning resolution.

If you scan a 4x6 at 300dpi, it will print 4x6 at 300 dpi
If you scan a 4x6 at 600dpi, it will print 8x12 at 300dpi.

Wayne Fulton has a printing & scanning calculator.http://www.scantips.com/calc.html

--
CSM1http://www.carlmcmillan.com
--- Hide quoted text -

- Show quoted text -

It was this calculator which I used...My confusion lies in the printer
dpi or ppi.. my color print resolution is 9600 x 2400 dpi .. so this
would seem to be much higher than 300 or 600..

On the average though, based on the numbers, i guess 600 dpi should be
my scanning resolution for 4x6 or 3x5 photos.. the calculator gives
unreasonable numbers for scanning resolution if you do it the right
way (thousands).

Forget the "resolution" of the PRINTER, just use "best" quality.

You want image resolution of 300 at actual print size, and that's about
all there is to it, except for how you handle file archive. Oh, and one
more thing I always suggest....save your file with NO sharpening.
Sharpen at actual print size for the print you are making. Sharpening is
one function you really can't undo.

MM