# Optimum Resolution for Printing Photos

Discussion in 'Digital Photography' started by SS, Nov 18, 2006.

1. ### SSGuest

I'm going to get 150 of my photo files printed at Asda as I can get them
done for 5p each at that quantity. Most of my files are at 7 mpx i.e. quite
large. The prints are 6" x 4" therefore is it actually worth sinding these
large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever the
ratio is to give 6 x 4. Digital prints do show a lot of detail and I don't
want to lose that but I can't see all the detail on a 7 mpx file being
visible on such a small print

SS, Nov 18, 2006

2. ### Roy GGuest

"SS" <> wrote in message
news:rSC7h.17827\$...
> I'm going to get 150 of my photo files printed at Asda as I can get them
> done for 5p each at that quantity. Most of my files are at 7 mpx i.e.
> quite
> large. The prints are 6" x 4" therefore is it actually worth sinding these
> large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever
> the
> ratio is to give 6 x 4. Digital prints do show a lot of detail and I don't
> want to lose that but I can't see all the detail on a 7 mpx file being
> visible on such a small print
>
>

Strange as it may seem, the number of pixels required to give a 6 x 4 print
proportion, have to be proportional to 6 x 4.

1280 x 960 does not acheive this.

The only difficult maths involved is to multiply the number of inches on the
long side by the required Ppi figure (300) and then to multiply the number
of inches on the short side by that same number.

The answer comes out at 1800 x 1200 pixels.

Roy G

Roy G, Nov 18, 2006

3. ### Tzortzakakis DimitriosGuest

Ï "SS" <> Ýãñáøå óôï ìÞíõìá
news:rSC7h.17827\$...
> I'm going to get 150 of my photo files printed at Asda as I can get them
> done for 5p each at that quantity. Most of my files are at 7 mpx i.e.

quite
> large. The prints are 6" x 4" therefore is it actually worth sinding these
> large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever

the
> ratio is to give 6 x 4. Digital prints do show a lot of detail and I don't
> want to lose that but I can't see all the detail on a 7 mpx file being
> visible on such a small print

Why not go to a local lab in your town and have them printed there?Where I
live you can take your memory card (any type) or a cd to a machine and
choose via touch screen size, picture, number of reprints etc.by yourself
and even know how much it costs before printing out the receipt and handing
it to a clerk.

--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
dimtzort AT otenet DOT gr

Tzortzakakis Dimitrios, Nov 18, 2006
4. ### Guest

SS wrote:
> I'm going to get 150 of my photo files printed at Asda as I can get them
> done for 5p each at that quantity. Most of my files are at 7 mpx i.e. quite
> large. The prints are 6" x 4" therefore is it actually worth sinding these
> large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever the
> ratio is to give 6 x 4. Digital prints do show a lot of detail and I don't
> want to lose that but I can't see all the detail on a 7 mpx file being
> visible on such a small print

, Nov 18, 2006
5. ### Guest

SS wrote:
> I'm going to get 150 of my photo files printed at Asda as I can get them
> done for 5p each at that quantity. Most of my files are at 7 mpx i.e. quite
> large. The prints are 6" x 4" therefore is it actually worth sinding these
> large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever the
> ratio is to give 6 x 4. Digital prints do show a lot of detail and I don't
> want to lose that but I can't see all the detail on a 7 mpx file being
> visible on such a small print

, Nov 18, 2006
6. ### Ron HunterGuest

SS wrote:
> I'm going to get 150 of my photo files printed at Asda as I can get them
> done for 5p each at that quantity. Most of my files are at 7 mpx i.e. quite
> large. The prints are 6" x 4" therefore is it actually worth sinding these
> large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever the
> ratio is to give 6 x 4. Digital prints do show a lot of detail and I don't
> want to lose that but I can't see all the detail on a 7 mpx file being
> visible on such a small print
>
>

Send the file as is and let the printer do the resizing. Or, you can
figure out how to resize them to 200 dpi for 4x6 prints as that is about
the best most photo machines print. Unless the time to upload is a real
problem, I would just send the file without resizing.

Ron Hunter, Nov 18, 2006
7. ### SSGuest

"Roy G" <> wrote in message
news:HmD7h.33493\$...
>
> "SS" <> wrote in message
> news:rSC7h.17827\$...
> > I'm going to get 150 of my photo files printed at Asda as I can get them
> > done for 5p each at that quantity. Most of my files are at 7 mpx i.e.
> > quite
> > large. The prints are 6" x 4" therefore is it actually worth sinding

these
> > large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever
> > the
> > ratio is to give 6 x 4. Digital prints do show a lot of detail and I

don't
> > want to lose that but I can't see all the detail on a 7 mpx file being
> > visible on such a small print
> >
> >

>
> Strange as it may seem, the number of pixels required to give a 6 x 4

print
> proportion, have to be proportional to 6 x 4.
>
> 1280 x 960 does not acheive this.
>
> The only difficult maths involved is to multiply the number of inches on

the
> long side by the required Ppi figure (300) and then to multiply the

number
> of inches on the short side by that same number.
>
> The answer comes out at 1800 x 1200 pixels.
>
> Roy G
>
>
>

Yes as I said "or whatever the ratio is" I just didn't have my calculator
handy. I would have to crop to the appropriate ratio.

SS, Nov 19, 2006
8. ### SSGuest

"Tzortzakakis Dimitrios" <> wrote in message
news:ejn6cd\$dsh\$...
>
> Ï "SS" <> Ýãñáøå óôï ìÞíõìá
> news:rSC7h.17827\$...
> > I'm going to get 150 of my photo files printed at Asda as I can get them
> > done for 5p each at that quantity. Most of my files are at 7 mpx i.e.

> quite
> > large. The prints are 6" x 4" therefore is it actually worth sinding

these
> > large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever

> the
> > ratio is to give 6 x 4. Digital prints do show a lot of detail and I

don't
> > want to lose that but I can't see all the detail on a 7 mpx file being
> > visible on such a small print

>
> Why not go to a local lab in your town and have them printed there?Where I
> live you can take your memory card (any type) or a cd to a machine and
> choose via touch screen size, picture, number of reprints etc.by yourself
> and even know how much it costs before printing out the receipt and

handing
> it to a clerk.
>
>
>
> --
> Tzortzakakis Dimitrios
> major in electrical engineering
> mechanized infantry reservist
> dimtzort AT otenet DOT gr
>
>

Cos it won't be 5p per print for sure!

SS, Nov 19, 2006
9. ### Scott WGuest

SS wrote:
> I'm going to get 150 of my photo files printed at Asda as I can get them
> done for 5p each at that quantity. Most of my files are at 7 mpx i.e. quite
> large. The prints are 6" x 4" therefore is it actually worth sinding these
> large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever the
> ratio is to give 6 x 4. Digital prints do show a lot of detail and I don't
> want to lose that but I can't see all the detail on a 7 mpx file being
> visible on such a small print

You will want to resize to about 300 ppi, which would work out of 1800
x 1200.

Whereas 1280 x 960 would make an ok print it would not be as sharp as
1800 x 1200. Going past 1800 x 1200 will show little if any
improvment.

Scott

Scott W, Nov 19, 2006
10. ### Bryan OlsonGuest

SS wrote:
> I'm going to get 150 of my photo files printed at Asda as I can get them
> done for 5p each at that quantity. Most of my files are at 7 mpx i.e. quite
> large. The prints are 6" x 4" therefore is it actually worth sinding these
> large files or should I re-size to say 1280 x 960 (1.3 mpx) or whatever the
> ratio is to give 6 x 4. Digital prints do show a lot of detail and I don't
> want to lose that but I can't see all the detail on a 7 mpx file being
> visible on such a small print

The most common native resolution for digital photo lab printers
is 300 pixels per inch, followed by 400ppi. If you can find what
machine they use, you can Google up its native resolution. In a
theoretical sense, the native resolution is the ideal for your
files, and some adjustments, sharpening in particular, are best
done at the final display resolution.

Alas, life seldom conforms to the ideal.

The lab will re-rasterize your photo automatically, and even if
you deliver a file in its native resolution, the resizing is
probably not a no-op. The cheap photo labs are set up to serve a
mass market. Most will automatically apply transforms such as
sharpening and contrast enhancement to give direct-from-the-camera
files more "pop". For adventures in getting exact results from
low-cost services, browse www.drycreekphoto.com.

At 5p per print, I suggest experimentation. One tip from my own
trials: tracking what parameters applied to each trial takes
significant diligence. Not that it's hard to get right; it's
just easy to get wrong.

--
--Bryan

Bryan Olson, Nov 19, 2006