How big?

[Dave6223]

I was thinking.......................

If you had the rescources, if you vwere to make a print from a 10mp DSLR without fitting it onto an A4 page, how large would it be?

I'm guessing larger than A3 but I really don't know.

Over to you.

Dave

[Frog]

With printing prices as low as they are I'd give an A2 a try or maybe even bigger.
I wouldn't use the local drugstore or walmart but use one of the good on line printers.
Mpix and Adorama do well with Mpix being the better with more options.

How big do you really want?
Also consider that big pictures are usually viewed at a distance that doesn't show flaws that would show with a magnifying glass.
That's my amateur opinion anyway.

[random one]

i have a 40D which is a 10 megapixel camera. i shoot in .RAW and when i convert my pics to jpeg they are at 350 DPI.

-at 350 dpi my 10 mp images are about 7.5 x 11 inches.
-if i drop the dpi down to 200 they end up being about 13 x 19.5 inches.
-at 150 dpi they are 17 x 26 inches ( a bit bigger than A2).

it all depends on the dpi.


but one thing i'm wondering is:

if i printed an 11 x 14 of a shot at 350 dpi (which measures about 7.5 x 11 on my screen), and printed another 11 x 14 of the same shot at 225 dpi (about 11.5 x 17 on my screen), would i see a difference in the prints?

- and that question wasn't just a test for everyone, i am actually wondering which way would be better for printing enlargements.

[Medley]

if i printed an 11 x 14 of a shot at 350 dpi (which measures about 7.5 x 11 on my screen), and printed another 11 x 14 of the same shot at 225 dpi (about 11.5 x 17 on my screen), would i see a difference in the prints?

The short answer is "yes, probably". Depending on the printer, the 350 ppi print will look a bit softer (less sharp) than you originally intended, and the 225 ppi print will look significantly sharper (probably overly so) no matter which printer you use- unless you account for these things ahead of time in post-processing.

Notice I used ppi- pixels per inch, and not dpi- dots per inch. That wasn't a typo. They'll be different in both cases. I've done a thorough study of sharpening techniques, specifically as they apply to sharpening for print. In the process, I've made some interesting discoveries:

Any pp person worth their salt knows that you should resize an image before doing any sharpening. If you reduce the size of an image after sharpening, then you consequently reduce the width of the sharpening halos. The result is a general softening of the image. The oppositte is true for enlarging an image- you get wider sharpening halos, and an effect of oversharpening.

All printers have a "native resolution". This is the resolution they print at under normal circumstances. The native resolution of a printer can be determined by sending an image with sharpening halos of a specific size to the printer, and measuring that against the actual physical size of the halos in the print (a tedious process requiring a micrometer). For example, an image @300 ppi with sharpening halos that are 3 pixels wide ( which, by the way, does NOT correspond to a radius of 3, though the two vary directly)SHOULD result in a print with sharpening halos that are 1/100 of an inch wide. If they are not, then the image has been resized to match the printer's native resolution.

From here on, the information applies ONLY to laser printers. Other types (such as halftone printers) do not apply.

As it turns out, the native resolution of almost all (laser) printers is at or about 300 dpi. The ONE exception is Epson, who's laser printers have a native resolution close to 360 dpi. If you can resize the image to match these resolutions for the size print you want, the sharpening halos will be neither reduced nor enlarged.

If you send an image to a printer at a resolution lower than it's native resolution, it's best to use a harmonic of the native resolution. For a Canon printer, that means that a resolution of 150 is good, 200 is better, and 300 is best. Those numbers are 180, 240, and 360 respectively for an Epson. The printer will have an easier time resizing such images, and the quality is generally a bit better.

An interesting side note here: it takes a fine eye for detail to tell the difference between a 300 dpi print from a Canon and a 240 dpi print from an Epson. The average person will see no loss of quality.

Lastly, the more distance there is between the eye and the image, the lower the resolution needs to be to provide the illusion of continuous tone. It makes a great deal of difference where sharpening is concerned, as keeping the sharpening halos consistent with visual acuity provide the best results. I only mention it here because people have a tendency to stand farther away from larger images, so you can get away with less resolution. If there is some magic formula for determining that exact resolution necessary, I haven't discovered it. Like so much in photography, it's largely a matter of experimentation.

- Joe U.

[random one]

wow medley, that has to be the most in depth answer i've ever heard.

thank you for the info. i definitely learned a few things that will come in handy.

and for what it's worth (i don't know if it makes a big difference) i work and print at a photo-lab that uses a Noritsu 3213 laser printer (technically they call it a "mini-lab"). i think it's native resolution is 300 dpi, but it isn't your standard home printer. it prints with a laser and runs the prints through chemical baths and then through a dryer.

does the type of printer matter (even in this case) or is it just the dpi (ppi)?

thanks again.

[Medley]

It will vary a bit from printer to printer, and I can't speak for your model. However, if it helps, I do my prints on a Noritsu 34-Pro, and use a 300 dpi native resolution. So I would venture a guess that the 3213 would as well.

A mini-lab eh? Do you, by chance, work at Costco? I happen to know for a fact that they favor Noritsu printers. Just curious.
- Joe U.

[random one]

It will vary a bit from printer to printer, and I can't speak for your model. However, if it helps, I do my prints on a Noritsu 34-Pro, and use a 300 dpi native resolution. So I would venture a guess that the 3213 would as well.

A mini-lab eh? Do you, by chance, work at Costco? I happen to know for a fact that they favor Noritsu printers. Just curious.
- Joe U.

i actually work at wal-mart. i've heard they use the same printing system as costco, but i haven't been to a costco in a long time.

[Medley]

LOL, that's fair- I work at Costco, and haven't been to a wal-mart in a long time.

Here's a sharpening tip: measure the width of your display. Not the entire monitor, just the part that is the actual display.

Multiply by 75

Find the screen resolution for your monitor who's width is the closest to that number, and switch to that screen resolution.

Open your image. Resize to 300 dpi x whatever size print you want.(example: a 4x6 inch print would need to be 1800x1200 pixels)

Set the view to 25%

Go to Unsharp Mask. Set the radius to 3, the threshold to 2, and adjust the amount until the image on the screen looks good.

Save the image and print it.

You should get a very sharp print, possibly with one or two minor issues. You may have to do some minor tweaking, be it should definitely be in the ballpark. I'd be interested in your opinion.

- Joe U.

[freygr]

Well, a good sharp image will look good up to 150 DPI. I've sold some of my printed images at this resolution. But allot depends on the printer! At 150 DPI a 10M pixel image is about 17 x 25 inches

[Sushigaijin]

Any pp person worth their salt knows that you should resize an image before doing any sharpening.

I generally agree with your post. HOWEVER, I've had very good luck with a two stage sharpening technique, sharpening first at full resolution and then again at final resolution. It works extremely well for high-detail photos, which I take lots of. I wouldn't dream of downsizing without it, but I would not enlarge using that technique.

There are many different sharpening techniques for many different applications and even between cameras the techniques need to vary.

To answer the OP question, I've printed at 12x16 (10 mp) and think it wouldn't be a problem to go higher.

[Medley]

I agree with you completely Erik. Actually, I use a three-pass sharpening technique: Once for input (which covers both the specifics of the camera and softening due to interlacing of the image), once for image content, and once for output ( which covers softening due to conversion from square pixels to round dots of ink as well as tuning the sharpening to a specific printer.)

I've adopted this because I've never found a single pass sharpening technique that adequately addresses all of these issues. However, I've also long since given up extolling the virtues of a multipass technique- most folks are too ingrained in the conventional wisdom of 'sharpen once, and only once'.

So please consider my remarks to be directed toward the one-pass mindset, with image content being the main subject of focus.

- Joe U.

[Fucia]

WOW I hope to understand what you all are talking about someday!!

[Sushigaijin]

WOW I hope to understand what you all are talking about someday!!

You will. Joe threw a bunch of really solid information out for you. The most important fragment is that you really must understand the way that digital printing works in order to maximize your prints. Back in the days of film it wasn't so important because most people didn't have access to post-processing. Now that it's commonplace, it's much easier to get good enlargements and prints. Understand the mechanics and the question won't be "how big," it will instead be "how do I get it so big." Not "if" but "how."

[Dave6223]

Wow! Thanks everyone for the amazing answers. Photoplus cinformation tells me that my snaps at original size are around 38" X 30".

The answers on sharpening were extremely interesting and gives me lots to go at.

[freygr]

A 3 mega pixel shot can be printed billboard size. The trick is the viewing distance. Most posters are only printed at 72 dpi. The larger the image is the greater the viewing distance is.