pahtspix

I know this Nikon D7200 24mpxl, has a native resolution of 6000x4000 pixels out of the camera..What sized print would that make in INCHES at that NATIVE resolution without up-rezzing the file? TIA guys! Pahtpix (Eddie Wiseman)

melismus Loc: Chesapeake Bay Country

At 300 dpi that is -- um -- er -- let me get my calculator -- 20 by 13.33.

LarryFB Loc: Depends where our RV is parked

I think you have to realize that it depends on what resolution you need in your print. Yes, a 6000 X 4000 pixel file will produce a 20 X 13.33 print at a print resolution of 300 dots per inch.

However, if you are willing to reduce the print resolution to 200 dots per inch, you can print a 30 X 20 inch photo.

A resolution of 300 dpi seems to be the standard for off set printing for magazines (not newspapers) or for the highest quality prints. A resolution of 200 dpi is usually considered as a good quality print as long as you don't look at the print too closely, but from a distance (think about a distance of 3 feet) it will look just perfect.

GoofyNewfie Loc: Kansas City

DPI (Dots Per Inch) and PPI (Pixels Per Inch) are two different things.
Not that you have to do it, but you can't even set DPI in Photoshop, only PPI.
You two responders should do yourself a favor and read something about the subject here:
http://www.uglyhedgehog.com/t-147932-1.html
Your math is right for this rough guide but the unit you used is incorrect.
BTW (By The Way) A lot of inkjet printers typically print at 1440 DPI and higher.

joer Loc: Colorado/Illinois

Bingo!

GoofyNewfie Loc: Kansas City

Almost.....

Bill_de Loc: US

As a starting point 300 PPI (Picture Element per inch) has been the standard for many years. It is considered the input that makes the printer so happy, that it will give you its best output.

The DPI (Dots per inch) is the number of 'specks' of ink per inch the printer will spit onto the paper. A single pixel, when put to paper, will be created with many specks of ink. Over the years as DPI increased, the printed colors have become much closer to what we are looking for.

melismus Loc: Chesapeake Bay Country

I did, and I thank you.

burkphoto Loc: High Point, NC

This 300 PPI figure is a bit of hogwash that came from GATF — the Graphic Arts Technical Foundation — way back in the 1990s. If you reproduce a photo in a magazine or book, on coated paper, with a 133 or 150 line screen, you really only need about 200 PPI in the original photo file. The 300 PPI standard was created to give photo editors the ability to enlarge a file by 50% without degradation!

I confirmed this in 1998 when we started making digital halftones and color separations for memory books at my school portrait lab. We tested hundreds of photos at various resolutions, made press tests, and confirmed that 200 PPI would do for 133 and 150 line screens, both in black-and-white and four-color reproductions.

Using higher resolution than 200 PPI did not resolve more detail in our books! We saved a TON on storage space, scanning time, network bandwidth, etc. by doing this testing. All those things were EXPENSIVE back then!

BUT, in the photo industry, the professional rule of thumb (thanks to a LOT of Kodak research) is that the eye can only resolve about 240 PPI from an 8x10 silver halide photographic print, at the diagonal of its viewing distance, 12.8 inches (round up to 13). So your 6000x4000 pixel image will enlarge quite well at 240 PPI to 25x16.67 inches (round down to 24x16 — it's a lot easier to remember!).

Many pro labs use 240 or 250 PPI as their standard for file submission.

What is interesting is that for MOST subject matter, you can take a 240 PPI 8x10 image, enlarge it to 16x20, and view it from 26 inches with no degradation in detail. You can also enlarge it to 32x40, view it from 52 inches, and see no degradation in detail. Of course, if you view the 32x40 at 13 inches, you will see the original pixels, and they won't be pretty... (So, as a practical matter, I would not be nervous about making 50x33.33 inch (or 48x32) prints from most sharp images coming from that 24 MP camera...)

For this reason, many folks believe we are at a point of diminishing marginal returns, once cameras get to around 24 MP. Go to 32, 36, or 50 MP, and you gain little, except at the EXTREME margins of cropping and/or enlargement of subject matter with lots of detail. And at those extreme resolutions, you had better have the best glass in front of that camera body that money can buy! With cheap or very old glass, you won't reap the benefits of the highest resolution sensors.

Well over 90% of today's images wind up on the Internet, on HDTV and 4K screens, or they are never printed larger than 12x18 inches. Unless you make very large prints, almost any of today's midrange to high end dSLR and mirrorless cameras will satisfy. We met and exceeded the capability of 35mm film quite a few years ago, and most lens makers have had to redesign and reissue their lens lines to keep up with improvements in sensors and electronics.

Oh, and that PPI vs DPI confusion? A pixel is a value in a file. A dot is ink (or dye) on paper. Cameras and post-processing software create pixels. Printers create dots to reproduce pixels. I can't say it any clearer. THEY ARE ALMOST NEVER THE SAME. But older folks in the graphic arts industry tend to use the terms interchangeably. The professionals in the photo industry are not confused!

lsimpkins Loc: SE Pennsylvania

Thanks Bill. Best exposition on this I have read.

CatMarley Loc: North Carolina

At 240 DPI (which makes very nice prints BTW) it is 25" x 17"

GoofyNewfie Loc: Kansas City

D'oh!!!!
There's that DPI thing again again!

Armadillo Loc: Ventura, CA

Well Goofy,

This subject has been argued 'till the cows come home, and nothing is going to resolve the argument.
You are correct in your statement, "DPI (Dots Per Inch) and PPI (Pixels Per Inch) are two different things."

Technically they are different values and identifiers.
A Pixel is a tiny light sensitive transistor that converts Photon energy into electrical energy. AKA Picture Element.
A Dot is a spot of ink squirted onto a sheet of paper.

PPI refers to how many photosensitive transistors can fit onto a specific sized photosensitive chip. If your photosensitive chip is 1 inch long and the transistors are small enough to fit 300 lengthwise into the chip you will have 300 PPI.

DPI refers to how many ink dots you can cram into 1 inch of paper, and still render details. In days of old, newspapers would print photographs using dots of ink, and we could count the dots that made up the rendering of the image.

The same holds true today in giant highway advertising signs. Sitting in your car, driving down the freeway at 65 MPH, you can see the contents of the sign clearly.

If you stopped and climbed up to the base of the sign you could not clearly see the contents of the sigh for all the dots making up the content. The farther you get away from the sign, the more the dots blend into a nice rendering of the advertisement.

What this all boils down to, PPI can be used to gauge the resolution of a device to capture an image electronically, digital camera to computer. DPI can be used to gauge the resolution of an image to a printer. Fortunately, technology has evolved to the point where the transistors on the photosensitive chip are close enough to the ink jets of inkjet printers to be equal. Our modern consumer printers perform the required calculations to convert the PPI values to DPI values to obtain the best quality printed document within the standards of current resolutions.

When it comes down to providing image products in the 'Real World', we must supply the imagery products in the format and resolution values the customer requires. If the customer wants DPI because his professional level printers require that value, we must provide DPI in the image product. Failure to do that and the customer will most likely say, "Very nice picture, but we cannot use your content."

Another area of contention is images on the WWW.
If you take an image straight out of the camera, save that image as a .jpg @ 300PPI/DPI, then go back to the camera image and save this image as a .jpg @ 72PPI/DPI with a modified file-name. Now, using your computer navigation tool read the file details for file-size on both image file-names you will see the 300DPI is much larger than the 72DPI file.
This may not be important if you only send pictures in e-mail, or upload to web servers in New York, and all your visitors/contacts live in New York with 100Mbaud internet connections. If you expect people in the rural countryside, who still have dial-up internet accounts, to view your web pages, or read your e-mail, they will delete your ultra slow content.
There are people in other parts of this world who pay for internet service by the bandwidth. The larger the image file in Mbytes the greater the bandwidth, and the more cost to that user.
Facebook is another good resource for viewing images uploaded in high resolution. Facebook re-sizes and resets the resolution according to internet standards because its content is available world wide. If you upload a high resolution image to FB, the rendered image may look poor on all monitors because FB uses a computer to automatically convert your high res picture to internet standards without regard to rendering quality.
If, on the other hand, you take the time and effort to re-size your image to what FB wants, and to 72DPI, FB will render your image to the highest level quality your computer can display.

A case in point in the medium we are now using. When we post an image to this forum, the server downsizes the image resolution to the WWW standards for rendering on a common computer system (your home computer). The server may also re-size the image to fit into the page format. The image thumbnails appear almost instantly when we open a post.

On the other hand, when we post an image and tick the "Store Original" box, this places a link in the post to download the original image file in its native size and resolution. Notice how long it takes to render that image on your computer. The higher the bandwidth of your internet service the faster the image will render on your monitor.

In the USA, most ISPs charge for the bandwidth service provided (5Mbaud - 100Mbaud), not for the bandwidth consumed.

So, once again it depends upon the end use of the images, as to how we save each image. In the early 1980s the internet industry agreed that a picture saved at 72DPI was the lowest resolution that could produce a high quality rendering on a CRT monitor. That value has not been revoked.

Michael G

CatMarley Loc: North Carolina

Dots per inch is something you set in your printer. You have to tell the printer how many dots you want it to place on every inch of paper.

TheDman Loc: USA

We all know what they're talking about.