Shipwreck Loc: Michigan

Being perhaps the least technically qualified individual on the planet, I have a question regarding DPI and Pixel count. I have been told a website designer needs photos for a site no larger than 72 DPI in a file no larger than 1.5 megapixel. If I were to take photos for the site (which I won't be doing) with my Nikon D300 and were to do the shots in JPEG, what image size option would I use, the default L, or M, or S?? I'm not looking for a detailed, technical explanation, just a down and dirty indication of which image size would best meet the website designer requirements. Thanks!!

johngault007 Loc: Florida Panhandle

It's strange that a "website designer" is requiring image files in any DPI at all. They are normally constrained by width/height and file size.

But, to answer in simple terms, since you won't be doing it, change to JPG (Small) and don't worry about all the other stuff.

Ysarex Loc: St. Louis

The 72 DPI value is entirely meaningless.

The 1.5 megapixel value is useful and tells you that your photo can't be much more than 1400 X 1050 pixels.

Joe

rehess Loc: South Bend, Indiana, USA

"DPI" is a meaningless measure in most cases; my cameras assigned a value of "300", but I ignore it in any case. For this web-site, any value of DPI and of dimensions are fine - it will fix them as the upload occurs.

Longshadow Loc: Audubon, PA, United States

I'm puzzled also.
The image display can be set to any size on the screen by the display code used. For example, a large image can be displayed in a browser as 240x360 pixels, or whatever size is desired.
I wouldn't care about dpi. Maybe concerned, that since it's for the web, a bazigabyte file is not needed and just takes up space on the server unnecessarily.

LWW Loc: Banana Republic of America

DPI and PPI are commonly read as being the same, and they aren't.

DPI, or Dots Per Inch, is a printing term and is a measurement of how many tiny dots can/will be printed on a line one inch long.

PPI, or Pixels Per Inch, is an input resolution vs an output resolution. A 1,000 X 1,000 ... 1 megapixel ... file wil print at 250 DPI to yield a 4 inch by 4 inch image. The same file will project a screen image of slightly more than 10 inch by 10 inch since the screen resolution is typically 96 PPI.

johngault007 Loc: Florida Panhandle

LS,
I totally agree with all of your statement, unless you are optimizing for dial-up customers....
The only reason I mentioned having a specific size, is to limit the distortion caused by using <width=xxxx height=xxxx>. I used to do it often for static web pages that had very strict sizes for some of the web graphics and placement on a page.

johngault007 Loc: Florida Panhandle

But this has no impact on website design.

CHG_CANON Loc: the Windy City

As mentioned already, 'DPI' is a meaningless attribute of pixel-based digital images. Alas, just like the human appendix, there's no way to build digital images without a DPI value, but 'dots per inch' is worthless and doesn't have any relevance as long as a positive number is provided between 1 and infinity.

Your D300 User Manual at page 60 defines the pixel resolution of the three quality options:

L - 4288 x 2848 (12MP)
M - 3216 x 2136 (6.9MP)
S - 2144 x 1424 (3.1MP)

Are you sure the designer said a file no larger than 1.5 megapixel? As you can see, you have no D300 quality setting that will create such a small 1.5MP resolution file. You'll also find there is nowhere within the D300 (nor any model digital camera) where you can change this nonsense DPI value. Your designer problem meant 1.5 megabytes.

Do you plan on editing your images? Or just sending them your images straight from the camera?

Your work will look best with even a small amount of editing. And, in your digital editor, you can manage both the pixel-size and file-size (byte) attributes of the resulting JPEGs you send to the site. See the details from this post, even if you skip the reading and just scroll to the examples of 'how' for a few popular editing software: Recommended resizing parameters for digital images

Longshadow Loc: Audubon, PA, United States

Ewe.
I've always built my own (and over a dozen other sites), keeping the same aspect ratio, except for my aspect ratio explanation page.
It's nice not to be restricted.
Hmmm. How long would a 20Meg image take over dial-up. Been SOOO long.

CHG_CANON Loc: the Windy City

Ask ChrisT

Longshadow Loc: Audubon, PA, United States

johngault007 Loc: Florida Panhandle

Yes it was THAT long ago!!!!

I think it was probably mid to late 90's that I was playing around with web graphic design and stuff. Coincidentally, that was around the last time I used dial-up

PHRubin Loc: Nashville TN USA

There may be some repetition, but for clarity:

Images are specified in (Mega)pixels - MP
Prints are specified in dots per inch (DPI)
Files are specified in (Mega)Bytes - MB

If you intend to print an image, it is up to YOU to determine what size and therefore what the resulting DPI will be. The DPI number we see in the EXIF data has meaning lost to the ages

Longshadow Loc: Audubon, PA, United States

Haha.
Yes, somewhere towards the end of the 90's we finally got a cable modem. I can barely remember dial-up, 96Kbaud...
I had a second phone line installed in the house for the computer.
But I'll recognize the connecting handshaking tones anywhere!