Resizing issues

[Lady Lark]

Hi, could someone please help me? I am having trouble understanding resizing a photo. The photo Im trying to resize currently has demensions of 3840x2560. I am having trouble figuring out the proper pixels vs dpi for both posting on web and for print. Say I wanted to post it here and print an 8x11, what would I need to resize it to?

[pnodrog]

The best way of doing it will depend on the software you have available. To get a meaningful answer let us know what software you want to use. You will need to crop as the proportions you are starting with would end up as a 8x12.

[xpatUSA]

Hi, could someone please help me? I am having trouble understanding resizing a photo. The photo Im trying to resize currently has demensions of 3840x2560. I am having trouble figuring out the proper pixels vs dpi for both posting on web and for print. Say I wanted to post it here and print an 8x11, what would I need to resize it to?

Please understand that a single file saved from your original image will not do for both web posting and printing. Your post seemed to indicate that you hoped it would.

For posting on the web, forget all about dpi or ppi and just think pixels. Think about your target viewers' monitors or tablets or smart-phones. With modern monitors, they are quite commonly 1920 pixels wide but mine is 1280. Not sure what phones are up to these days but mine is 800x600 px or so. Also, we should think of people's bandwidth from their internet provider and their connection speed. Nobody will thank you for posting your 3840x2560px image full size at 100% JPEG quality

For here, around 1280px wide would do and I personally use 90% JPEG quality for a shot intended to impress but much less in size and quality for simple illustrations. So there you go: downsize your masterpiece to 1280px with bicubic or Lanczos, then final edit and save as JPEG, quality 9 if you use Elements.

Some editors have a 'save for the web' option, which some here use and some don't (I don't).

Others will be along shortly to tell you what they do . . . .

As to printing, I don't. But 3840px printed 10" wide is 384 ppi (printer pixels per inch - 'dots' is ambiguous). You can go two ways - let the printer dialog do the re-sizing by selecting 'letter size' and let it get on with it, or you can re-size the image to 3000 wide and set the print dialog to 300 ppi. For some printers (Canon?) that might be 3600 wide and 360 ppi.

A printing expert will be along shortly to provide any corrections required . . .

[pnodrog]

What ever you do and however you do it please keep your full size version and just save the reduced sizes as copies with a different names.

[IzzieK]

I too will wait until you indicate what sort of medium you want to display your image to and what software you are using for your pp. Please try to understand that screen and actual physical print are different beasts altogether. In Photoshop, there is a window one can open (Ctrl + Alt+I) and you will noticed that at the top selections are the size of your photo. Look down on the second portion where you will see the size of the photo when printed. As you change your size number, also look at the very top of the window and you will find that the size changes too. +1 to Paul's comment too.

[Manfred M]

As others have noted, PPI (Pixels Per Inch) is just a scaling factor and with most modern screens, this is going to be somewhere around 100. Many editing programs that have a "save for the web" function still default to 72 ppi which was used for the old CRT (cathode ray tube = picture tube) style screens that were in use 20 years ago. The exact value is quite irrelevant.

When posting on the web you are also looking to balance off a couple of other factors; speed of loading (don't forget people in the developing world or in remote rural areas in developed countries have slower connections) and of course, anything on the internet can be ripped off and used by others without your permission. I tend to follow their lead for most of my images and the maximum dimension I post with will be 1600 pixels (width for an image that is in landscape format or height for an image in portrait format) and let the software work out the second dimension for me.

Printing is a touch more tricky as the dots-per-inch (dpi) actually do make some difference, as this is really somewhat dependent on the printer being used for output. Epson photo printers have a native resolution of 360 dpi whereas Canon and HP ones are 300 dpi, so use of one or the other number makes sense. If you are having your image printed commercially, you are going to want to know this (and some other data, like the icc profile of the paper / printer combination they will be using). If they don't know, 300 dpi and as sRGB jpeg is the safest route to go.

I never save my screen and upload files and get rid of them right after upload or printing. I tend to have store my working output as standardized Photoshop psd files.

[Lady Lark]

I am using Lightroom since I havent figured out photoshop yet. I am looking to upload my photo to sites like this one and facebook. The print is for family and would be printed commerially since I would be having it framed at the same time. I didnt mean to sound like I was hoping to be able to post online and print from the same file. I know I would have to have more then one.

[Lady Lark]

By the way thank you...... I forgot to say that in the last one

[pnodrog]

Lightroom is particularly good in managing/adjusting sizes etc. You can use either the export, print or web modules to achieve the output files you need. I tend to use export for most things but the other options are equally good.

It will still be best to use the crop option in the develop module to achieve the desired crop ratio. Adobe have lots of online tutorials and videos that will cover most of what you need to know.

[ST1]

Jessica, have a look at the video in the following link which covers printing using Lightroom. You should be able to find Julieanne Kost's other videos for Lightroom on Adobe TV I found them useful when starting out with Lightroom.

LINK

[Lady Lark]

Thanks everyone! This was alot of help.

[mrinmoyvk]

What if I give my full size image (6000 x 4000) to print on paper 15"x10" wide using a printer that supports 300 ppi ?
How does it affect the quality? Do I need to resize the image to 4500 x 3000 before printing on 15 x 10 paper to get the exact 300 ppi to get the best quality output?

[davidedric]

No, you don't need to resize. The 300dpi is the "native" resolution that the printer accepts in the file you pass to it. It bears no relation at all to the actual dots of ink that the printer deposits. The printer will take care of it all for you.

Dave