Szie adequacy in emailing of photos

[JoeJ]

When I scan a photo, save it in PICTURES folder with photoshop CS6, and down-size it to, say, 300 Kb, and transmit it to a third party by email, as a jpg image, will the recipient be able to print it in, say, a double-postacrd size without revealing its pixels?

Many thanks for any help.

JoeJ

 

[gedstar]

Quick question why do you need to downsize it, can't you just send the full res image instead

 

[JoeJ]

Yes, of course I can, but I have been told to send images smaller than I MB to enable the recipient to print them without unduly burdening his computer system and at the same time obtain an image of, say, double-postacrd size without all the pixels showing on the printed picture.

For example, I have an image of 1.27 MB (969 pixels x 1356 pixels), which I have down-sized for transmission to 887 KB (800 pixels x 1120 pixels).

Does this make sense?

Thank you again.

JoeJ

 

[MrToM]

Technically speaking, according to your question, no. All digital images are pixel based so you'll always see the pixels regardless...its what the image consists of.

@gedstar has pointed out that there isn't any need to reduce the filesize....the image 'size' in terms of filesize is irrelevant...what's important is the dimensions of the image.....that is to say how many pixels there are in the image.

The so called 'quality' of a print is all down to how many pixels there are in the image....generally the more the better.

The 'size', (dimensionally, as in 'double postcard'), is determined by the resolution you specify for the image.

For example, a 300px wide image set to 300ppi will print out a 1" wide image.
The same image set to 1ppi would give a 300" wide image.

Pixels are the major importance when it comes to digital images....the actual 'filesize' has no influence, although it goes without say that generally it can be assumed the bigger the filesize the more pixels it has and therefore the better it is for printing.

Regards.
MrToM.

 

[Tom Mann]

1) When I Google "double size postcard", I get many different results. For example, see all the options in the following list of standard postcard sizes:
http://www.uprinting.com/standard-postcard-size.html

I realize that you used this terminology just as an example, but in the future, and to make this discussion concrete, can you simply give us the dimensions IN INCHES of the largest image that is to be printed (...on the postcard or however else it will be printed...).

While we are awaiting that info from you, let's assume that the largest image to be printed is 10 inches (on the long side), a nice round number to work with.

For reasonable quality prints, you should have at least 200 pixels per inch (ppi), and preferably, 300 ppi. This means that the pixel dimensions for such an image should be at least 2000 pixels ( = 200 ppi X 10 inches), and preferably 3000 pixels in the long dimension.

However, both of the examples you gave were well under this. So, you can see why I need you to be specific in terms of image size IN INCHES (or standard papers sizes as listed here: https://en.wikipedia.org/wiki/Paper_size ).
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2) With respect to your suggestion to down-rez images before transmitting, just don't do it. It's a complete anachronism. These days,ordinary people have devices (eg, cheap point-and-shoot cameras, cell phones, etc.) that routinely produce images that are 3000 or more pixels on a side. They also email them routinely. If your friend's email account can't handle an attachment of that size (ie, typical file sizes are several megabytes), then just send it to him using one of the free file sharing services like YouSendIt.com, Dropbox or any of the equivalent cloud based offerings from Google, Microsoft, etc.
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3) With respect to your concern about "seeing individual pixels", that's not going to be a problem for any commercial printing service, and not even for most home inkjet printers. This is because even if you send the printer an undersized file, the printer driver (ie, its software) will automatically up-rez your image before actually delivering it to the printer. If it up-rez'es your image, the worst you will see is a kinda-lumpy, slightly blurry image, but almost never will you see individual pixels (except in some very odd cases that aren't even worth talking about).
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4) You spoke about making relatively minor changes in the pixel dimensions of your images (eg, from ~1300 px down to about ~1100 px). Don't do this either. First of all, for the reasons I stated in #1 and #2, above, you don't need to, and you shouldn't make your image any smaller than it already is, and secondly, every time you resample an image (ie, change the pixel dimensions without cropping), you lose information and introduce a slight amount of blur. This is why Gedstar responded in the way he did.

HTH,

Tom M