preparing images for printing

[mudman]

my brother and his partner want prints of my 14/11/16 images.
i have resized them to 16:9 format, and was wondering what else i can do to help get get best results
would increasing the number of dots per inch help, the current setting is 300 dpi? the reasons for asking this is that i don't know how large they want to print them.
also i hand held when taking them and with my unsteady hands iq probably suffered, even with shake reduction on.
i was thing of giving them a few different versions so they can discuss which ones to print for the result they want
any other help, and advise, would be much appreciated
cheers

[ameerat42]

Muddie.
3 Qs:
I guess you mean of the supermoon?
What sort are they, just moon in the sky, or with included landscape?
You mean you cropped them to 16:9 format rather than "re-sized" them?

1 A:
Here's what I'd do:
Ask them, "What size prints?"
Ask you, "Pixel size of original images?"

After that, more answers.
(Note: you can even skip asking them, as one size should do almost all.)

[mudman]

Muddie.
3 Qs:
I guess you mean of the supermoon?
What sort are they, just moon in the sky, or with included landscape?
You mean you cropped them to 16:9 format rather than "re-sized" them?

1 A:
Here's what I'd do:
Ask them, "What size prints?"
Ask you, "Pixel size of original images?"

After that, more answers.
(Note: you can even skip asking them, as one size should do almost all.)

these are the images my bro and co want


http://www.ausphotography.net.au/for...d-the-rain-bow
http://www.ausphotography.net.au/for...rom-14-11-2016

[ameerat42]

OK, ta. (Not supermoon, OK.)

Do you have versions of these that are NOT re-sized for posting here.
I would say about HALF the native camera output size.
Ie, half of 4672 pixels wide, or 2336 pixels.

That would give pretty good detail up to at least A3 print size (depending on other factors).
DO NOT re-sample the images back upwards if you have already down-sampled them for
posting here. Use (as near as possible) originals. The printers can then set whatever size your
bro wants. (At a pinch, you could even give them full size, but I think it would be unnecessary.)

NOTE: If after you have re-sampled the pics to HALF the camera size, you need to do more cropping,
just leave them at whatever they come out to. So, if you crop say to 2200 pixels, leave it at that.

Aside: It's odd that the haloing occurred during raw conversion.

[Mark L]

No epert here but it's my understanding that you can get away with more sharpening and noise with printed photos compared to the electronic screen.
300dpi should be okay. The few prints I've done at A# were 350dpi and was fine.
I wouldn't resize at all. The larger the dimensions the more you sharpen perhaps?
This all makes sense to me and hopefully some will correct me.

[ameerat42]

Mark. You don't have to set any DPI measurements, just a "reasonable" resolution to
conserve as much detail as possible for the desired final size print. If sending an image
file to a printer you only tell the printer what to set its parameters at - the DPI that it
will use to print a file o whatever size you have.

For the image file itself there is no DPI setting, though you can specify "Pixels per Inch", not that it
matters much. Even if you set the printing parameters in the image file to print at, say, 15cm x 10cm,
that is just squeezing more pixels into the unit of measure, but it's still not DPI. The image file is
"translated" by the printer into a "printer file" and DPI is (somehow) set there.

That is AFAIUI.

I also re-extend the invitation for a more accurate description.

[Mark L]

Mark. You don't have to set any DPI measurements,

So it's okay to send a file to a printer with zerodpi??

[ameerat42]

You're sending an image file. I don't see how you can set any DPI, is what I'm saying.

If it can be shown how, then I'm v. interested. Ie, what is a "dot" in DPI as far as "pixels" go?
Is a "dot" a pixel? I don't think it is. To me a "pixel" is the basic unit of an image file, while a "dot"
may be a basic unit of a printer file (ie, that stream of data that a printer understands).

To me a dot may cover 10 pixels of an image file, or it may require 3 dots to make up one pixel.

[mudman]

mark and am, my bad
i cs6 image size the default setting seem st be 300 PIXELS per inch not dots
if i increase the number oF PIXELS per inch will it improve image detail when printed

[ameerat42]

Not really. It's not just a matter of increasing the image size, but doing any appropriate PP
(sharpening, etc) that the change might require. IMO, the image size from your camera would be
sufficient (all else being equal) to produce poster-size (whatever that is) prints. As I said, unless
they really want that size, even half the native pixel size would do - if file size is an issue with the
printer firm.

>>Additional: I would not up-sample any images you've already down-sampled. Instead, work on
the originals again, doing whatever you did before, then save a version for printing. That can be
either at the same size, or re-sampled to, say, half normal size. <<

[enseth]

Muddie, at the risk of being over simplistic I wouldn't get to worried. Just use the high megapixel image that you have and it should be fine unless you're really blowing up the image to an enormous size. I print out a lot of images to 10"x15" and haven't had any resolution problems to date. The main trap I fall into is not allowing for image darkening when it's printed, ie it always comes out darker when printed than what it looks on your computer screen. This being the case it pays to go slightly brighter or increase the exposure a tad more than you normally would in PP prior to sending it to the printer. Not a very scientific answer I know but I'm just a simple sort of guy.

[ameerat42]

From a bit of "research" on the subject, one of the clearer references discussing
DPI and PPI...
https://imagescience.com.au/knowledg...en-ppi-and-dpi

[Mark L]

This could have been written by AK ....... http://www.vsellis.com/understanding...vs-web-images/

[arthurking83]

..... The main trap I fall into is not allowing for image darkening when it's printed, ie it always comes out darker when printed than what it looks on your computer screen. This being the case it pays to go slightly brighter or increase the exposure a tad more than you normally would in PP prior to sending it to the printer. Not a very scientific answer I know but I'm just a simple sort of guy.

This is simply a case of screen to printer calibration.
So many factors it's hard to pinpoint one reason for any discrepancy.
An easy(but probably incorrect) solution would be to brighten your screen to compensate, but of course this will only work for that given printer(the one that prints a bit dark).
On another printer using a different paper type the results may come out different again(or not).
If your printer = a home printer and you only use that, then you'll be fine calibrate them to match.
But if your printer = a printing service, but that printing service then changes to another, this can also vary depending on the reliability of the various services.

This could have been written by AK ....... http://www.vsellis.com/understanding...vs-web-images/

Nah! made too much sense .. so while it could have been written by me, it was in fact written by the anti-AK ... an author that makes sense, and does so in a concise manner too.

The article by vsellis is a good one to read.

Basically forget about PPI, it's use is best reserved for scanning.
DPI is the one to take note of for when doing your own printing.
If you use a printing service, then just hand them(or send them) the largest file you can without making any changes to PPI or DPI or nothing!

So, if your cameras image is 4000 pixels by 3000 pixels, send them a 4000x3000 pixel image. But you cropped it to 4000x2400 pixels to achieve a 16:9 landscape aspect ratio, then send them the 4000x2400 pixel file.

ps. mudman, you said you resized them to 16:9, but do you mean cropped them. Technically you can't resize them to 16:9, you resize the number of pixels in the image.
So lets say you're image example was as above(4000x3000) and you cropped to a 16:9 landscape format(to 4000x2400). That's cropped to 16:9

If you resized then you'd have taken the 4000x2400 pixel image and set it to 1000x600.
Resizing simply makes it available to the entire screen at a smaller file size.

If you resized it to 16:9 from that original 4000x3000 example above, then you have squashed the image, and it will be distorted in one plane now. The distortion effect for such a resize will be like stretching it laterally(sideways).

The difference between cropping to 16:9 and resizing to that same ratio is that obviously when you crop, you maintain the detail in the pixels remaining, but have deleted x amount of pixels(from 3000 to 2400 = 600 pixels) on one side.
When you resize to that ratio, what you'd have done is to turn those 3000 pixels into 2400 pixels. You haven't deleted those 600 pixels, you'd have compressed them, ie. distorted them or squashed them into that amount.
Hopefully you cropped to that 16:9 ratio.

So to re-iterate - once you have your image set the way you like, you then:

1/. resize only to display on the net(due to bandwidth) ie. speed. This will resize both the display of the image AND the actual file size. The new size of the image on a monitor is now set, but you can obviously tweak the file size(ie. the number of Mb/Kb) using various compression(quality) settings

2/. do nothing else if you want to print it. Don't set DPI's or PPIs(yet).
Keep it this way if you send the file off to Joe Printer to print it nice an larger for 'ya.
BUT!. if you have an uber printer at home and can print it for your brother, then you have two options.
2a/. set DPI in Ps and then print it using Ps. This last bit is important.
2b/. if you have an uber printer and prefer to use that uber printers uber software too, then don't set any DPI in Ps. You then set the quality level in the uber printers software, and it may be a DPI setting or it just may be a pre set quality setting like Ultra Photo or Uber Ultra Super Duper Photo or something like that.