one more time please

[jann1033]

sorry i know i have asked this and it just is not sticking in my brain

if i save a file as 8x10 or 8x12 300 resolution, largest file jpg, is that the largest print i can make from it? my photos from the camera are something like 14x9 so i usually crop them to 8x10/12 but if i ever want to make a larger print, am i shooting myself in the foot by doing that? i remember something about resolution not really mattering for something but that's as far as it goes

sorry but please spleak splainly and in small words so i can remember this
thanks

 

[MICKEY88]

I personally always keep my original file, then crop it to the size I want to have printed, that way I am sure the lab doesn't crop it differently than I would..

 

[MarkBarbieri]

spleak splainly and in small words

How 'bout I just type it really ssslllooowwwlllyyy.

if i save a file as 8x10 or 8x12 300 resolution, largest file jpg, is that the largest print i can make from it?

No, you can print it as big as you want. It might look like poop, but you can print it as big as you want.

Let's take the example of the 8 inch by 12 inch picture at 300 resolution. That picture is 2,400 dots by 3,600 dots. I got that by taking 300 dots per inch times 8 inches to get the total number of dots - 2,400. I then did the same for the 12 inch side.

To look reasonable, most printers want a picture that is between 180 dots per inch to 360 dots per inch. Too many dots isn't usually a problem because the printer will just ignore them. It'll just be slower.

If you print with too few dots per inch, you get the same effect as using a "digital zoom." The printer will have create new dots and guess at how they should look. For some pictures (typically those with lots of detail), this looks terrible. For others, it isn't too bad.

For your picture, if you went all the way down to 180 dots per inch (which is pretty low), you'd be looking at a print size of 13 1/3 inches by 20 inches. I got that by dividing the total number of dots (2,400 by 3,600) by 180 (what I am claiming is the lowest number of dots per inch that will look reasonable in most circumstances).

There are other factors that influence what is acceptable. You can upres the picture on your computer using some pretty elaborate algorythms. In English, that means that you can have the computer add more dots by doing some fancy guessing as to what dots it should add. This can help, but it can't work miracles.

The other big factor to consider is how closely you will view the print. That 180 dots per inch estimate assumes that you will be holding the picture in your hand and looking at it. If the print is on the wall behind the couch and no one is getting within 4 feet of it, you can get away with a lower resolution. The further back you get, the fewer dots per inch you need.

The cheap way to test is to select a part of the print, maybe a 2" by 3" slice and blow that up proportionally. Let's say that you wanted your 8"x12" picture to be printed at 24"x36" (tripling each dimension). Take a 2x3 section and print it at 6"x9". See how it looks at the distance you expect to view the big print. If it looks OK, make the big print. If it looks terrible, you just saved a bunch of ink and paper.

 

[mabas9395]

I've heard that billboards are printed in the neighborhood of 40ppi, so your 8x12 could really be blown up to 5ft x 7.5ft if you wanted to.

 

[Anewman]

Jann, I agree with MICKEY... What is wrong with keeping the original file? One never knows what size/ratio one might need in the future.

Also when you crop you do not need to enter a DPI, when you do enter a DPI the image is going to be resampled(UP OR DOWN depending on source and output). If you leave the DPI as is(blank) all you are doing is cropping but not resizing. Depending on how severe you crop the DPI marker(that is all it is) will be set accordingly.

I feel it makes things much easier to understand DIGITAL images if you forget about the inches and dpi and just talk pixels. The Canon 40d does not produce images 14x9 inches, it produces 3888 x 2592 images. After cropping said images might be 3000x2000(example) regardless of what you set the DPI/inches markers at.

I've heard that billboards are printed in the neighborhood of 40ppi, so your 8x12 could really be blown up to 5ft x 7.5ft if you wanted to.

Sure Billboards are printed at super low DPIs(I believe much lower than 40dpi), but most billboards are viewed at distances of several hundred feet away. If we were to view them at arms length we would obviously see the pixelazation. Who know maybe Jann has a large house.

 

[jann1033]

Jann, I agree with MICKEY... What is wrong with keeping the original file? One never knows what size/ratio one might need in the future.

Also when you crop you do not need to enter a DPI, when you do enter a DPI the image is going to be resampled(UP OR DOWN depending on source and output). If you leave the DPI as is(blank) all you are doing is cropping but not resizing. Depending on how severe you crop the DPI marker(that is all it is) will be set accordingly.

I feel it makes things much easier to understand DIGITAL images if you forget about the inches and dpi and just talk pixels. The Canon 40d does not produce images 14x9 inches, it produces 3888 x 2592 images. After cropping said images might be 3000x2000(example) regardless of what you set the DPI/inches markers at.


Sure Billboards are printed at super low DPIs(I believe much lower than 40dpi), but most billboards are viewed at distances of several hundred feet away. If we were to view them at arms length we would obviously see the pixelazation. Who know maybe Jann has a large house.

i do keep the original raw but maybe that isn't what you meant. the reason mainly i want to save something is if i edit anything i won't have to do it over and over
evidently i can just leave the dpi place blank though and not change anything but the size and guessing in that case i could crop it to what ever mutliple i want ie 16x24 and it won't matter...unless it would give me a larger file to save?.. i would like to have the best but most versatile photo saved so i can resize at will and not have to do anything else, if that is possible...

mark thanks for the slow typing, i got that and wrote it in my missing manual book

 

[Groucho]

My opinion (and I'm pretty forceful on this one ) is to ignore the DPI setting. Pretend it doesn't exist. This is a digital image, and the only thing that matters on your computer is the number of pixels. If you want maximum quality, then don't resize it up and don't resize it down. Crop if need be, but don't resize.

When you want it printed, tell 'em what size you want. (Or tell your software, if printing yourself.)

The "dpi" metadata stored in jpgs is 100% arbitrary. You can set it to 75 dpi, or 5,000, or 3. It doesn't affect the photo or how it'll look when printed.

This is one thing that I really hate about Photoshop. IMHO, they're coddling the photolab luddites who don't know a pixel from an exif and can only think in DPI. Photoshop, IMHO, should default to pixels for everything. Not inches. You can change it (and I recommend that you do) so that it defaults to whatever you want, so the hardcore paper-only folks could still set theirs to default to DPI and let the rest of the folks, who are working with mostly static images from a digicam, work without so much confusion.

 

[Anewman]

i do keep the original raw but maybe that isn't what you meant. the reason mainly i want to save something is if i edit anything i won't have to do it over and over

Ok I was not sure if you were talking about RAW files.

IMO if you do most of your corrections in your RAW converter you can produce the exact same image in seconds without having to repeat your corrections as most converters memorize the conversion settings.

But yes if you do something in photoshop after the conversion you would have to repeat THOSE steps.

evidently i can just leave the dpi place blank though and not change anything but the size and guessing in that case i could crop it to what ever mutliple i want ie 16x24 and it won't matter...unless it would give me a larger file to save?..

Leaving the dpi blank when cropping would not increase or decrease file size, if you crop half of the photo out you should expect a file about half the size of the uncropped one.

When you enter a DPI setting when cropping is when you increase or decrease file size. It all depends on original image size, severity of the crop and new dpi setting. But you are always resizing. It is very hard to explain but I will try to give an example.

If you crop out 50% of the original image to 8x10@300dpi, you would be left with a 7.2mp image(2400x3000). So now consider what the original file size was, and think about how the new image is 7.2mp even after you threw out half of the original pixels. That is some serious UPSIZING unless you started with a 14.4mp camera.

i would like to have the best but most versatile photo saved so i can resize at will and not have to do anything else, if that is possible...

Again IMO the most versatile and BEST saved photo is the original UNCROPPED one, and I am not even talking about RAW here.
If you need a 8x10 start with the original UNCROPPED photo and once you finish with that 8x10 delete it(while saving the original), and then when you need a 5x7(or other) you go back to that original UNCROPPED photo and produce your 5x7. I would not like to go to an already cropped 8x10 version of the photo to crop again to 5x7(or other), I would rather see the entire image. But that is just me.