Rndered image always in 72 res

[nilariver@gmail.com]

When we render an image in 3ds max whatever resolution output image always be in 72 resolution.Why it is like this ? What is the concept behind this ?

[DanGrover]

When we render an image in 3ds max whatever resolution output image always be in 72 resolution.Why it is like this ? What is the concept behind this ?

 

I'm fairly sure that a DPI (which I assume is what you mean by "72 resolution") is not baked into the image file - that is, the render will render at whatever pixel size you render it at. If this is then opened by a bit of software as 72dpi or 300dpi, it's up to the opener - but even then, dpi only makes sense in terms of printing.

 

If I'm wrong, please correct me.

[Jason Matthews]

It doesn't matter what the dpi is unless you are printing. Look at it like this:

 

dpi = resolution / image size

 

if you have an image that is 8"x10" at a resolution of 2400x3000 then the DPI is 300x300.

 

All you need to worry about is the resolution. If your resolution is like 1200x1200 and you are trying to print it as a 24x24 then your image will be poor because it is being printed at 50 DPI which is very poor quality. It always helps to know what your client's needs are prior to final renderings.

[francosd]

Max have a print size wizard that easily help you to render the image ypur client want

[Peter M. Gruhn]

I just want to get nit picky on some jargon.

 

These digital images are made up of pixels which have no inherent size. A pixel only has position and some value (usually an RGB colour triplet). It is convenient for some purposes to have an intended size associated with an image. This commonly involves specifying how many pixels should be used in an inch of presentation. This being the case, it is (a certain kind of) best to discuss images as having pixels per inch. PPI.

 

Printers go about making colour by making physical marks on paper. They may use fused toner, dye or wax, or... Since they only have (historically) four colours of ink to work with (CMYK) and (historically) only one fixed minimal sized mark, they use more or less of those dots of each color over a larger area of paper to represent the different colours they are capable of showing. The more smaller dots a printer can make the better the overall look of a print is. Hence printer manufacturers have been very keen on pointing out how many dots their printers can pack into one inch. This being the case, it is (a certain kind of) best to discuss physical printer operation and ink deposition in terms of dots per inch. DPI.

 

Scanners spit out classic digital images and IMO ought talk about PPI.

 

Printers and Photoshop etc. are sometimes used to simulate classic halftone images which are all about lines per inch. LPI.

 

Back in 1984 computers and pictures were pretty dodgy together on the desktop. Then Apple came out with the Mac. While they were doing that, they redefined the point to be 1/72nd of an inch. And they had a printer to go with it - pin impact on ribbon, iirc. The Mac screen had exactly 72 pixels per inch and the printer could do the same. Perfect WYSIWYG (barring dynamic range issues).

 

Later they put out a laser printer that would do 300dpi.

 

Since the first Mac's were strictly black/white, the correspondence between screen and printer did a nice job of blurring the idea between dpi and ppi (or not allowing it to be created yet?). If you wanted a gray image you did a line screen or dithering or something and you saw what the printer would make. No worries. Dots? Pixels? Same thing.

 

When you open an image in something that insists on having a ppi associated with an image (say Photoshop) and there isn't one, it will tend to revert back to 1984 and attach 72ppi to your image. This is even though a 72ppi monitor would likely sell very few units these days. Mine here are looking kind of chunky at 90ppi. Something like Max that doesn't have an inherent attachment to printing mayn't bother asserting a ppi for an image or will default back to 72ppi.

 

As computer displays and printer technology have diverged, it becomes more important, I think, to try to use these terms this way to (after that tedious rant, he can't be serious....) increase clarity.

[markf]

For my own thinking I use only PPI (just like the photoshop image size dialog does). Don't even bother thinking about DPI. When someone asks for a certain dpi image, just replace dpi with ppi and don't even have a discussion about it.

[mattclinch]

Peter's post should be stickied for all. It is essential info to communicate to a client but a difficult concept sometimes for them to grasp.

 

I think we should all start giving clients our images at 9 billion PPI just to mess with the head of whoever has to print it