300 DPI ?

Normaly i make graphics and animations for video and don’t need 300 DPI, but one of our clients asked us to make a model and render it on 300 DPI for professional printing.
How can i make a picture graphic with that much DPI.
When i blow it up in Photoshop it still is a 72 DPI picture blown up so…

Scotch

Hello

You need to know the “real” size of the desired image
Ex: if you need a 10 x 5 cm image you must render a 1200 x 600 image in
Blender

10 cm = 2.5 inches x 300 DPI = 1200 pixels

When you’ll open it in Photoshop or GIMP verify iin the image properties window
if the resolution values are correct

Bye

Well, it still is 72 DPI in Photoshop when i open the Image size dialog
:frowning:

Scotch

The resolution values won’t be correct… it will still be 72dpi, but you can change it in photoshop.

Stefano

When i change it from 72 to 300, i lose contrast, so i need to render it in full resolution, but how

Scotch

If you change the res, you also have to change the print size; you don’t want photoshop to resample the image. How big does the printed image have to be? If its 8inX10in, you have to render 2400px X 3000px. Then when you go into photoshop, you change the res to 300dpi and the printed size to 8x10.

one more:

1 - there is the desired print size (let’s say 10 x 10cm)
2 - this is ,in inches: 3,94 x 3,94in
3 - at 300 dpi (dots per inch), the pixel size of the image is: 1181 x 1181px
4 - this is the size you enter in blender for rendering.
5 - the image created from blender is set to 72 dpi, hence the printing size would be much larger (however low-quality)
6 - go in photoshop, open the image size dialogue and enter 300 dpi in the resolution field. the printing size goes down, to the desired 10 x 10cm.
7 - convert the image to CMYK and save as TIFF

yup, as solmax says

If you change only resolution you cannot loose contrast

Stefano

Make sure you uncheck "resample image’

I think you guys are mixing apples and oranges here. That 72 DPI refers to MONITOR resolution. 72 DPI is a typical setting for a 19 inch monitor at 1024x768 screen resolution. It’s calculated by measuring the usable horizontal (or vertical) viewing area and dividing the measurement by the corresponding screen resolution.

Example:

Horizontal: 1024 / 14.2 = 72.11267606 … 72 DPI
Vertical: 768 / 10.6 = 72.4528301 … 72 DPI

All you need to be concerned about is the IMAGE resolution.

DPI = Dots Per Inch == Pixels Per Inch

Centimeters to Inches Conversion_Factor == 0.3937
Inches to Centimeters Conversion_Factor == 2.54

With that in mind, the rest is simple math.

Yes, but he has to have the dpi and print size set for his client, so he must know how to do that in Phtotshop.

Image resolution is the only thing that is important, and you can figure the actual pixel count for your render using simple math (length in inches times the DPI). However some programs like Illustrator and Publisher when you “place” an image into the document will be the relative size as determined by the DPI, so instead of it being placed as the size they wanted it, will be huge on the page. But after they scale it down it will be the desired size and resolution.

72 DPI is the default in most programs if no DPI value is set in the header of the file. To change that in Photoshop, go to “Image”>“Image size…”. Uncheck “Resample Image” and then change the width, height, and resolution to the correct values. If you did your math right when you rendered the image, no resampling will occur but the values will now be correct for your client’s convinience when using the picture. The really important thing is that you make the image the right pixel size. Most peolple have used those programs enough that resizing an image is trivial.

I figured it out this way. I just opened a blender rendering in Photoshop and increased the dpi to 300. This increased the image size in pixels. I wrote down the new X and Y pixel size and plugged those numbers in blender. It took a little more than 24 hours to render :x. Then I opened the new render in Photoshop. Photoshop opens the image at 72 dpi by default so it is huge. Just change the image properties to 300 dpi and decrease the x and y size to what you need. It is that simple :smiley: .

This post is the perfect example why the world is such a mess, and why people can’t live in harmony

Maybe somenthing to do with the internal ear or the low intestinal tube, I don’t
know

I had the same issue a while ago and struggled. Finally I figured out a way to fix it. Photoshop will always bring in an image at 72 dpi so what I did in Blender was set my image res to as high as possible, which may sound nuts but it worked. I went with the over kill factor and set my res for ntsc to 10,000 by 8000 and picked TGA Raw because its lossless and removes the background if you need that. Then I opened it in photoshop and went to file image size and changed it to 400 dpi and thats it. Now the image is pretty crisp no matter how far you zoom in. Ofcourse it does pixelate if you go to far, but is perfect for the print you need. Then again I am a rookie to Blender so what do I know? LOL
Try it

I had the same issue a while ago and struggled. Finally I figured out a way to fix it. Photoshop will always bring in an image at 72 dpi so what I did in Blender was set my image res to as high as possible, which may sound nuts but it worked. I went with the over kill factor and set my res for ntsc to 10,000 by 8000 and picked TGA Raw because its lossless and removes the background if you need that. Then I opened it in photoshop and went to file image size and changed it to 400 dpi and thats it. Now the image is pretty crisp no matter how far you zoom in. Ofcourse it does pixelate if you go to far, but is perfect for the print you need. Then again I am a rookie to Blender so what do I know? LOL
Try it