getting correct image quality

Design Discussions general design discussion
1

Hi

I have a question regarding getting the correct quality image so i can send some work via e-mail to a company.

I have rendered an image in solidworks at 300dpi and when i import it into photoshop under ‘image size’ it says that the image is only 72dpi

i am using photoshop for the presentation and lettering and then compiling each display board into one pdf document. I know standard screen resolution is only 72 or 96dpi but if they want to print them off they will be of a poor quality. Sending them at 300 dpi makes the whole file quite big, around 10mb.

What is the best way to do this so they dont look low res at their end and why when i open my solidworks file in photoshop does it say the image is onlt 72dpi???

please help

2

Many times, my digital camera will bring in images that are 28" x 21" or something like that, and at 72 dpi. Well, if you tweak the image size in Photoshop by un-checking the “Resample Image” option, then up resolution to 300 dpi, you’ll note that your image dimensions are now 6 3/4" x 5" or so. A lot of programs do the enormous inches thing, but when you up the resolution (after unchecking Resample Image") you will get an image that is a more normal size and should print acceptably. I always try to stay as close as possible to 300 dpi for any images or scans I work with. You can always reduce the quality of the output in Distiller (ie. Press or Screen settings, for example), which reduces the size of the .PDF. An ebook PDF document will print acceptably for review, and it shouldn’t be too awfully big. I doubt you would be getting hired based on how a .PDF prints, but you’re right in that you should want it to look as professional as possible given the media and format.

Good luck,

mothy

3

You shouldn’t be using Photoshop for the type unless the board is just one big photo with callouts or something like that. Use a layout/illustration program – your file size will be smaller and your type will look better.

I don’t think I can help on the Solidworks question, but I would check the image size of the actual dimentions in pixels. It might be that you have all the pixels you need and Photoshop is determining the dpi and physical image size ddifferently than Solidworks. In other words you may be able to resize to 300 dpi and still have a large enough image dimensionally – just guessing, though.

4

I posted at the same time as gaygaruda – my second comment is the same as his comment (though his may be clearer!).

5

try 150 dpi, and compress at around 6-7

also, irfanview is a free graphics editor that will do this quickly and easily.

6

Agreed. 150dpi is all you need.

It doesn’t matter what you do in Photoshop, only your settings in Acrobat.
When printing to an acrobat file, click “preferences” choose the “Adobe PDF Settings” tab, then click “edit” next to the Default settings.

Here you’ll see options to automatically downsample and apply compression to your color images. Play with this until you have a reasonably small file (trial & error.)

7

I, too, suggest using a layout program, such as Quark (I use that) or InDesign. It manages printing much more reliably, and you can manipulate text with much greater control. Plus, when you get out in the real world, your company’s printer isn’t going to kill you for sending him your annual report in Photoshop.

mothy

8

thanks for all the speedy replies but just one more point.

i will have no need to print them at all so that wont matter to me. i just want to be sure that if the company i send them to does print them, then they will be off high enough quality without being massive file. my pdf will contain my cv, concept sketches, one main board and a exploded view board (5 A4 pages in total). the problem is that to view a whole page in acrobat means you have to view at around 50% zoom. At this level the overall boards look a bit pixelated but if you zoom in, the main image looks very crisp but then you cant see a whole board at one time. This is my problem in a nutshell. Maybe this cant be helped.

Heres the main board so you can see the image for yourself

9

It’s your display settings in Acrobat. Go to (assuming you are using 6.0) Edit>Preferences>Smoothing and check type, line art, and (most importanty) images.

Hope that helps.

10

best way to do it is to render to file as a large jpeg in solidworks. what you can do is in the photoworks menu hit render to file icon, when diag box opens you check inches box and set the dots at 400 dots per inch. then w=5.33in and h=4 fixed aspect ratio 1.33:1. set it to custom quality at 100 (maximum). then save it.

once in photoshop when you open the file, you don’t need to dbl clk the bkgrnd layer to turn it into a regular layer, leave it as is. just go to image size and change the resolution to 150. once you have done that do the image size again this time reduce the size, ie %25 or letter size. then you go to file> print w/preview, pick the scale to fit and then do the page set up. then save the file as pdf. that way it’s ready for print using pdf format at 150 dpi.