On Sat, 8 Sep 2007 14:21:37 -0700,
wrote:
I have a Dell Photo AIO All In One Printer 922; includes printer, fax and scanner. According to the literature, it can print up to 4800 dpi. However, the scanner that’s built in can only scan up to 300 dpi (or I guess that should be samples per inch) which seems a little odd to me. Also, I created a 3" by 5.33" Photoshop file at 4800 ppi to test the quality of the print, but it is a huge 230 MB file. Not sure I want my files taking up this much space.
The 4800 dpi just sounds wrong to me. Does 4800 dpi sound normal or are they using the term out of context; i.e. really meaning that it will print a total of 4800 dots across the entire page?
Also, please let me know if you recommend any good books, tutorials, etc on the topic of image, scan, print and display resolution that could help me understand all of this.
I’m a novice regarding this topic, so it is very confusing to me at this point.
Thanks,
Hi Nolan! To make it simple, I would suggest that whenever you want to print an image, make sure that the image has a resolution of 300 dpi (or ppi which are interchangeable). You can get away with 240 dpi, but I prefer 300 dpi. Keep in mind that this is the resolution of the image itself.
Now when you print the image, the printer will have different dpi settings also, but most of them will usually give you the option of printing "Average….Good……Better….Best" or something like that. If the printing software allows you to enter ina specific number, like say 1200 dpi or 1440 dpi, then enter in the highest dpi that gives you the desired quality. You don’t necessarily have to enter in the highest setting that the printer has, just the setting that gives you the best results.
My printer has a 1200 dpi setting that I’ve used twice, and it uses a lot more ink than my usual 600 dpi setting, yet the 600 dpi setting results in excellent photo quality prints. I used the 1200 dpi setting on two small prints that seemed to have a trace of banding in them. This was the only time this occurred, and hasn’t happened since, so I never need to use the 1200 dpi setting.
When you scan a picture, then the dpi means something different. If you scan a picture that’s 2 inches high by 3 inches wide, and you want to print it out at 2 inches by 3 inches, then you should scan it at 300 dpi, since that’s what the printer needs to print it out as….2 x 3 at 300 dpi.
If you are going to scan this 2 x 3 picture, but you want to enlarge it to 4 x 6 inches when you print it, then you should scan it at 600 dpi. If you scan a 2 x 3 inch picture at 600 dpi, then resize it to 4 x 6 inches, then the picture will resize to 4 x 6 inches at 300 dpi. If you do this in PhotoShop, you will need to go to "Image"…."Image Size", and check the "Constrain Proportions" box, and uncheck the "Resample" box, then enter in the new size of 4 x 6 inches. When you do this, you will see that the "resolution" box will change from 600 pixels/inch to 300 pixels/inch, but that the "Pixel Dimensions" sizes at the top of the window will remain the same. What happens is that the picture had 600 pixels per inch and it covered a 2 inch by 3 inch area. When it’s resized, it now has 300 pixels per inch but it’s now covering a 4 inch by 6 inch area. It still has the same number of pixels, but they are spread out over a larger area, so you end up with less pixels per inch. Since you needed an image that was 300 dpi to send to the printer, the resulting 4 x 6 picture is now 300 dpi.
Talker