Need help with PDF/font thing

Hi all.

I am not a professional graphic designer, so I apologize if this is a dumb question.

I have a PDF that I know is 300 dpi. When you view the PDF, even at high magnification, the text on it is sharp (i.e., there is no pixelation).

I need to crop the PDF. So I opened it in Photoshop and, for reasons I cannot understand, SOME (not all) of the text on the page becomes somewhat pixelated after I open it in Photoshop.

Once I save the new doc as a PDF, that same text it is much less crisp than the original.

I haven't changed the DPI or the color settings of the PDF in Photoshop.

Why does the very act of opening this doc in Photoshop cause this loss of sharpness? What am I doing wrong?

Thank you very much, in advance, for your help.

I would think that it's because Photoshop has rasterized the text upon opening it. (Sounds like it was originally created in a vector-based program such as Illustrator which is why it is sharp in the PDF) To minimise the pixellation, in the 'Import PDF' dialog box, you should check 'Anti-Alias' and set dpi to 300.

Two alternatives come to mind, both skipping PS altogether:
1. Open in Acrobat and crop
2. Open in a vector application e.g. Illustrator and crop

Of course, I realise these solutions aren't solutions to you if you don't have access to either program!

Since I posted this earlier, I have found out that what you said is exactly right, Wano. Is the rasterization (is that even a word). Indeed, the best solutions have been using Acrobat (as you suggest) and even using InDesign (placing the PDF into a blank InDesign document).

Thanks very much for your reply.