WOW thank you for your reply!
the placed image’s Effective Resolution is 294
the actual PPI is 72
and the pdf export settings - I tried normal pdf and interactive pdf in 300 dpi and less, in all cases the photoshop elements came out jaggady
I can't seem to understand - how come I use an identical sized document both in indesign and in photoshop but still objects placed from Ps in IND are way bigger ?
If the actual ppi are given as 72ppi you may want to check the resolution in the Image Size dialog again.
Is the image rotated in Indesign?
What are the Transparency Flattening settings?
Could you post a screenshot of the image in Photoshop at View > 100% and of the pdf in Acrobat at a size where the pixelation becomes very clear?
The second screenshot seems to have been down sampled and therefore be useless.
What are the exact pdf settings you use when exporting from Indesign?
Why are you using PSD files for these things?
You should do these symbols on Illustrator, save as AI files and place those in InDesign.
If you use vectors in Photoshop, you have to save those files not as PSD, JPG, TIF, but you should save them as Photoshop PDF or Photoshop PDP, both can retain vectors as vectors and the output will be crispy, with the other file types you will get jaggy results as you experienced and higher file sizes from InDesign. But better is to do it in AI.
Good point, doing these images as vector data should be advantageous indeed.