Large format

[ishfaque.b]

Hi,

I need to design a billboard 12m by 3m.

I have a photo of 4000x 3000 px at 300 resolution.

What i did:

I created a new document in photoshop at 900 resolution

And I placed the photo directly in it without upsampling.

Does the 900 resolution file automatically convert the photo at 300 dpi since now it was placed in a 900 dpi file?

or Do I have to resize the photo and put it at 900 dpi before placing it in the 900 dpi file?

[c.pfaffenbichler]

I created a new document in photoshop at 900 resolution

What size?

If you placed the image as a Smart Object it could have been upsampled (but the result may be inferior to a Resampling with Image > Image Size with »Preserve Detail«) depending on your Preferences settings and the size and actual pixel dimensions of both files.

[ishfaque.b]

32.1 by 23 cm

[davescm]

Hi

It is impossible to answer your question as you have not stated the pixel size of your new file.

If it is still 4000px by 3000 px and the only change is from 300 dpi to 900 dpi then nothing in the image has changed.  The dpi value is just metadata (i.e. data that sits as a value in the file) which tells a printer driver how many pixels to use for one inch of printed output. It does nothing else.

Dave

[ishfaque.b]

doc size is 10 pecent scale..so 120cm by 30cm

[davescm]

Depending how big you placed the image - then it probably was scaled and as stated by c.pfaffenbichler will have used the default scaling algorithm from preferences.

You are creating a document of 42520 px x 10630 px. which is very high.

As per your other post - at what distance will this be viewed?

If it is a billboard to be viewed at say 12m distance then you are looking for a final resolution of 15ppi. At that distance, anything higher will not be visible to the human eye . So 15ppi would give you a requirement to work at a much more reasonable 7087 x 1772 px

This link may help explain :

What print resolution works for what viewing distance?

Dave

[ishfaque.b]

so what do i need to do? list the steps

[c.pfaffenbichler]

An article of resolution and viewing distance:

What print resolution works for what viewing distance?

so what do i need to do? list the steps

That depends an several things.

What is the layout like, what is the actually necessary resolution at print size, what is the output Color Space, the required file format etc.

If the layout includes Type and graphical elements you may want to consider creating it in Illustrator or Indesign.