I am a novice when it comes to photography. But I have a picture that I would love to submit to a photo comp. Their specifications are: have suitable resolution to be printed between 596mm x 422mm (A2) and 841mm (w) x 1189mm (h) (A0) I tried to increase the resolution on photoshop and ended up with these numbers: Image size 1.84 M - With 644 pixels - height 1000 pixels - resolution 300 pixel an inch

Could any let me know if these dimensions are acceptable?

  • What is the original size of your image ?
    – Olivier
    Aug 21 '15 at 7:58

No mette. You are doing it it wrong Xo)

1) You already have a photo. DO NOT MANIPULATE IT! If it works, it works, if not...

2) Ok. What are the dimensions of your original photo?

3) @ths already gave you some recomendations. Sumarize here:

For an A2 (42.0 x 59.4 cm) (16.53 x 23.38 inch) print:

100 ppi 1653 x 2338 px. (4 Mpx photo, Just enough quality)

150 ppi 2479 x 3507 px. (8.5 Mpx, Good quality)

200 ppi 3306 x 4676 px. (15.5 Mpx, ideal quality)

A0 (84.1 x 118.9 cm) (33.11 x 46.81 inch) print:

50 ppi 1655 x 2340 px. (4 Mpx photo, Not suitable)

75 ppi 2483 x 3510 px. (8.5 Mpx, Just enough quality)

100 ppi 3311 x 4681 px. (16 Mpx, Good quality)

A note:

In my opinion the specifications are really dumb. They should just say:

A Photo of 6 Megapixels (or whatever) or more.


As print size increases, the required resolution decreases, since the typical viewing distance gets greater, too. For A2, a resolution of 100dpi may be acceptable (the chart here recommends double that, though), for A0, 50dpi, which means a pixel size of 2346x1661, at minimum.

That said, if your original photo is smaller than that, no amount of resizing in PS will produce better print quality! You may fulfill the letter of the law, but the image will still look very soft and lacking detail.

I'm amazed where you got a 1000x644 photo from anyway, no camera from this side of 2000 produces that (0.6MP), maybe you accidently reduced the original?

Do not fiddle with the DPI settings in PS, this number is quite useless and only informative. Only the actual pixel size is relevant. (Well, you can put in desired dimensions in mm and dpi, which calculates pixel size for you)

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