What is the smallest megapixel digital camera I can use to make a photo like 24X36 enlargement?

Question

I now have an 8 mp camera which allows good enlargement up to 13X19. I often crop a portion of my original photos to make a separate enlargement of just that small portion of the picture. What resolution camera should I be using to get a good enlargement?

Answer 1

You should not search for a better camera.  In your own camera use the maximum resolution setting or try the tiff output mode. You can print this pictures in any resolution you want. The image clarity depends on the lighting nad exposure settings. Photos taken in full daylight will come clean without apparent loss in quality. Becuse the viewing distance is not same for small photgraphs and the big ones. The bigger the photo, you view from a distance.

Answer 2

You can go a lot bigger than 24X36 with an 8Mp file in Photoshop. Ideally you should have shot in Raw and saved as a Tiff, you need all the data that the camera can capture and using Jpeg 'dumps' half of it, here's how.

Open the picture in Photoshop and go to Image>Image Size.

In the dialogue box that appears make th unit Inches and enter the size you want (24X36), this method maintains the aspect ratio of the picture so you may not get both sizes.

Make sure the resample box is checked.

now alter the resolution till you get a file size that equals the formula of 1Mb per inch on the longest size, so in your case alter the resolution till you get a file size of 36Mp or thereabout.

Obviously you are going to have to 'interpolate' the picture to get this size (add pixels) which is not a good thing, this technique ensures you do the minimum 'interpolation' necessary. The formula of 1Mb per 1" on the longest side ensures good quality up to a lot larger than this. I routinely get 6ft X 4ft pictures from an 10Mp camera more than good enough for sale.

With your resized picture open double click the Zoom Tool (magnifying glass icon) which will give you a 100% view, this gives you a view of exactly how your picture will be laid down by the printer.

If you need a print that is exactly 24X36 inches there is another technique.

Go to file New and open a canvas type in 24 X 36 inches and as before set the resolution which gives you a file size of 36Mb as before.

In Bridge highlight your picture and go to File>Place>In Photoshop.

This will open your image on top of your new canvas with a bounding box around it.

Hold down the Shift Key (to maintain the aspect ratio) and drag the corner 'Anchor Points' so the part of your picture you want fills the new canvas. Tap Enter when your happy.

The picture will be on its own layer and you can use the Move Tool to alter where the picture lies. Or you can recall the Transform Tool (Ctrl + T) again to resize.

Finally 'Flatten' the image and save your resized file as a PSD or Tiff, you don't want any compression here. A print house may require as a Jpeg, if so save as Jpeg with the minimum (if any) compression.

In this technique the canvas has determined the resolution and size of your picture again with the minimum of 'interpolation'.

Prints this large really test your lens quality and for best results forget Jpeg, shoot Raw and save as Tiff, and open in 16bit mode.

The print size is determined by the file, not the printer. The printer will just reproduce the file at whatever resolution it is set to (usually 300 dpi).

Chris