Newbie question

I have just purchased my first digicam and wanted to know if I had to take/save the pictures at a particular resolution to print at 7x5" at Boots or the like. Or do they just compress & print the image whatever the size?

thanks in advance.

 

Well this is quite a topic.

Firstly depending on the resolution of your camera you want to take the pictures using the highest quality setting.

Then once you have downloaded them to your PC you want to resize them to the 7"x5" size. However what you also need to do is to adjust the dpi which by default will probably be something like 72dpi. 72dpi isnt good enough for printing photos so you need to increase this to between 240 and 300dpi (magazines use 300dpi but you can easily get away with 240). Now the thing is that when you increase the dpi you reduce the physical size of your photos so what you want to do is to download your photos to your PC, using your photo editing software change the dpi so that it is 300dpi for example, this will reduce the physical size of the print. If it reduces to less than your 7"x5" size then try changing the dpi to 290, 280, 270 etc until its as near to 7x5 as you can get. Once you've reached your optimum dpi/image size then just perform either a simple crop or minor resize to achieve the full 7x5 size. Save this as a TIFF file if boots can print from TIFFS otherwise save as a JPEG using as little compression as you can, burn to CD and hand it to Boots for printing.

HTH

 

Just a point, I saw in Costco that they are doing at 7x5 prints at 16p each.

 

This is not actually correct.

The reason photos show as 72dpi when displayed on a PC is that 72dpi is the resolution of the monitor.

So regardless of using a 1mp camera or a 10mp camera, the photo will still display at 72dpi. The difference of course will be that the 1mp photo will fit on the screen whilst the 10mp photo will be huge in size when you show it a 100%.

Most photo printing services print at 300dpi and will do one of 2 things.

If your photo (when printed at say 7x5) is less than 300dpi, they will enlarge the photo to fit the canvas size (7x5) and your photo will not look great.

If the photo is more than 300dpi then they will reduce the photo to fit but you will not loose any quality.

Many people get screen and print resolution confused and it is not realistic to compare the 2 like for like.

Put simply, you do not need to change the resolution of a photo before you get it printed.

For reference, for a 7x5 photo, a 2mp camera will give you good results (and most new cameras are more than this anyway) and you will only see the difference when you go to bigger sizes.

So onto the maths.

A 2mp camera actually creates images that are 1600 x 1200 pixels per inch.

So if you try and match pixel to pixel, the perfect size print would be 5.3 inches by 4 inches. The move to 7x5 will introduce a slight loss of quality but you will be hard pressed to notice it.

All you need to do is divide the resolution of the picture by 300 to work out the optimum printing size.

But as I said, with most cameras being at least 3mp these days, 7x5 printing should not require you to do anything to the size or resolution of the picture.

 

Wow - what a detailed response. Many thanks. I've just bought a 2MP Canon A60 so hopefully 7x5 prints will look OK.

I understand what you're saying about screen size. If I want to take a picture to use as a PC wallpaper at 1024x768 what quality of image should I use. The ones I have taken at high res are massive.

Thanks again

 

Well you have actually answered your own question.

You will need an image that is at least 1024x768 so seeing that your A60 will give you 1600 x 1200 at maximum resolution, it is more than up to the job.

What you could do it use your imaging software to reduce the resolution down to 1024x768 pixels. Most imaging software will allow you to resize the image using a pixel measurement but using the stretch feature in Windows display settings, Windows can take a larger image and make it fit.

 

i think tou are all going a bit over board all you have to do is
1 Take the card out your camera and take into the shop and they will do prints straight off it 7x5 as long as its more than a 1.5 mil camera.
or
2 if you dont want to leave your card then copy the straight on to cd with out changing any thing.