Ive talked before on scanning for photo restoration but I still cant believe what I am seeing out there on the web.
Photo restoration is an exact science but it can only be achieved if the original image is created as a digital file. This file must be of a certain size in order for the restoration to be made. Digital images are made up of pixels, single points of light and colour in varying intensities. If there are not enough of them the photo restoration cannot be made.
To create a file with enough data photos are usually scanned to a computer. So many restoration websites ask customers to scan their photos at 300 dpi. This means there will be 300 of those tiny pixels per inch. What if that photo was only an inch square? Then it would only have 300 pixels by 300 to restore with. You would probably want that image enlarging wouldn’t you? Alas it wouldn’t be possible with scan of 300 DPI, I’ll explain.
To an ordinary person who knows nothing about the digital world this may sound like techno speak but what it means is that your image is effectively like a roman mosaic. If there is a crack through the images and it has a stain or tear, trying to restore this would be impossible. There are simply not enough mosaic tiles to move around to fill in and patch up the photo.
If the number of pixels in increased for this little 1 inch photo to say 2400 DPI or 2400 pixels along the photos edge this would mean not only would be millions of little squares to restore but it also could be printed in a variety of sizes.
Photo Restoration and scanning at 300DPI. This image show a 1 inch image scanned at 300 DPI and then at 2400 DPI with inches measured across for size comparison.
Requesting a scan for a photo restoration from a customer without even asking what they require in terms of restoration size is extremely presumptuous. You simply cannot set this scanning figure in stone like so many of the photo restoration services do. It’s very much like building a house without first working out how many people are going to be living in it. You wouldn’t build a 2 bedroom terraced house for a family of 12, would you?
300DPI would be fine for large images such as those of 7×5 inches or above but again it cannot be assumed the final image is to be the same size when restored. I’ve found that most people want their old images enlarged so they can see more or display them with pride.
Can you lighten my pictures I’ve scanned at 300 dpi?? We haven’t even talked about grain and shadow detail either. If said small image was scanned at 300dpi and the request was for “lighten” and “enhance” the detail the image would end up looking like a bunch of pebbles on a beach. The more pixels you have in the scan will enable the shadow areas to be probed and lightened, to squeeze as much shadow detail out as possible without those little pixels showing through as noise or grain.
To summarize, requesting a scan of 300DPI for a 1 inch image means it can be printed at one inch, what if you wanted it 10 inches square? The correct question to ask a customer would be “tell us what size you would like the photo to be and well tell you what setting to scan it at”. Assumptions in photo restoration will get you nowhere, just into hot water when it comes to providing what the customer wants. Always ask and advise, don’t assume when it comes to photo restoration. For more on this topic visit saving your file correctly for photo restoration.
Hi Richard, there is the DropBox or Yousendit services or even an upload page on your site, but once again for a lot of people this is another technological hurdle they have to overcome. This kind of file sending does overcome the 10Mb Gateway issue though, but try explaining that to some of the folks we deal with on a daily basis where posting is sometimes complicated. Forgetting to put name and address on the back or even including any correspondence at all!
Tim, I have to agree with Neil that the customer is often not as computer literate as we would like them to be. Also I must point out another restriction that can be limiting to your theory of ‘scan at the highest resolution’ the email gateway for many people can be only 10mb depending on the company. This restricts the file size that can be sent for restoration.
“300dpi” arises solely from the ballpoint figure that 300ppi might make a photo good enough for fine-art quality at usual viewing distances and sizes (say 8×10″ at arm’s length). The confusion you mention comes from the double misunderstanding that an output resolution-control parameter applies as an input parameter. Obviously it doesn’t; the correct instruction, in all cases, is to have people scan at the highest resolution their scanner can manage. It doesn’t really matter if the scanner isn’t up to it – as long as it doesn’t go too far into interpolation, you can downsize to find the optimum sharpness as long as you have some data.
The trouble with any “technical” issue in my industry is explaining anything like this even in the simplest of terms. More often than not it gets a response of “its all gobble gook to me”. This a response from one of the main age groups of people who look for my services, those who are aging in life and who are interested in preserving their family tree but do not always have a good understanding of computers or wish to understand past sending an email or surfing the net.