Scanning resolution and Jpegs

The one thing that customers phone up and want to talk about is resolution and what does it mean. It may seem a bit teckhy but it is really fairly simple.You want a good resolution so 4000 dpi for slides and at least 800 dpi for family photos, saved to usb – there easy …. now the bit more wordy version –

  1. The ‘dpi’.  Generally speaking the higher the dpi – dots per inch –  the greater the clarity or resolution. We offer 4000 dpi for our slide and 35mm negative scans and this provides pretty good results. There are scanners out there that claim to give higher resolution, I have one that can scan at 9600 dpi, but for me 4000 dpi is the benchmark with a good clear pixel size and fast computer handling. With photographs which are usually bigger, for example 6 x 4, 7 x 5, A4 etc, we reduce the resolution so that the file size does not become unmanageable. Generally we scan at 1200 dpi or 800 dpi but on request we have scanned at higher resolutions. (one project for a conservation group used file sizes of 180 mb, oh my computer did suffer!)
  2. The ‘jpeg’ image. Jpeg images are cleverly compressed pictures which provide excellent resolution but with a smaller file size. These images compare well with uncompressed fomats like TIFF or RAW but at less than a tenth of the size. Results with a 35mm slide saved as 95% jpeg  at 4000 dpi give a file size of about 3-5 megabytes and on a modern tv are outstanding – pixelation, blockiness, is almost eliminated. We do not compress any more except on request when thumbnails or small images may be required.
  3. USB sticks or external hard drives. We prefer to place the files on usb stick mostly these days, I think the days of optical discs are numbered!  Usb sticks can be used on most smart tvs and of course on your computers. When you receive your stick or drive you should back it up to your computer hard drive straight away. I use three different locations for my backups.

I hope this short article helps you when you are deciding on your scanning provider. Obviously we want you to use us but there are some good competitors out there and we feel we stand up well against them. Most of our work is from returning customers a fact I am very proud of!

David.     January 2018.  Saturn Films 1969  Cwmgwrach, South Wales.

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