Many people how to get their images prepared for Alamy, especially their request for 48mb images. It is a bit confusing, so here is my method using Photoshop – but if you use Elements or some other software it may help you too.
The file you upload doesn’t have to be 48MB in itself – but has to be able to be converted by their customer to a 48mb TIFF.
This means you have to upscale the size of the file yourself before sending it as a jpeg.
To do this – Make sure you shoot in RAW (although jpeg, may work – it’s just I always shoot in RAW) and work on the image in Photoshop in 16 bit colour (which you will be automatically if you have opened the RAW file in Photoshop via Lightroom or Canon Camera RAW software) , cloning out dust, tweaking the levels etc (For stock libraries, don’t saturate the colours or do any sharpening – they want their customers to be able to do this to their own tastes/needs).
Then, when all is done, click the Image menu and select Image Size
In that dialog box make sure all three tick boxes are ticked and that ‘Bicubic Smoother’ is selected in the drop down box. Set the resolution to 300 pixels per inch (240 pixels minimum)
In the top width and height windows make the longest edge (depending on if the image is portrait or landscape orientation) around 5000 pixels – you will need to play with this figure to get the right length for your camera – the aim is to get the pixels dimensions figure at the top of the box to 96mb or above – but get as close to 96mb – as the higher you go the more chance there is of the quality deteriorating. Click okay.
Now click the Image menu again – select mode and select 8 bits
This will halve the file size (from 96mb to the magic 48mb). Now save in the normal way as the highest quality jpeg. The jpeg will vary in size depending on the type of image, how many colours in it etc and could be 8mb up to 16mb or more – but probably never above 20mb. The important thing is Alamy can now convert it back to a 96mb TIFF or PSD file for their customer.
I hope this demistifies the process for you?
And I haven’t forgotten I said I would do a tutorial on adding titles to your borders in Photoshop – it’s just this question came up from one of my students and as I had written it all down for him, I thought you could use it too.
Just a quick note that since May 2010, there’s no need to interpolate (at least not above 24mb): http://www.alamy.com/Blog/contributor/archive/2011/07/01/4876.aspx