Written By: Terry Livesey | www.TerryLivesey.com
Featured Speaker: Terry Livesey
We are pleased to welcome our first featured speaker at Advercado, Terry Livesey. Terry has worked in TV and Film, written books, judges photography competitions, won awards and spends his days creating magic with photography and videography.
We would like to thank Terry for his time. He will take you through everything you need to know about image formats, quality and size.
Image format and image quality – what are they and what is the difference, and more importantly, why should you care?
Okay, so let’s start with the difference: image format is how the image is packaged up so that you can use it in different software, on websites, etc. There are quite a few different formats for different things and we’ll cover those in a bit. Image quality is how well the image is preserved – or not, as the case may be – when you use one of the image formats; some are ‘lossless’ (no degradation from the original), and some compress everything as much as they can so you can send via email or use on websites, but this comes at a cost: if you go to the extremes you WILL notice that your images don’t look quite as good as they should.
Now we have that out of the way, let’s talk about each one and its pros and cons.
Image Format
So we have two types of formats: raster and vector. Raster is a collection of pixels which make up the image. Vector is a file of maths, and people like designers, architects, etc will use this file format for designing things because, as well as a few other benefits, when something is scaled using maths, no quality is lost. Now, as a photographer, I am going to discuss the following formats that relate to the raster principle because this is how pictures are taken.
Okay, so what file formats are the most common for your images?
JPG / JPEG
JPG is probably the most common format, and the most widely accepted, but it is a ‘lossy’ format and as such, as a photographer, I would recommend that this is the format you use once you have finished editing your picture and it’s ready for uploading/distribution. With this format, you have the option to compress the image as much as you want, and personally, I’ve found a sweet spot within Lightroom of exporting at 76% without noticing any change in the final image (Well I’m sure there is, but not to my eye).
GIF
GIF is an old format but is still actually used today. For photographers, the problem with GIF is that it will only display 256 colours, so it’s really not suitable for your beautifully colour-rich photographs. But there is one advantage to a GIF, and that is that you can have several frames in it and basically create a little animation. And because it only stores 256 colours, the file size is low, so it can be embedded in emails and websites for your viewers to enjoy; so yes it still does have a place in this modern world.
PNG
PNG files will allow you to save your files in a lossless or lossy format, but the main reason for using PNG is the fact that you can have a transparent element to your image. It’s a great file format for graphic designers as it allows them to build things with transparent sections for websites or brochures. As a photographer, I wouldn’t recommend using this format unless you are cutting out the background to make it have a transparent section.
TIFF
TIFF files are great for photographers as they are lossless, and will also remember all of the data if you converted your file from RAW, so you can bring the shadow and highlight detail back from the original image that your camera took. It also allows you to create layers to your image so you can edit different sections on different layers and come back later to manipulate them again. Professional photo editing packages make use of TIFF as standard. This is a file format that you would use as your master and then export to JPEG/PNG for the version you use on websites, email etc.
The file size limit of a TIFF is around 4Gb, which is pretty large, but I have done projects which have exceeded this and have had to change formats or reduce the size by combining layers.
PSD/PSB
This format is a propriety Photoshop format. PSD is the standard one, which is very similar to TIFF but not quite as compatible with other software. The PSB version allows you to save files bigger than 4GB, and Photoshop will automatically ask you to convert to it if you hit the file size limit on your current project. As I use Adobe software I personally use PSD file format for most of my images, if I’m editing them in a little bit more detail than is available in Lightroom or I’m creating a flyer, poster, etc.
NEF/CR2/RAW
This format is the one that comes out of your camera if you have the option set and will usually come with a smaller JPG as well, to help your software display the image (or for several other reasons which I won’t go into here).
The one thing about RAW is that it captures everything your camera can see. This is actually more than your eye can see, which means you have extra data to play with and manipulate. The other thing is that the image will be flat rather than as you see it and this is so it can capture all the extra detail and let you make the image look the way you want it to. RAW files are meant to be processed before you show off the image. A RAW file is also not editable – you will need to load your RAW file into your editing software and then save it as another file format: PSD/TIFF/JPG/PNG, etc. with only PSD and TIFF keeping all the extra information that is in the RAW file for you to manipulate again and again.
Now there are other formats but, as photographers, these are the main ones you need to know about.
Image Quality
Image quality should be decided for your output files only; that’s the ones that you will upload to websites, send in emails, upload to Instagram etc. For your master, you should always use a lossless file format like TIFF or PSD.
So why does this matter? Well, if you save an image as JPEG and then go and edit it and save it again, you are effectively compressing an already compressed file which will lower the quality, and if you do this several times, you will eventually have a picture which looks hardly like the original. There are plenty of videos on Youtube where people have done this to prove a point, so I won’t waste my time here by repeating them. Now, if you save an image as a JPEG and then put it into a watermark program (because, as photographers, we like to watermark our images), then you will probably be alright and not notice any difference; the point is not to use it as a master file.
Why alter the image quality? Well, it actually reduces the file size, which can be really important when uploading to websites, email, etc, as a webpage which is slow to load will put off your prospective viewer, and they might just give up and go somewhere else.
So when saving a JPEG for the end result, I quite often save at 76% unless I’m going to be adding a watermark etc, then I save at 100% and compress down to 76% on the watermark software. So where did I come up with 76%? Trial and error. Well, okay, a couple of hours saving at nearly every percentage to see what the difference was, and this one seems to be the one for which I couldn’t see any difference! You try it for yourself and see what you think.
Image Size
Whatever your original file image size is, (that’s the dimensions of the horizontal and vertical i.e. 1024×768), I would recommend only reducing it on the final output version that you do, i.e. JPG. Keep your original / master in the largest size possible otherwise, when you come to print, you might find there is not enough detail for your image to look its best.
So why reduce the size at all? Well, first off is the fact that reducing the file size will help with loading and transmission; secondly, if you have an image of 8000×6000 pixels, but the views screen is only 1400×1000, then the image is going to be too big for the page, and people are either going to have to scroll left and right, up and down to see the whole image, or the web software is going to reduce the file to a size which fits and that software will not be as sophisticated as your editing software and will most likely reduce the quality of the image the viewer gets to see – it will also take up more space on the website, and you normally get charged for space or have a limit.
So what sizes should you use? Well, there is no real set figure here, but there are personal recommendations and guidelines from various platforms like Instagram etc (but they will downscale your images for you if needed).
Personal recommendations or suggested sizes:
Email: 1024×768
Website: 1024x 768 or 2048×1024 (if the image will be displayed larger or if you want the viewer to see a bigger image when they click the photo)
Instagram: 1080×1080(Square), 1080×566(Landscape), 1080×1350 (Portrait)
Facebook: 1080×1080(Square), 1200×630(Landscape), 1200×1800 (Portrait), 820×360 (Cover photo)
TikTok: 1080×1920
LinkedIn: 1200×1200(Square), 1200×628(Landscape), 1080×1350 (Portrait), 1128×191 (Cover photo)
Print: Original resolution
Please note that a raster file, unlike a vector, cannot be upscaled (made larger) without losing quality as the information is not physically there and the computer has to guess, and to be fair there are some amazing packages out there which do a great job.
Round Up
So all of this should at least help you in making the decision on the optimum file type, compression setting, and final output size to use.
Written By: Terry Livesey | www.TerryLivesey.com
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