Sometimes when you view a photograph for the first time, your first thought is "wow." You may feel a surge of emotion. The image might make you feel sad or happy or sweet--it may even make you feel angry or upset in some way. The important thing to remember is that there are no right or wrong emotions, no one thing you absolutely should be experiencing when looking at a photograph. The photographer may have intended you to feel a certain way, but if you don't feel that way, it is neither the fault of the photographer or the fault of yourself. You either feel something or you don't. Whatever the case may be, it is certainly true that first impressions matter. Whenever you're critiquing a photograph, the very first thing that you should mention is what your first impressions are of that image. How do you feel when you look at it? And perhaps more importantly, what do you immediately like and dislike about that image?
surpresas no meu jardim (inclui uma foto da tentativa) by Flickr user Ana_Cotta
The answer to this question may come in different forms. It could be that you just don't like the light--if that's true, then say so. But it could be that the emotions you feel just don't sit right with you. If that's true, it's not necessarily a comment on the quality of the image, but rather on the emotions that the image makes you in particular feel. Learn how to recognize the reasons why you might have a certain reaction to an image, and either leave those comments out of the critique altogether or express them in a way that lets the photographer know that your reaction is not necessarily going to be the same reaction everyone has.
Always try to find something you like, to express first. Think about how good the photo is at showing action, how well-composed it is, and think about things like color, or whether or not the photographer was able to capture the personality of the person or animal featured in the photograph. There's always going to be something to like in any image, whether it's just the sense of the moment that's being captured or if it's the technical perfection of the image. And you must always follow any expression of what you like with the reason why you like it. Just saying that you like something doesn't actually help the photographer all that much — but if you tell her that you like a certain element because of the way it's lit, or because of the way that the shadows bring out detail, or because of the complementary colors, you're going to give the photographer a good sense of what it is that she did right when she shot the photo.
From there move on to what you don't like about the image. It could be just the overall emotional sense that you get from it, but it could be something much more easy to articulate such as a static composition, a technical error such as mis-focusing or motion blur, or just a subject that isn't that compelling. Remember you also need to have a "why" when talking about the elements that you don't like — in fact it's probably more important for the things you dislike than it is for the things you like, because it gives the photographer a reason for the failure of that particular photograph, if there is one.
For example, don't just say "your image is motion blurred," say, "your image has some motion blur in it and I don't think it works for this particular scene because the motion of the subject isn't as important as the clarity of what he or she is doing." For example, a snowboarder leaping into the air who is motion blurred is probably not going to be as compelling as one who's been frozen in mid air, surrounded by flying snow. We need to be able to see things like the action of the snow and the expression on the snowboarders face in order to really have an emotional response to that image. Again, it's important to articulate the reasons why something works as much as it is to articulate the fact that something doesn't work. Make sure you keep personal biases in check—for example, if you really just don't like black and white images you need to try and discard that opinion at least for the time being, and criticize the photo from the perspective of someone who does like black and white images. And it's always helpful to make sure you disclose those biases before you critique--just say, "I don't usually like black and white images," and that way the recipient of your criticism will be able to take that bias into account when thinking about what you're saying.
A critique should always include positive comments, even if deep down inside you don't really believe there's much that's positive about the image. You can always find something, as I said, if you look hard enough. But don't think that the opposite is true—you don't need to necessarily find something negative in every photograph you're critiquing. It's okay to say that an image is perfect—if you start criticizing things that don't really deserve criticism, you're going to be looked at as nitpicking, and unwilling to give praise where it's due. And if that's the sort of reputation that you develop as a critiquer, people aren't really going to look to you for advice. In fact people may go out of the way to avoid getting critiques from you, and they may also discredit the critiques you do give, even if they're perfectly valid criticisms.
Most importantly of all, you should always aim to be as polite and kind as possible. It's never a good idea to be rude or to take on an air of superiority when talking about somebody else's work. Don't make fun of someone's work, but always make sure you're honest. Don't over praise if the photograph isn't worth over praising, because that isn't going to help a photographer who really needs the help.
It is important to remember that you are just one of the many people who could be viewing that photographer's work, and not everybody is going to have the same impressions that you do. Lots of criticisms are completely subjective. Most of the time composition, emotional content, and subject are going to be viewed through the lens of experience of whomever happens to be making that criticism, yourself included. For that reason it's necessary to be able to identify when something is objective and when it is subjective. In other words, if it's a comment you have about the photo that may broadly differ from the comments someone else has about the photo, make sure you point that out. For example, you may say that the subject would look better if shot from a lower angle with a shallower depth of field. Some other person, however, may think that the perspective creates a different emotional mood, and that a broader depth of field is needed to give the image some context. If it is a comment that may differ according to viewer, just to make sure that you let your subject know that your opinion is a subjective one. That way, he or she can evaluate what you have said, decide whether or not it applies to his overall vision for the image and then choose to accept or reject the criticism based on that.
It's true what they say—first impressions really can be everything, which is why it's important to think about what your gut reaction was when you first saw the image, and then try to communicate that to the person who is asking you for advice. Your opinion about a photograph may change as you look at the details, and if that's true make sure you communicate that change in opinion as well as your initial gut reaction. Sometimes, gut reaction matters more, because it is what makes a viewer stop and take notice of an image. The gut reaction is what makes you decide whether or not you are going to look at the details, so ultimately it is the most important part of the critique.