A most compelling evening (well if you are a camera club member) had courtesy of Keynsham Photographic Centre. Simon and Neil took us through papers, sizes and types of processes KPC offer and their knowledge and enthusiasm went a long way to explaining why KPC is a destination of choice of so many serious photographers here-abouts. Around 2 in 3 of those present were already users but we all had something new to learn about the services they offer, which are quite extensive. I have always found them to be helpful and friendly and I am happy to pass on a recommendation to use them.
Why print? There is an emotional and a logical answer to this. The emotional one is that we do seem to react differently to a print than to a projected image or one on a phone or other screen. This is certainly the case with the written word. With pictures it might be an age thing, with those of us of a certain maturity having an emotional tie to what we started with, the family albums and so on, but as these are family history it is not uncertain that these emotions are passed on. It might be the way we view what is art. Even slides are, these days, often rendered digital. Prints have a longevity that digital files cannot match.
The logical one is more existential. Our photographs aren’t photographs until they are printed. They are computer files that are capable of being rendered as images given the right, seldom very cheap, equipment. To that extent they are, at best, semi permanent records. They exist not as pictures but as 1’s and 0’s and that makes them vulnerable to damage, loss and redundancy in many different ways.
One of the questions that came up in discussions was the notion of the minimum resolution (pixels per inch or PPI) as a ratio to print size that is compatible with a reasonable quality print. In order to look at this we need to look at and differentiate between two measurements that the computer file we turn into a picture holds – and which can be reset via (photo editing) software. The first is Pixels Per Inch and the second is Dots Per Inch, or as we will refer to them PPI and DPI.
There is a previous post dedicated to this and a good start if your interest is more than passing. Essentially the PPI is a measure of the resolution of the computer file when shown on a screen and the DPI a measure of the resolution that a printer will reproduce the computer file as a digital print. They are not the same thing, they are not interchangeable, the connection between them is that you cannot use DPI to overcome low resolution in the PPI. That might not seem like much of a connection but it is a common error, at least it is a common misunderstanding.
Just as one is not strictly reliant on another there is an optimum setting for both, but it is not a single magic number or formula. This is because different manufacturers of camera sensors and printers construct their wares in slightly different ways to slightly different priorities. The only rock solid constant you can apply is garbage in garbage out aka GIGO. What doesn’t help is that there are always going to be subjective elements to the ideas of output and acceptable, but we can set these aside.
A slight diversion, but one that is worth taking, is the purpose for which we are taking our images in the first place. The digital age has brought with it a number of outlets that, even 20 years ago, were pipedreams or even unimaginable to most photographers. Film cameras would enjoy their predominance for another 10 years in the “serious” and professional markets. A decent living could still be made from stock photography. These days there are far more outlets and they demand different things of the data files they publish. What remains is the fact that proper prior planning prevents poor photography. Start with the end in mind and choose formats etc accordingly.
The argument for recording images in camera RAW is that all the information is left in. The argument for JPEG is its universality and space saving compression. The fact is you can shoot in both and convert your final image from RAW to JPEG or any other format (has to be some other format as you cannot save in RAW). In your final version of the image is the information that other devices are going to use to present your image, including colour space, PPI and a whole lot else. The point here is that you are going to have to make, or let programme defaults make, these decisions to determine the look of your output (as best you can).
So, long way round to the answer we were looking for but the fact remains, that for all the reasons above, there simply is no answer to the question of a ratio of file resolution to print size because Pixels are not the same size on all cameras – 24 mega pixels on a 35mm sized sensor take up more space than 24 mega pixels on an APSC sensor. There are approximations, guidelines and above all, experience. Let’s look at rules of thumb, but first a caveat.
Pixel peaking, the urge to zoom to the maximum and suck the teeth at the lack of relative clarity, is neither helpful nor useful, outside of certain photographic publications desperate for some comparators in a world where you really have to go some to find a “bad” lens or sensor. It’s the aggregate of the pixels used that we view and a badly composed photograph is a badly composed photograph regardless of the amount of money you have spent or your equipment’s DXO rating. We are here looking at making a print of what you have got, regardless of your motive to print it.
Lets first talk of PPI. Smaller sized prints, say up to 10 x 8 (ish) we can get a reasonable print at 125 ppi. That is to say at arm’s length it’s going to look OK. Press your nose against it or use a magnifying glass it is going to look pretty rubbish. I have to say that such a view point rather spoils the whole point as, again you are looking at the aggregate of the pixels after all, or as I like to call it, “The picture”. This is a fall-back position only, If your default is 72ppi (i.e. it’s designed to show up on your computer or phone screen) then you are not going to get much above a 6 x 4, maybe 7 x 5 at a pinch, out of it (feel free to prove me wrong because you are only going to find out by using your combination of equipment and the printer you choose). The best lies between 200 and 300 ppi, by more or less common agreement. KPC ask for 305 PPI. Basically of you use the 300 end of the range you are likely to be close to the optimum for most commercial printers at standard sizes. Refer to your supplier for the necessary information. To change images PPI we use editing software like Lightroom, Gimp or Affinity.
But we were looking for a rule of thumb. Any minimum figure is a result of the combination of equipment particulars and specifications and materials used.
So, take the longest edge of the image (measured in pixels) and divide by the longest edge of the desired print size (measured in inches). If an image measures 3,840 x 5,760 pixels and you want an 8 x 10 inch print. 5,760 pixels ÷ 10 inches = 576 ppi. That’s more than enough resolution. If you want make a 30 x 20 inch poster out of that image, you’d have a resolution of 192 ppi (5,760 ÷ 30), which isn’t high enough for optimum, if we are looking at least at 200 PPI. This is a minimum remember, so adjust accordingly.
Alternatively, and my personal method, size the image in inches at a ratio of 1:1. So an 18 x 12 print is sized as an 18 x 12 image in my editing software (Gimp). The resolution is set at 305 by 305 dots per inch as I use KPC, and the image, in pixels, is 5490 x 4118. The down side is the file size, the upside is its going to fit without faffing around.
So http://www.keynshamphoto.co.uk/ and start printing!
I have spent some of your generously donated time over the last several posts talking about the appreciation of an image and in trying to encourage wider participation in competitions. Talking to other people in some other photographic clubs and indeed, some remarks Peter Wheeler made in one of his visits to us this season, there broadly seem to be two focuses: the competition focused clubs and the participation focussed clubs. These are not two mutually exclusive categories, sensibly there cannot be one without the other, but it is the way that the mix of the two is dealt with that determines the nature of the club. BPS, for instance, appear have a set of images that they use for the many competitions that they enter and they are a very successful club. Dorchester appear similarly disposed, and these were the top 2 clubs in the WCPF 2013 competition. We are more participation focussed and either way there would be no club if it were not for its committee. From and on behalf of the floor, thank you. Last Thursday we had our AGM, which had a reasonable turnout by any club standards that I have been to on whatever topic (not a huge number I will admit). There was: discussion of important topics to the club; consumption of tea, coffee and biscuits; reportage on the path of the club; efforts were lauded and decisions arrived at democratically. Overall, I would judge it as a success because people got involved.
Ruth, Mark O and Dan E were voted onto the committee in the posts of Club, Competitions and Events Secretary’s replacing Julie, Ian and Hanneke at the end of the season. A great deal of thanks is owed to the outgoing members for their considerable parts in making this a successful club and thanks due to those incoming for the prospect of its continuation.
The topic on which we were most exercised was that of the competitions, specifically the format and most particularly the lack of and diminishing numbers of prints being entered. Firstly I will hold my hand up and, as a distinctly novice member, admit I have not entered any physical prints in any of the competition rounds this year. Indeed John P. has been the only consistent entrant in this category and thanks to you John, because the novice print category is an issue not a dead letter. There is a decision for the committee to make about whether the novice category continues into next season for reasons I have blogged about previously, but, in essence, boils down to the fact that the border between the two has become increasingly blurred. There is a but and a very important but so worth flagging: this may become a self-fulfilling prophecy i.e. those who enter are benefitting from the feedback and those who are discouraged by the perceived gap between their own and others efforts remain so and do not enter. The reasons were discussed why this is so, the general lack of prints, and reasons included “Faff” (a general term for producing something the individual thinks not worth the effort as measured by the return), time, space, and additional cost – travel (time cost) being the chief issue when using Keynsham Photographic (KPC). As Mark S. pointed out, as part of a different point but one that applies in general, you can’t eliminate the category and still compete – i.e. digital projection only. Yes I know Zen Photo is web based, but they meet physically four times a year and they compete as a club.
Competing is a core value of our club, but it is not the reason for it, in my far from humble opinion, participation is its life-blood but we have an imbalance at the moment that needs to be addressed and that is getting more people involved in competitions in general and in prints in particular. It is getting you involved in competitions in general and in prints in particular. Yes, next season I will be entering the print competition regularly, a little late for New Year resolutions I will admit, but then they are hardly worth making the effort over if you have no intention of keeping them. I have every intention of keeping this one (and only). The ease and relative speed of entering the projected is not in dispute, but the experience of producing and mounting a print is far more tactile and gives a different perspective as Mark O. attested.
So, 10 questions to ask and my own answers (in brackets). The only permissible answers are Yes or No because anything else is a No, all dressed up with nowhere to go:
- Did I join Reflex CC to become a better photographer? (Yes).
- Is entering the club competitions a positive part of this? (Yes).
- Have I learned anything by looking at the entries and listening to the feedback? (Yes).
- Am I looking at photographing subjects differently than before I did this? (Yes).
- Does that effect the way I take photographs? (Yes).
- Has the overall effect of the feedback been positive? (Yes).
- Is there room for improvement? (Yes!).
- Would entering my own efforts personalise the feedback? (Yes).
- Have I made the best of the opportunities the competitions have presented? (No).
- Does a lack of trophies mean I am no better for the competition process? (No).
If anyone of the first 8 is a yes, then there is a personal gain to be had from you entering the competitions. Logically, enter. Logically enter both projected and print. As for the self imposed quality issue then I would point you to the observation that, even in the Olympic 100 meter sprint final, every athlete is not running against the other athletes because they cannot maximise their own performance against them and run their own race. The things that they can control are the things that are in their own race i.e. they are all running against themselves and their own limitations. Same for us in club competitions. And you don’t have to be a “photographer” to contribute to photography, anymore than you need to be a writer to contribute to the essay form. You just need to plan, do and review to get better.
There are a number of questions that might arise surrounding prints, and the first one is, “What size file does it take to make a good photographic print?”. For Reflex CC competitions the mounting card dimensions are exactly 50 x 40 centimetres (roughly 20″ x 16″) and the image can be any size up to that. The decision is yours. The competition form has to be filled in as with a projected image + a digital copy of the image also has to be submitted. This latter part helps with the blog when publishing results and the catalogue I have done with the last couple of rounds and will continue to do as long as its viable. Rather pointless having an empty space where a winning entry should be. So back to the size of the file. If you have bought a digital camera in, roughly, the last 10 years, you should be OK. KPC say that the jpegs they use are to be 305 PPI (pixels per inch) and you can do this through image scaling software (Photoshop will do it, ditto Paint.Net so will GIMP)
Part of the problem I have with the print section of the competition, I admit, is that it is more difficult to see and remember what is which when it comes to the feedback. The big, vibrant projected image is a different experience to the more tactile, focussed print. I sit at the back of the room, I know, but that is so I can use the light to write my notes. This rather puts me at a disadvantage as compared to the projected images, given that the optimum viewing distance is usually given as a 1.5 or 2 x multiple of the diagonal of an image – making a 16 x 12’s prints optimum between 30 and 40 inches (76 to 101 centimetres), though time can be spent walking around, looking at the prints close up. Therein lies a very important point. The relationship between the viewer and the image is different in a print than it is in a projected image, we react differently to it. It isn’t just a question about which is better, because the answer depends upon the context you are viewing it in. The photo-marathon was as much about moving around for the viewing as it was in the taking. The Interaction was different. Broaden your experience and double your chances of constructive feedback by entering both parts of the competition next season and keep practicing by entering the Flickr competition until then. Maybe we need a Flickr evening?
As an evening a very successful AGM. This is a vibrant and happy club to belong to, made so by its members. Yes we need to expand our competition base but that is something we can all contribute to. I look forward to the rest of the year.
NEXT MEETING – Practical, bring your camera and as it is product shot time, feel free to bring a tripod if you have one and anything interesting you want to photograph. Very successful last time, you will probably have some competition entries among these!