Last meeting was the territory of club member and treasurer Steve Hallam, talking through some of his digital history. Steve is an Olympus fan and has been for over ten years. Micro four thirds, the name come from the diameter of the sensor in inches, is the invention of Olympus and as Steve pointed out, the first system to be designed exclusively for digital from scratch. The first Olympus Steve owned had a 5 MP sensor , which when compacts these days can pack 20 Mega Pixels, sounds restrictive. In reality most people would be largely untroubled by 5MP sensors, the key being the quality of rendition not the size. More Mega Pixels give you more room to crop and still get a reasonable image. The ability to resolve reasonably accurate colours and the capacity to restrict noise at higher ISO’s are generally bigger factors in most peoples’ photography . The bigger numbers in terms of Mega Pixels are something driven more by perceived marketing needs (bigger must be better) than actual customer requirements.
For so long full frame, as Steve pointed out a tag rather than a technical term of any enlightening feature. The 35mm (actually 36 mm but that is a spurious accuracy) was of course the film size in most SLR’s and has carried over to the digital age as the most common “professional” size. I will come back to the need for the inverted comma’s shortly. In the film age, especially from the late 60’s onwards, 35mm was pretty much everywhere. Unless you were doing advertising or studio work then the frame size went up to 6 x 4.5, 4 x 5, 10 x 8 and so on. Hasselblads used 120 roll film (6 x 7 cm). Just like the Box Brownie. Only there was a bit of difference price wise. Also, it has to be said, there is a slight difference in quality too.
The reason for the inverted commas around professional above is that there is no such thing as a camera by which one becomes a professional by being in possession of. There is plenty to be said for the idea of a larger sensor – and some people bang on endlessly about it – but, as been said before in this blog, unless it is predicated on an actual photographic need then there is no reason why a professional has to shoot with a 35mm sensor. Damien Lovegrove doesn’t, as he explained when he visited us back in July 2014, he uses APS-C (among other formats I am sure). Any argument based on the logic of sensor size would have that a 6 x 4.5 medium sensor format has to better than a 35mm and so on. The question always has to be “At what”?
Lugging a D800 across Antarctica to photograph polar bears in the wild may seem like hard work, it is, after all a sizeable chunk of Bakelite in its own right. Adding in the heavy duty lenses adds even more bulk and that’s before you realise the nearest wild polar bear is 12,500 miles to the north (it pays to do your research). You had better have a really, really good reason for packing it in the first place. Well that would be weather sealing, shock-proofing, reliability given that it’s 2,500 miles to the nearest camera shop to replace that broken lens (assuming both that you are going North and turning left(ish) and Punta Arenas has a camera shop, otherwise it’s 3,700 miles in a completely different direction to Auckland). You may require very large blow ups at a high dots per inch count, there are any number of reasons you need a full frame camera, but , logically, not one of them is because you are a professional. Steve pointed out the main advantage of the Micro 4/3rds format is the capacity to build smaller, lighter cameras.
Smaller lighter cameras with smaller sensors, yet we still think of lenses in 35mm equivalent terms and that does make things easier for comparison reasons, but allows for some confusion. When we talk of crop sensors we are talking about the size of sensors relative to 35mm and as most sensors are smaller than this then we are seeing a smaller image given the same focal length of lens.
A confusion creeps in with the idea of “magnification” which a lot of people assume to be a telephoto effect because a 100 mm lens on a 35mm camera shows the same as a 150 mm lens on an APS-C or a 200 mm lens on a micro 4/3rds and the logic goes (off at a tangent but it’s easy to see why) a 200 mm pulls in the image twice as much as a 100 mm lens. Well when you double the focal length on the same size sensor it does, the mistake is to not factor in the change in the size of the sensor. If an image is made with the same lens, but a smaller sensor, it shows a smaller area. Enlarge both your 35 mm and you crop sensor images to, say, 10 x 8 inch print and the degree of enlargement, the magnification if you will, will be greater for the smaller sensor than for a larger one. Hence you might get an inkling of why more Mega Pixels on this year’s sensor than last sounds attractive – you can make larger prints without a loss in quality. Well sort of, as, after a point, those extra pixels start to get in each other’s way.
So, our thanks to Steve for bringing up some interesting topics and for sharing his images with us. Much appreciated.
N E X T W E E K
NOT AT THE CLUB. Light trails, meet at the fountains on the centre. Bring cameras and tripods we are going to be taking some light trails. 7.30 commencement.