What's Acceptable?

What's Acceptable?

There's no camera or lens that's perfect, though some may come close. There's always a compromise somewhere. I'll look at a few areas of performance where you need to make that judgement call.

Le's start with sensor noise at high ISO, it's as good a place as any. In their infancy, digital cameras produced noisy images at ISO 400 and above. Bear in mind though, that as the film era had reached its pinnacle grain was evident in emulsions of ISO 400 and above. The latest Fujichrome 400 Professional had well controlled grain and much finer than older types. Grain, and noise, were accepted as part of the image whichever medium you shot. News pictures, often taken in less than ideal conditions necessitated high ISOs and grain and noise were part of the experience. Just think of some of the classic news shots of the past. Lets also not forget concert and sports photography in low available light venues. Back in the day there were those that wouldn't touch ISO 400, so they missed out on photo opportunities.



ISO 6400 with indoor action


Today, ISO 1600 is effectively noise free and indeed ISO 12800 is usable on many models. Sure, if you pixel peep you may see some and camera reviewers tend to do that, but in practice how much are you going to notice between the different models and brands. Even cameras from a few years ago aren't that bad, certainly when put in perspective. Careful use of noise reduction software will make a big difference too. Even my EOS 5D3 isn't bad at ISO 6400 even though it's long in the tooth now. What is accepted as the norm changes quickly an our expectations do likewise, perhaps unfairly and with unnecessary dissatisfaction with results which in the main are still fine. You may hear the term 'usable' ISO. That's rather misleading as they are all 'useable'. What's really meant is that some don't like to see very noisy images, but for some in the photojournalism world they take as high an ISO as they can get come wha may if that's the only way to get the image.



ISO 12800 at a rehearsal in Tewkesbury cathedral


Diffraction, which was the subject of one of my recent blogs, causes softening of an image to varying extents dependent on aperture and lens design. How much it affects the image and how much it matters will be crucial to some and a small irritation to others. Indeed some may not even notice (or care) especially if the images is viewed small or downsized.

Converging verticals aren't an issue with equipment per se. They are the result of viewpoint and camera angle. They can be used to effect, so care is needed with composition, but it's the images where the convergence looks awkward that are less readily accepted. If they're in the background the main subject should take centre stage so odd looking verticals may not be a concern. Then there's how much 'correction' that's needed in order to bring them into line with what our brain does automatically. It's often that only 95% correction looks more 'natural' as we expect the top of a (tall) building to be smaller as we look up because we know it's further away. Full 'correction' can make the building taper outwards and give the impression it's larger at the top than at the bottom (though the Walkie-Talkie in London challenges that). Our brains find that hard to accept albeit geometrically more accurate.



A 100% crop with further noise reduction applied via Nik Dfine


Lenses are not perfect. It's true that there are some very good ones. These 'imperfections', even 'defects' are seen by some as 'character'. Chromatic aberration, barrel and pincushion distortion can all be rectified in software. Others, such as poor edge softness at wide apertures can't be resolved (no pun intended) and have to be endured, but depending on the nature of the image (for example a central subject) or the need to get a shot (as in newsworthy reporting) this may well be of less significance. Then there are those that take it to the extreme and use Lensbabies purely because of these properties. Go figure (again no pun intended but for figure studies they can yield appealing results).

How much or how little these concern individual photographers will vary widely, that should go without saying, it's up to us to determine our individual acceptance level. Keeping things in perspective and being aware of differences will definitely help.

I've only discussed some of the physical properties that affect images. What's acceptable aesthetically, and ethically for that matter too, are different ball games.


]All text and images © Keith Rowley 2021