Love it, this one always makes me laugh!

Another good one Don, so colourful!

Well ISO affects the amplifiction of the signal at point of capture, sort of like audio ‘gain’. There is similarity in the processes of controlling this on the camera and later on the computer. Look at some of the stuff Algernon has linked to about ‘ISO less’ sensors, and in that case it apparently makes no difference whether the signal is amplified at capture or later. But this only applies to certain sensors.

What practical purpose it has is questionable really, because shooting at high ISOs has a real functional purpose in aiding the photographer ( eg allowing shorter exposures) ...... if we were to always shoot at base ISO then we wouldn’t be able to hold the camera steady for many shots, or see anything on the LCD if it was a dark scene and deliberately underexposed.

Personally I believe it’s best to optimise the shot at point of capture ....that means the best possible exposure value, and best possible balance of ISO, aperture and shutter for the conditions. The further away from the ideal for each of these when the shot is taken, the more compromises will need to be applied in processing to fix things.

I add white balance to this also, even for RAW shots. But some aspects, colours and saturation, fine contrast adjustments, detailing and sharpening, and of course cropping/levelling are more easily optimised on a computer, with no real loss of quality.

Aperture is an optical setting, not a software one. Once the shot is taken at any given aperture, that is it .... It cannot be changed by processing.

Here's one more, hot off the press! Same shoot, same settings etc …..

Some real drama whipped up there!

Not at all, keep it coming! From my point of view, I'm seeing Radio P-TTL as not an expense at all ....I already had the gear which provided Manual HSS. The P-TTL came courtesy of free firmware from Cactus....a really nice treat and bonus from them, thanks Cactus!

Does that side with Algi?

There's always the ETTR camp ....(expose to the right). The problem with that is that it's often too hard to do that without clipping whites.

If you're a K5 user then you're supposed to ETTL!

Well sure, but that's not really optimising the exposure or getting the best possible output, it's really a technical compromise for when the DR exceeds the sensor's capability. A good one, but still a compromise.

You get the best quality by capturing the best exposure when you click the shutter. With the histogram now we are spoilt in being able to judge this. We can ensure the highlights are not clipped, and the midtones are well placed around the centre and right third area on the graph.

Getting this right at capture ensures the best range of image data is recorded, giving the potential for the best possible IQ once processed.

Of course we cannot always achieve this in one exposure, if the dynamic range is high but that is really a different question...... It should be the aim to optimise the exposure value at capture if the DR allows all tones to be recorded.

We should not use bracketing as a sort of hit and miss safeguard now, there's no need for that with digital imagining.

Still not yet convinced on Radio P-TTL ? Well, I'm still working on you.....I reckon we'll have some Cactus or Godox gear in your shopping basket before long Stuart!

I see a strong practical case for TTL flash control, especially when outside and mixing flash with natural light. Here it is very efficient to think mentally in terms of "stops" for both ambient and flash exposures. So I might think I'll keep ambient at -1.0 or -1.5 stops below meter, but then place the flash value at -0.5 ..... This makes the ratio and mix I'm looking for, and it's easy to relate the two as they are thought of in the same units...... Rather than the flash setting being a power figure (eg 1/8th or 1/32) that bears no obvious relationship to the camera settings.... In fact no relationship to anything really

Regarding the HSS, take my 3rd shot here .... The light got very bright and glaring, and I was already using ISO100 and F11 ....I needed another 2 stops of light reduction to get the white blown out highlights down.... So I moved the shutter speed to 1/750th. The HSS mode kicks in automatically allowing me to keep using the flash to provide the nice soft directional light, and the exposure is kept under control, retaining the textures and colours of the flowers.