Pentax Camera Image Controls vs Computer Editing

read "conceiving", we are British not American. Another bugbear of mine.

What you describe is also my experience, John. I would also add that adjustments to the camera JPEG files can be made in software, without any discernible loss of quality up to at least A3. There is no doubt that the maths shows more latitude in Raw data files but, most of the time, I have not found it to be necessary in producing the final image. But again, to each his/her own.

Cheers.
Philip

No worries Richard, frankly these sort of debates tend to take on a life of their own .... certainly I, as the instigator, usually find it's hard to keep the troops in line! Look, already just above its morphed into the RAW vs JPEG quality debate

Getting back on track, let me refresh that I am limiting my definitions and the thinking behind it entirely to the camera controls ... the things we set in advance to pressing the shutter .... so everything should here should be considered as entirely at the capture stage. This is not about post processing. Both the camera 'input' controls (which affect the optical system and sensor recording and any artificial lighting involved) , and the 'output' controls (which affect the in - camera processing and the image adjustments carried out by the camera) are all set up on the camera itself. I am creating a division between these controls, grouping them in this new manner, in order to aid understanding and agreement on their potential effects as they relate to any later 'photoshopping' .....

Let me repeat the category divisions and listing here ....

1) Input Controls directly affect the 'physical' optical image capture ...how the camera optics perform and the way the sensor records that optical image data.

So these input controls are .... a) Aperture b) Shutter Time Value c) ISO d) The focussing controls, whether manual or using AF points e) Flash use and flash exposure settings


2) Output Controls act to adjust and alter the results from the input control settings ... ie, they apply computer controlled software adjustments to the digital imput file, which is effectively a RAW file inside the camera.

So these output controls include ... a) White Balance b) All the Custom Image settings ie Preset, saturation, hue, high/low contrast, sharpness, fine sharpness etc, filters for Black & White or other effects etc c) the highlight / shadow corrections, lens distortion corrections d) the HDR controls

To follow from John above and further answer Nigel's question, its correct that in fact none of the Output controls listed will apply ( I mean 'be applied') to a RAW file. However, even if your are shooting RAW only, all of these settings are in fact active, and the processor does apply them .... but only for the image review on the rear LCD and to create a tiny embedded JPEG inside the RAW for catalogue thumbnails. For this reason, if you shoot RAW only, then you should switch off those Output controls that cause a longer processing time ... these are the shadow / highlight corrections and the lens corrections.

Glad to have you joining in What do you think of my classification of the camera controls ....? will it help with the issue of 'photoshopping' when we debate it?

i think you will find white balance is applied to RAW files

Yes, I see your point .... it actually is recorded and its effect takes place, true. The difference is that WB is one setting that is often claimed to be variable after capture in RAW, without quality loss. I'm not sure myself why this would be the case in technical terms? It depends on whether that is true I guess.

I have actually found in practice that it is not always easy to correct White Balance issues, even in RAW, if the setting was wrong in the camera. Sure, minor colour balance tweaks are OK, but I've never had much success with major white balance settings that were wrong.

Perhaps I should re-classify White Balance as an 'Input' Control ..... ?

If you shoot RAW then you can choose the WB setting after the event, certainly in ACR.

AWB is something I avoid, except in severe mixed lighting, because I tend to want the ambient colour of the light to be retained. For the same reason, I change the setting to a fixed value, otherwise the camera will continue to make judgements within a limited range regardless of the setting.

The most suspect condition for Pentax cameras seems to be deep shadow on a bluish winter day, where things rapidly turn purple. The "shade" setting corrects this well.

Nigel, does this qualify as minor or major colour balance error? - The White Balance was accidentally left on Tungsten from the evening before this shot of a church on a cloudy day:




This was result of applying Auto white balance in ACR and the Auto corrections in Elements 10:




It was then edited further in PaintShop Pro X6:




The original blue image was a 16MP 4-star JPEG image from the K-5 II.

Cheers.
Philip

Yes, thats true, and we have the same WB pre-sets in PDCU. The question is, does making this adjustment in Post Processing actually result in the same colour quality than if we had chosen the setting on the camera? Or will it cause some degradation by being the result of a software manipulation? Its about the issue of whether this colour toning is 'Baked In' to the RAW in some way?

Philip, I find those white balance corrections very successful! So does this in fact suggest that we need to leave the White Balance settings as classified as an 'Output' type?? An output setting is something that can be easily and normally adjusted on a computer, and can't be labled 'cheating'

You must have space for a whole colony of bugbears if you get irked by the ineluctable process of language exchange.

I take it that the blue sky of nos. 1 and 2 is caused by an incorrect WB, put fully right in no.3(?). But something is not quite right with the ridge tiles in no.3, which change in colour half way along the nave.

When I remember, I usually shoot jpeg+RAW. I use the jpeg only as a reasonably standard reference to gauge broadly what colours the camera saw. Of course sometimes I 'improve' on nature, but at least I then have a sense of what I'm departing from.

You are right, Christopher. It was a dull day with grey cloud cover, some quite dark. Your observation re. the ridge tiles is also correct, but it is entirely my fault. It was a rushed job just to see what was possible - I made a duplicate layer to alter the sky, and didn't take enough care with the brush at the roof line.

Cheers.
Philip

That's my take on it, in that a WB suggestion is inserted into the RAW info and this is applied on opening the RAW file, but you are free to adjust it as required, without quality loss.

Agreed Nigel,

In this instance I used the term conceptualising, with reference to visualising a concept. Conceiving would fit also, but I felt conceptualising conveyed my intentions more suitably, and potentially more directly than conceiving.

I do hope my choice has not caused you too much distress, and hasn't prevented you from contributing further to the actual thread topic.

Use of the term link 1

Use of the term link 2

I am not quite sure yet where you are going with this thread, Nigel, but my understanding of what happens in the camera is rather different. Unless I am mistaken, the ISO setting does not affect what is captured by the sensor.

My understanding is that the ISO setting determines the extent to which the voltages stored in sensels at capture are amplified before the RAW file is created. Depending upon the camera marque, this amplification might be analogue if it takes place before A/D conversion or digital if it takes place afterwards - or both. Maybe the boundary you draw between input and output controls should be the raw file, rather than the voltages stored in the sensor at capture.

My understanding of the WB setting is that it merely acts as a user suggestion to the RAW processing software, whether this is in camera or otherwise, of the WB to be applied when output is created. It is used in creating images viewed on the rear LCD screen of cameras. If you are shooting JPEGs in camera, it will be used in the creation of the JPEG. If shooting only in RAW, it will be used in the creation of the JPEG preview stored in the RAW file and is also used by external RAW conversion software to create the image viewed onscreen when a RAW file is opened. I do not believe that it affects the content of the RAW data itself.

Andrew