K5 - Exposure bracketing for HDR

Must check my settings... because the last HDR set I did were bracketed on ISO (which is not what I wanted!!)

Matt

Like Smeggypants I too am impressed at the inherant dynamic range of the sensors in these cameras. But there are very real limits to what even these sensors can capture of the everyday world.

This whole question of whether to shoot bracketed exposures for creating an HDR output is surely related to the subjects each individual tends to shoot.

I used to banter with a work colleague about the De Noise process - I was right into it (still am) and he never bothered. But I was out in the countryside capturing scenes with deep shadows (lower foliage often) or dark areas on water, and I always wanted a perfectly clean sky. But my colleague's thing was studio lit portraits, and he couldn't usually see enough noise to worry about. Maybe this principle applys to dynamic range also?

If the levels indicator (on the histogram) is climbing up the edge at either end, then you can't get any detail back. You can lighten the shadows for sure, but it goes a weak discoloured looking tone and of course the dreaded noise appears. If you shoot 5 brackets (making sure the shadows are well away from the left edge of the histogram in your brightest shot), then the HDR processing will reveal a purer dark tones with less noise in the shadows - overall a higher quality is attainable.

It can be well worth the time.

Just an afterthought - in relation to the questions about bracketing exposures by altering ISO values (you'd expect this to occur in TAv mode - but apparently it doesn't), I can't see much argument in favour of this.

If you're considering HDR for a particular scene, then your primary concern is presumably attaining the highest quality. You're trying not to compromise the quality of the extremes of your image at the dynamic limts (in terms of visable detail, noise interferance, and a pleasing balanced contrast).

Therefore you should be aiming to use the lowest ISO value possible under the shooting conditions, namely the general brightness of the scene, the aperture and whether you are handholding or not. It seems to me the only process of bracketing with any validity would be varying the shutter speed - so I am really saying you should only shoot brackets in Av mode at a low ISO! Nigels HDR Rule 1.

I agree with Nigel's previous post, but also with Smeggy if using the K-5. In most cases bracketingis not necessary and you can get a great HDR image from a single RAW file. The most important aspect is not to burn out highlights as these can't be recovered, but pretty much anything else goes.

Regards
David

All fair points. I think we need to make the choice of what techniques to use based on the intended output. We don't always have to strive for the ultimate quality, although I have been snapping on holidays and later realised I had a cracker, but the DR has been blown and I'm kicking myself for not taking the time to bracket for further HDR processing.

By the way, if you're careful and you're shutter speeds remain high enough even on the longest exposure, the software is capable of ensuring even hand held bracketed shots are perfectly aligned. I tend to use the technique of holding breath to keep the camera in the same position - and also set the camera menu function for 'One-Push Bracketing' .This means that one inital press of the shutter will fire off the 3 or 5 brackets automatically, so no pressing down again each shot. The results handheld are much better aligned.

It does depend what you want. My technique is to shoot either 5 or 7 shots, separated by half a stop or even a full stop each. This produces a lot of information that can be handled to suit.

The usual program is Photomatix and this can give a variety of resulots from very natural looking, but with even the most extreme shadows and highlights full of detail, to quite outlandish.

Yes, if you are street shooting or taking travel shots then mostly our DSLRs can provide plenty of dynamic range - as smeggy said you can recover a number of stops from dark shadows. I wouldn't say the same of highlights though, where in digital blown highs are only acceptable in 'hotspots'.

But for professional reproduction or exhibtion sized prints I would be looking to HDR techniques to assist me. I know HDR has a bad press due to all the extreme examples we've seen, but I am attracted to it as a means to achieve true realism, to show the scene just as our eyes would interpret and adjust for the full dynamic range.

I was taken with a comment earlier when a member said that HDR and 'purist' don't go together. I will stick my neck out and claim that the opposite is the case. By 'purist' we are presumably meaning the output that any individual camera is capable of without further software processing. This surely is only 'pure' in relation to this camera.

For me a 'purist' image would be one that matches the scene that my eyes can see - and this often means a much wider DR than any individual shot can present. So by using HDR to achieve this we are in fact approaching a 'purist' result.

The little K-x has the exposure bracketing and the mirror-locking 2-second self timer as two alternative settings in 'Drive Mode'. In other words, one cannot have the mirror locked up for tripod work and at the same time use the camera's auto bracketing. Annoying. I have just tried the 'Live View' trick. It does allow bracketing, but also annoyingly the mirror flips down and up again in between the 1st & 2nd and between the 2nd & 3rd shutter actuations. Pointless!

As for the suggestion that bracketing is unnecessary because one can recover so much from a RAW file with editing software - my view is that bracketing takes up much less of one's time than fiddling about with shadow and highlight adjustments in Photoshop or whatever.

Martin

How is that? In Lightroom ( can't speak for other software ) adjusting shadow and highlights is just 2 sliders and accomplished in seconds. I can do multiple photos in the same time just by selecting them all and tweaking the sliders.

I'm not sure that taking bracketed shots and messing about merging them could be any quicker?

Quicker isn't always better though. It depends on our own approach and what we are tring to achieve.

Some will batch process images, and I've never seen the logic in that as every shot may need a slightly different adjustment. Some may spend literally days or weeks fine tuning a single image. I certainly don't have the patience for that.

No approach is necessarily wrong, if it's the way to achieve what is visualised.

Although I agree with the statement, given OldTaffy was specifically talking about the time taken and I as responding to that , I'm not sure how it's relevant?


Every shot is indeed different. However probably 80% of the processing of similar shots is the same. There's no point in repeating editing steps for many photos, therefore I multi select many similar images in Lightroom and edit them all the same. I then, importantly, tweak each image separately in regard to it's individuality.

I don't think I've ever spent more than 5 minutes editing a single images, except for old film scans where the colour balance needs a lot of care


I doubt anyone would argue with that.


anyway, I returned to this thread as I just created a HDR image from the current set of Olympic torch pics I finally got around to processing.

Single image taken on K-5, edited in Lightroom and using Color Efex pro plugin detail extractor. I'm not a huge fan of HDR and was just messing about so thought I'd post it as an example ...

Smeggypants has posted an HDR image of a type that could not be created with multiple images - a moving subject. In this instance I'm sure the in-camera HDR is an interesting possibility, as is the multiple processing of a single RAW capture. A single JPEG could be used to make an HDR image, but it's a bit iffy as a process.

how do you mean?

I can see how detail can be brought out and it shows how HDR can be produced from a single image but I feel its type image doesn't sit well as HDR makes the policemen look as if they need a good wash and they stand out too much.
Not that I'm an expert but just an opinion based on taste.

You can create a pseudo HDR from a single image by processing it with various degrees of + and - EV correction, then processing the resulting versions with HDR software, or alternatively, just adjust shadow and highlight correction on a single image.