HDR photos vs Raw shooting

bluechair84

Right, I've been playing around with HDR photos - doing them in paint.net to edit three images then alter the luminosity/alpha ratio and layering them up. The problem is getting three exactly the same images without a tripod.
So someone suggested I shoot one photo in RAW, edit it three times then merge it. So, I have PS4 tried this a few times and was fairly impressed with the automerge function.
Now, I take one photo in RAW and use the RAW editor. Use recovery on the light areas, increase the exposure on the darker areas and then a little colour fidling. It seems to do the same job as merging three together - Anyone else use this trick of creating an HDR image out of a RAW file, and avoiding the need to merge? How do you find it compares?

sheepsteeth

what the fuk is a hdr photo and why would you do it?

bluechair84

OMG...

Something I know that the Sheeps/yeehaa monstrosity hasn't successfully responded to!? This shall be savoured....

hdr is high dynamic range, it is a photo that exposes better than a normal photo. cameras can't detect light across as broad a range as the eye can so you have to take two or three photos, each one exposed for a particular area of the picture. Like you have a sub and tweeters that produce different parts of the sound wave because the cone can't handle the full spread.
F'rinstance;


With the grave n minster exposed correctly, the sky was blown out. HDR = success!

The thing is, you can adjust the picture in a raw file (as opposed to a jpeg) at the exposure level - so by increasing the exposure of the dark areas and 'recovering' the over blown sections you technically get an HDR... seeing as there's quite a few people that like their photos on here I wondered what people's thoughts were compared to taking thrre photo and layering them up, but I reckon this thread is gonna die quite soon...
:oops:

Gazlar

I dont like it, it looks too superimposed, thats the problem when you try to make things look too perfect, one of the joys of life is imperfection

peterst6906

It's not the ideal technique and while the results will often look good, you'll get a better result from 3 RAW images of different exposures.

However, without a tripod and no other way to stabilize your camera, it is one way to try to compress the data from the RAW into an image viewable on screen or in print.

The reason that it is inferior to using 3 RAW files is that you are still limited by the dynamic range of your camera system (sensor, optics, A/D conversion) in terms of the number of stops of light you can catch.

In general, a RAW file on current cameras has a wider dynamic range than you obtain once the single file is converted to a jpeg, but you are still not able to capture more dynamic range than you can obtain from the single capture.

By combining three (or more) exposures, you can capture more data in the shadows and highligts and then compress that into a single image through the tone mapping.

By capturing the extra data and adjusting the exposure of the captures, you obtain more levels of difference in the shadows (by overexposing the image) and the highlights (during the underexposed images) and so retain more detail.

But, in any case, processing a single exposure several times and combining them may be the only option you have sometimes.

Regards,

Peter

Gazlar

^what he said

Anonymous

bluechair84 wrote:

OMG...

Something I know that the Sheeps/yeehaa monstrosity hasn't successfully responded to!? This shall be savoured....

Well I'm actually a dab hand at HDR, and RAW processing, but if you're going to be a dick, then stuff you. :roll:

bentes

I agree entirelly.

peterst6906 wrote:

It's not the ideal technique and while the results will often look good, you'll get a better result from 3 RAW images of different exposures.

However, without a tripod and no other way to stabilize your camera, it is one way to try to compress the data from the RAW into an image viewable on screen or in print.

The reason that it is inferior to using 3 RAW files is that you are still limited by the dynamic range of your camera system (sensor, optics, A/D conversion) in terms of the number of stops of light you can catch.

In general, a RAW file on current cameras has a wider dynamic range than you obtain once the single file is converted to a jpeg, but you are still not able to capture more dynamic range than you can obtain from the single capture.

By combining three (or more) exposures, you can capture more data in the shadows and highligts and then compress that into a single image through the tone mapping.

By capturing the extra data and adjusting the exposure of the captures, you obtain more levels of difference in the shadows (by overexposing the image) and the highlights (during the underexposed images) and so retain more detail.

But, in any case, processing a single exposure several times and combining them may be the only option you have sometimes.

Regards,

Peter

delta5

Using one image doesn't really count as HDR because you are still only working within the dynamic range of one exposure. Even with RAW there are limits to how far you can alter exposure (max of about 2 stops) without introducing a false, flat effect in the highlights and some shadows. In the minster image, although it seems to cover a wider range, it's been at the expense of contrast and saturation - the walls and roof lack contrast and saturation which leaves it looking washed out.
For proper HDR with good saturation you really do need to take at least two exposures so that the highlights / shadows in each are optimised (i.e. mid-range) not pushed to the limits of their exposure curve.

If you do have multiple exposures, tone-mapping and HDR tools like Photomatix are great. It can be installed as an add-in to PS, Aperture, Lightroom, etc. I think the basic version is free.
Another freebie is CombineZP which I use for some HDR but more for other types of image stacking.

Slightly ot, but one I find far more interesting and useful than HDR is image focus stacking - a way of creating images with much more depth-of-field than is possible even at f32. For example you can take multiple exposures of an object, moving the focus slightly between each, then use CombineZP to stack them into one image with immense depth of field. It requires some trial & error, and a good tripod, but can produce amazing results. One I'm working on at the moment is a saxophone shot end-on, with all the keys in focus. Here are two much simpler examples. Each is made from a stack of only 6 exposures.

pepper series A image #1 - only nearest seeds in focus


(images #2 - #5 not shown)

pepper series A image #6 - only furthest seeds in focus


pepper series A images #1 to #6 stacked - all seeds in focus


Tuscan roof series image #1 - only foreground in focus


(images #2 - #5 not shown)

Tuscan roof series image #6 - only background in focus


Tuscan roof series images #1 to #6 stacked - all in focus


Strange stuff to be posting on an MTB forum at 12:30 am . .

sheepsteeth

those are brilliant looking.

playing with depth of field is my curent fave thing as the new camera andlens is more effective than any i have used before. i am delibrately trying to take shots with a narrow DoF because it is new to me and i think it looks interesting.

the final shots in those processes are outstanding (even to my amateur eye).

heres a question for the pjotography types: are post production alterations cheating or are they part and parcel of photography?

i like trying to take shots as well as possible in the first place and hope to not to have to touch them up (i know the example of the pepper and tiles above are a different thing entirely) is touching a photo up cheating?

Anonymous

Post production is just another aspect of photography, sheeps. People used to manipulate their images long before digital cameras and PhotoShop came along. In fact, most of the PhotoShop techniques and language come from the old film days.

bluechair84

yeehaamcgee wrote:

bluechair84 wrote:

OMG...

Something I know that the Sheeps/yeehaa monstrosity hasn't successfully responded to!? This shall be savoured....

Well I'm actually a dab hand at HDR, and RAW processing, but if you're going to be a dick, then stuff you. :roll:

Jeesus, take it as a compliment, you guys tend to have most knowledge basis well covered so it's happy days when i can contribute. You'd make an ideal frankenstein's monster's brain! I've thanked you many times before and wasn't being arsey.

Anyway, so trying to create an hdr from adjusting the exposures of certain areas of your frame from raw can't produce as good-a finish as three layered photos? Isn't it effectively the same thing? I'm very much learning so don't want to pick up a bad habit. Mine isn't brilliant but the minster was a good learning subject. This is actually a three layer, i don't have one of the single image raws to hand to compare.

And i'd never considered multi-focus shots, that's brilliant.

Anonymous

Oh, so you weren't saying "here come the trolls"?
Fair enough.
In that case, yes, you can do HDR with one raw file. Sony slr cameras Excel at it because they have absolutely bonkers headroom in the raw file.However, using several exposures lets you capture a vast dynamic range, much moreso than a single exposure on any camera.
When taking the shots, be sure to leave the aperture the same, and change the exposure by varying the shutter speed, otherwise your depth of field will vary between exposures.
A solid tripod is a must, as is a remote or cable, release.
Nikkon cameras have crazy bracketting options, making them ideal for capturing shots for HDR, but if you want to capture the widest range you'll be better offadjusting the after speed manually, to make sure you've got the darks, mids and highs covered.

bluechair84

i'm riding chicsands today with the dslr, i'll be shooting in raw to then muck about with the dynamic range in PS to try and get nicely exposed shots. I'll drop some in after the weekend, then there'll be a comparison. Love to see anyone else's (preferably riding?) shots with hdr wizardry thrown in

Treguard

The iphone sort of does this, but more often that not unless you're standing perfectly still you end up with ghosting (e.g. double of everything in the picture which isn't nice). It also disables the flash so I'd advise using sparingly if an iphone is indeed what you're using

delta5

Thanks for your comments on the focus stacking - it is cool stuff to play with. Just wish I had more time to spend on it.

Sheepsteeth wrote:

heres a question for the pjotography types: are post production alterations cheating or are they part and parcel of photography?

i like trying to take shots as well as possible in the first place and hope to not to have to touch them up (i know the example of the pepper and tiles above are a different thing entirely) is touching a photo up cheating?

Post pro can be whatever you want it to be. It's not cheating - from a creative pov there are no rules - but talk to photographers and you'll get a range of opinions from the 'no-post-pro' purists (often old-school slide-shooters . . a bit like fixie riders in a way ) to the 'anything goes - go mad and see what happens' mob. As Yeehaa said, its nothing new - cropping, altering contrast, dodging and burning were darkroom techniques long before computers even existed. However computers let us do the same things (and a few more) easier, quicker, cheaper, reversibly, and without the nasty chemicals. Ultimately what is acceptable alteration depends on the intended use of the image, and ranges from 'no holds barred' in creative & abstract photography, through moderate in portraiture and documentary work, to little more than cropping being acceptable in news journalism (although that doesn't stop creative things from happening there - you might recall this one! ).

You're absolutely correct to try to get it right in camera. It will save you loads of time in post-pro. If the RAW is good you can work it in software - but you can't polish a turd. When first getting into digital editing many people tend to overcook their images by tweaking everything, and end up processing them to death. Unless you're going for crazy effects, most images of any worth need very little post pro - perhaps slight changes on the tone curve, some cropping, and judicious use of unsharp mask. Some need straightening, maybe shadows recovered, or colour balance fixed. If I find that an image requires much more than this, I ask myself 'what is it about this image that justifies the time and effort?'. If I can't answer that, it goes straight in the 2nds folder.

Bluechair84 wrote:

Anyway, so trying to create an hdr from adjusting the exposures of certain areas of your frame from raw can't produce as good-a finish as three layered photos? Isn't it effectively the same thing?

No . . . although it might look similar, you have not actually increased the dynamic range at all - it is no 'higher' than what was captured by the sensor - it remains as it was in the single exposure. You have lightened some areas and darkened others (i.e. changed the ratio of light:dark pixels), but only within the tonal boundaries of that single image. You have not expanded the tonal range.


Late again . . riding tomorrow so time to pack it in.
Here's a parting shot Londoners might recognise - neither HDR nor stacked . . .

ollie_lucas1985

Just type HDR into google and you will see the attraction.. for example:

ollie_lucas1985

Just type HDR into google and you will see the attraction.. for example:

bluechair84

Terrific responses guys, thanks very much.

Just got back from chicsands and also rode the black runs at Sherwood Pines to boot so my replys were limited to what I could see on my phone - I wanted to respond to Yeehaa rather than leave you under the impression I was being a cock. I will actually leave the impression of me being a cock to the drunk b@stard who thought it would be funny to play chicken with me in Hertford Saturday night. I think he nearly pooed himself when I called his bluff and accelerated at him.

Anyway, my learning today comprises of - RAW exposure fiddling improves the dynamic range of the photo but still introduces artifacts and weaknesses in the photo as a whole, and three layers is always the way to go for proper nice photos. And focal fiddling demonstrates just how much I have to learn beyond just moving some sliders around in photoshop :oops:

Ollie; good effort with getting a bike related HDR in the thread

Anonymous

Can't say I'm a big fan of HDR, but mainly because most HDR stuff posted on the net is way over processed and just looks artificial or alien. Also find it (jealously) annoying that these are the photos that get all the attention because they are striking even if the subject may be relatively dull. It's a bit like putting black borders on your photo which makes them stand out. I like photos to speak for themselves and not be tarted up, but then a lot of photography is about just that.

A subtle HDR is okay though, but I don't usually bother as it's a lot of hassle processing.

It's a lot easier with the right software, but good ones cost money and I'm too tight. Still, did a test HDR shot and managed to process one using Picturenaut (which is free/donationware) based on three bracketed exposures. Didn't use a tripod. Not a great example, but has a bike in it (and yes the idea was to silhouette the bike, and normally that would result in blown sky).

bluechair84

Very nice. I'm quite a fan of HDR, I think it actually improves an otherwise dull subject because the exposure allows you to see more than normal - but it won't ever replace a keen eye.
That's not this weekend is it? I don't think I saw any blue sky All pics I took this weekend were underexposed.

Anonymous

Mine was taken back in November at Coed-y-Brenin. Surprisingly sunny day for North Wales in November.

delta5

deadkenny wrote:

. . . most HDR stuff posted on the net is way over processed and just looks artificial or alien.

A subtle HDR is okay though, but I don't usually bother as it's a lot of hassle processing

I agree, a lot of HDR images look contrived and artificial, mainly because people get carried away with the effects and impact of gritty, contrasty images. The photo of the bike & river is a good example - colours over-saturated, too much contrast, and no detail in the shadows. That is not what HDR is about.
A proper HDR capture exposes for the shadows so that details there are visible - and exposes for the highlights so that details there are not burnt out. It is subtle, and in most cases you can hardly notice it's been done, as the results look very natural.
Pushing the contrast and saturation beyond that is what produces those unrealistically thunderous skies, and the shady areas that somehow look sunlit. While there's nothing inherently wrong with that - it can be very interesting and attractive - it can also very quickly become too much of a good thing. It's the rich food of photography.

I'm out in the sticks on my laptop now but when I get back to base I'll see if I can dig up some examples of good HDR to illustrate the point.

Anonymous

ollie_lucas1985 wrote:

Just type HDR into google and you will see the attraction.. for example:

Whilst that is processed to oblivion, I don;t think it's a very good HDR job. Since, there's not much dynamic range in the image. The highs are still clipped, and the lows are all clipped out. Very odd.
Looks more like just crazy saturation, or an orton-effect type thing.

Oh, and talking of crazy HDR. Here's one of my intentionally processed to hell and back HDR shots. But I still like the mad effect

bentes

Nice photo Yeehaa!
Thought I'd share a few of mine too...

Anonymous

Nice! Those show the difference between multi exposure HDR, and my single exposure one. I didn't have a tripod, and the river was moving too fast, so I used a single shot.