First Attempt at HDR - Elements 10, CS6 (not mine) or a special programme please?

[Bettyboo]

Hi All,

For the first project on my current C&G photograph course, I have produce an image with an HDR effect. I have read some of the threads on CIC and they have been extremely helpful.

I have Elements 10 which I am very new at, very At college we have access to CS6, but I only have a very limited time available there, which is basically after the class for an hour or so once a week.

So my question to you guys is: do you think I might get a good enough HDR image from using the 'Blending Multiple Exposures (aka psuedo-HDR Techique) as per Scott Kelby's book in E10?

OR should I try and do it on the college's CS6 ?

OR should I purchase one of the programmes as mentioned on Trey Radcliff's free tutorial please?

As this is my first attempt, I don't know at this stage if this is a technique I will be using a lot in the future, so I am alittle reluctant to buy another programme if I have a chance of putting together a half decent version using E10 or CS6. However, I do want to do well on the course, so if that is people's best advice, then I will raid the Christmas fund and get one of the special programmes.

Sorry for rambling, any advice is most welcome.

Best wishes,

Lynne

[ajohnw]

There are 2 free programs I want to try at some point for this. One is Luminance HDR and the other a program called Enfuse but that one is a command line program - no graphical user interface. There is a link on the Hugin site in the tutorials that runs briefly through using Enfuse. Odd names maybe but google will bring up the sites the sofware is on. I suspect that as the tutorial mentions that Enfuse is the easiest to use. They can be confusing programs as people have come up with numerous algorithms for blending exposures.

A quick check shows that there is a gui for Enfuse http://software.bergmark.com/enfuseGUI/Main.html for windows and mac.

Luminance looked rather complicated to me and newer versions than the one I have may be easier to use. The attraction of Enfuse is that aspect. The tutorial I mentions discusses work flows etc.

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[ajohnw]

You may also find this link useful. It's actually generating a fake hdr from a raw file - useful technique. No need to use the Hugin facility to align the images then. The Gimp is also mentioned. A free photoshop equivalent in many ways. Youtube video's even explain how to make it look like it too and there are lots of tutorials. There is also the usual HDR available via the Gimp see http://gimpguru.org/Tutorials/BlendingExposures/ An infuse plugin isn't available yet. There are many others.

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[arith]

Here's one that works fine:

http://www.hdrlabs.com/picturenaut/

[herbert]

Hi Lynne,

People have already suggested good software to try. I would suggest that you then seek out a scene that really demands the use of HDR imaging techniques. Often people use HDR on a scene where the entire dynamic range (brightest point to the darkest point) can be captured by a single photo. The tone mapping tools used with HDR then make your image look unnatural.

The scene should be something with totally different light sources creating a big brightness difference among parts of the scene. Examples would be to shoot a candlelit room and try and maintain colour details in the candle flame. Or shoot the inside of a room looking outside through a window. The outside will require a very different exposure to the inside.

Basically search around until you find something where you cannot capture all of the scene at the same time without clipping highlights or losing details in the shadows. Keep your eye on the camera histogram and find a scene where the middle exposure is still touching both ends. Then bracket the shots so that at least one shot has no clipped highlights and one shot has no pixels near the shadows. A tripod wil help you experment with exposures while you try this out.

Enjoy experimenting.

Alex

[Bettyboo]

Hi John and Steve, many thanks for advice and links. I still have a couple of weeks before we go out on the shoot, so I will have a look at them all.

Thanks Alex for detailing your advice so clearly, that has really helped me to understand why I was bracketing and the potential problems. Unfortunately we have been given our subject a shopping centre and we are all going together on the 20th Nov, but that doesn't mean I can't practice both for this assignment and after as you suggest. A good time of year to practice the inside/outside shot, many thanks.

I have spent the afternoon finding how to bracket on my camera, which I think I have got the rudiments of now, so can now practice doing that with identifying suitable images and looking at the site John and Steve have given me, lots to be getting on with

Thanks again guys, much appreciated.

[FrankMi]

Hi Lynne, I'm not sure what you mean by an HDR Effect?

Does your result need to be an obvious HDR result? Does the scene need to be of such and extreme contrast that High Dynamic Range techniques MUST be applied or shadow and highlight detail is blown, even in a properly exposed image?

I think that part of my confusion stems from the fact that "HDR" describes the exposure range of the scene and not the processing that is used. There are a number of ways to deal with an ‘HDR’ scene that might, or might not involve using the typical HDR processing tonemapping techniques.

When HDR is done poorly it is very obvious owing to sickly skin tones, dramatic halos on high contrast edges, electric over-saturated foliage, and black clouds (to name a few). On the other hand, with a properly done HDR, it might not be possible to determine from the final image that HDR tonemapping techniques had even been applied.

There are some obvious situations where HDR techniques had to have been used owing to the image results. Here is an image that was processed with an HDR tonemapping technique (using Photomatix Pro) in order to get the details in the fireplace and outside the building with just natural sunlight.



On the other hand, one might think that the following image was done with HDR but it was not. Three AEB images at -2EV 0EV and +2EV were used, but only the sky was merged from the under exposed image and the fence was merged from the over exposed image in Photoshop using layers and masking. This could be done in Elements.

[Bettyboo]

Hi Frank,

I take your point and the images are lovely. All I know at the moment is that it must be obvious that some kind of processing has been done after the image was taken and the tutor mentioned a 'HDR effect', so I thought that would be the most visual example.

But I can see what you mean and if I was going to us it, then I suppose I would be looking for something exaggerated to demonstrate that?

I can think of one part of the shopping center, outside, that would be covered by a walk-way so I could stand under that, looking out into the the rest of the open area of the center, perhaps that would give enough DR?

Boy am I glad I asked two weeks before the assignment! I definitely need to read through all of this and practice even more!

Thanks again Frank, the examples have helped me visualise what I am aiming for, I hope!!

Best wishes, Lynne

[Colin Southern]

Hi Lynne,

People often confuse an "HDR Look"with Tone Mapping - the two are often used together, but they're not interchangeable.

HDR is a technique used to capture the dynamic range of a scene that's too big to capture in a normal single exposure (so multiple exposures or GND filters are used). Tone Mapping is used to squeeze the resulting wide range of tones into a smaller range that can be displayed on low dynamic range monitors (and in prints), and it's this tone mapping that quite often results in an overly clarified & over-saturated look that's often mistaken for HDR because it's possible to achieve the same look without using HDR techniques.

The usual "give away" is when folks come up with such an image and then say "it's created from a single exposure" (in which case it may look just fine, but it's not HDR - only tone mapped (or Ultra Tone Mapped). It's important to realise though that it's also very possible to have an HDR image that looks like every other normal dynamic range image. So HDR isn't a "look" as such.

Hope this helps

By the way, I thing Trey used Photomatix - it's not free, but they have a free trial (watermarked).

[ajohnw]

There seems to be some confusion in this area Lynne. HDR to many means merging several different exposures. I suspect that in this case HDR effect means tone mapping. Tone mapping can go 2 way after a fashion - tonal range / contrast range decreased or more usually used on it's own increased. Decreased isn't a good word to use really but say several exposures are merged it does include a decrease after a fashion. The other type where local contrast is effectively stretched is well illustrated here along with some tips about what to aim for when taking the shot. This is tone mapping over the top often seen on the web. Wish people wouldn't call it HDR as explained on the link. http://blog.tasuki.org/tone-mapping-with-gimp/

I suspect this is the sort of thing you are expected to produce. It doesn't need multiple exposures really. The contrast changes are over the top. This image illustrates this http://www.flickr.com/photos/jaredearle/2581870560/

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[ajohnw]

Hi Lynne,

People often confuse an "HDR Look"with Tone Mapping - the two are often used together, but they're not interchangeable.

The usual "give away" is when folks come up with such an image and then say "it's created from a single exposure" (in which case it may look just fine, but it's not HDR - only tone mapped (or Ultra Tone Mapped). It's important to realise though that it's also very possible to have an HDR image that looks like every other normal dynamic range image. So HDR isn't a "look" as such.

Hope this helps

By the way, I thing Trey used Photomatix - it's not free, but they have a free trial (watermarked).

Fine but when several exposure are generated from a single raw file and then merged that is still HDR. It's often much more effective than trying to produce a suitable camera curve. Where a single image is manipulated to give an hdr effect it seem to mean over top tone mapping but people are for some reason calling it HDR. Personally I don't think HDR really relates that much to tone mapping in it's usual sense.

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[Colin Southern]

Fine but when several exposure are generated from a single raw file and then merged that is still HDR.

No, it's not. The resulting composite can't have a wider dynamic range than the single source file that created it. If the information wasn't captured in the first place by the single exposure because it was either buried in the noise floor or blew out all 3 channels then no amount of exposure adjustment is going to make it magically appear.

It's often much more effective than trying to produce a suitable camera curve.

I agree, but it's still not HDR.

Where a single image is manipulated to give an hdr effect it seem to mean over top tone mapping but people are for some reason calling it HDR.

I know that they are -- which is why I try hard to correct the error before even more people start repeating it.

Personally I don't think HDR really relates that much to tone mapping in it's usual sense.

Until they invent monitors with higher dynamic ranges than camera sensors then tone mapping is always going to be needed.

[ajohnw]

Really wierd Collin I didn't know that the final jpg could hold the same dynamic range as a raw file, As to tone mapping and hdr I give up, They really aren't the same thing.

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[Colin Southern]

Really wierd Collin I didn't know that the final jpg could hold the same dynamic range as a raw file

Of course they can't Johhn - but what's that got to do with anything? If you choose to process multiple versions of a RAW file using JPEGs as an intermediate file then the final result may well include more detail than could have been coaxed out of a single mapping, but that's because jpegs discard a lot of information in regions that you're later wanting to reveal information from - which is why it's preferable to use RAW files in the first place. It still doesn't make the final result HDR though because that final result cannot and will not contain more information / detail than the original single capture. HDR isn't a RESULT - its a set of techniques for capturing the dynamic range of a scene that exceeds the sensor's ability to capture it satisfactorily in a single exposure.

As to tone mapping and hdr I give up, They really aren't the same thing.

Again, no argument there -- not sure why you're bringing it up? Tone mapping will always follow HDR though, unless you can show me a monitor with a dynamic range that exceeds that of a sensor.

[herbert]

Really wierd Collin I didn't know that the final jpg could hold the same dynamic range as a raw file.

Dynamic range is the difference between the maximum and minimum brightness.

The amount of dynamic range you store in a file is more related to your chosen file format than bit depth.

If you choose a 1:1 linear relationship, i.e. double the number means double the light, then the dynamic range that can be stored is the same as the bit depth. This is the format used for raw files. However for camera raw images dynamic range is less than the bit depth since there is noise in the data at the low end and you cannot determine the true value, so this part of the range is discounted.

If you choose a non-linear relationship the difference between maximum and minimum is up to you. E.g. you could choose a 2:1 linear relationship to store 16 stops of dynamic range in an 8-bit file.

JPEGs use a curve relationship. It can store more dynamic range than linear 1:1. E.g. the CiC tutorial states 18-stops for a gamma 2.2 curve:

https://www.cambridgeincolour.com/tu...amic-range.htm

(Note that the referenced tutorial on gamma correction is yet to be added.)

However the bit depth will limit the number of tones that can be recorded between the maximum and minimum. So if you choose a dynamic range too large for the bit depth you will get visible separation between adjacent tones (posterisation).

Alex

[Colin Southern]

(Note that the referenced tutorial on gamma correction is yet to be added.)

Hi Alex,

It's there ...

https://www.cambridgeincolour.com/tu...correction.htm

[Eric M]

Hi Lynne,

Take a look at Machinery 2. It is great HDR software at a reasonable price. http://www.machineryhdr.com/effects2/index_e.php

[John Morton]

High Dynamic Range imaging was first developed as a type of digital file format for 32 bit images produced through Computer Generated Imaging. HDR was introduced into CGI to give computer imagery a more realistic appearance, through more closely producing the luminance range that the human eye can actually see.

Digital photography was a relatively late adopter of HDR although most people now know of HDR through photography.

When we speak of "The HDR Effect," then, we are not technically referring to something which originates from this or that HDR software program for digital photography. We are simply referring to methods which make images appear to more realistically replicate what the human eye can see.

However, that probably isn't what Lynne's instructor has in mind; because now, for most people, "The HDR Effect" is in fact something which characteristically DOES NOT look like what the human eye normally sees!

Myself, I would need further clarification from Lynne's instructor because for me, the whole point of good HDR is that it DOESN'T look like something we wouldn't see with our own eyes...

[John Morton]

Here's a thought for you, Lynne;

A few years ago I dropped in on a friend of a friend, who has an 'art and furnishings' store. I've always admired how "interesting" her various arrangements throughout the store are, and I asked her if she would mind my setting up here and there throughout her showrooms to do a bit of indoor HDR photography.

Certainly, HDR is classically thought of as something for merging vastly differing luminous ranges within scenes; but there are in fact a lot of brightly lit and deeply shaded areas within most showroom areas; so if you are going to be shooting this project at a shopping mall, perhaps you might consider 'breaking from the pack' and trying some HDR product display photography while the other students are fighting over who gets the best framing of any particular window or doorway....

These are actually a little more on the 'classic HDR effect' side than what I usually do, but, it was a fun (and different) experience nonetheless!



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I was using my Shift/tilt (Perspective Control) lens for these so the depth of field is a little more than can normally be expected using a standard lens; and if fact, the scenes I chose to photograph were framed specifically to make use of that PC lens' ability to tilt its focal plane.

[ajohnw]

The wiki seems to think the same as I do about the term quote:

Tone mapping is a technique used in image processing and computer graphics to map one set of colors to another in order to approximate the appearance of high dynamic range images in a medium that has a more limited dynamic range. Print-outs, CRT or LCD monitors, and projectors all have a limited dynamic range that is inadequate to reproduce the full range of light intensities present in natural scenes. Tone mapping addresses the problem of strong contrast reduction from the scene radiance to the displayable range while preserving the image details and color appearance important to appreciate the original scene content.

There are better definitions about what this means in terms of the effects on contrast. Also if used sensibly it doesn't mimic hdr effects at all ie not as as obvious as in the shots John posted. Where it is useful is when dark areas of shots are bought up as it can be used to augment the contrast in them. Also to augment "flat" looking photographs. It can also often used to improve the results of the S shaped camera curve mentioned in jpg's.

There is a very detailed video on youtube called hdr II on the use of curves and levels referring to as tone mapping. In terms of the meaning of mapping they are as are straight brightness and contrast adjustments, camera curves etc etc. In all cases one tone is mapped to another. More confusion.

HDR is entirely different. Shots for varying light levels are merged is such a way that they fit in the eventual colour space. As pointed out there are also hdr file formats. Luminance HDR uses them. Another area really. No contrast manipulation is needed the exposures take care of that. They place the wanted light levels within the final colour space. Tone mapping is all about contrast manipulation applied to a whole image or a selection within it. Both techniques can produce subtle results where there is no sign at all that they have been used - other than in HDR where say a stained glass window would obviously be brighter than the interior of an unlit church. In fact many people use both techniques in a manner where it isn't obvious at all. Others make it obvious. Personally I am often not keen on that.

My real objection to using the term tone mapping interchanged with HDR is that it doesn't differentiate the 2 processes and in essence many operations on a shot effectively map one tone to another so why not call the lot tone mapping including simple brightness and contrast adjustments etc,

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