Blending multiple Images (working title)

Blending multiple Images

By Mike Otley

Ever since the invention of film, its ability to capture the entire breadth of detail across a high-contrast scene has been very limited. Even in today’s highly technical world, film latitude remains somewhat of a ‘Holy Grail’.

Just a brief moment to explain; when we talk about film ‘latitude’ we mean the film’s ability to capture detail in the highlights as well as the shadows of that scene without either ‘burning out the highlights to pure white and the reverse i.e. blocking up the shadows into pure black. Typically, print film has a latitude of 5-6 stops whilst transparency film is even smaller at >< 3-4 stops in real terms. (There are those who would quote differing figures but these are the generally accepted values).

Over time film evolved and the camera hardware got more technical to deal with the situation (check out ‘pin-registration’ on 35mm SLR’s) and then…

…along came Digital photography!

But, the problem of latitude limitation remained - despite the technology leaps and bounds. The CCD and CMOS sensors used in the modern top-flight dSLR’s have latitude constraints that are very close to that experienced by transparency film users. That said, things have taken a big step forward with the release of the Nikon D3, D300 and D700 dSLR’s with their all-new 14-bit algorithms (as opposed to the standard 12-bit software) – but the problem of limited latitude still remains as a major challenge to the photographer looking to deliver the utmost quality of work when shooting high-contrast situations.

This brings me neatly onto High Dynamic Range imagery (‘HDR’).

‘HDR’ is a way of significantly expanding the dynamic range (or latitude) of an image and has become very popular over recent times especially with the advent of many newer, less expensive programs attempting to emulate the market-leader ‘Photmatix’. To work effectively, HDR software needs a minimum of three separate images (preferably five or more) covering exposure values (‘EV’) 2 stops above and 2 stops below the recorded exposure for that high-contrast scene. This give the software between 12 and 20 stops of latitude to work with (4 stops/frame remember). Additionally, a tripod – or some form of firm support – is also needed to overcome any frame registration issues.

But this is not the only way to expand the dynamic range in an image. Adobe Photoshop has always had the ability to bring multiple images together in different Layers and so produce a finished image with huge dynamic range. But – this is only possible on processed RAW files i.e. TIFF’s etc which, due to the processing, will have lost some of the original data no matter how careful one is in using non-destructive post-production techniques.

So… what if we were able to combine multiple-exposed versions of a high-contrast subject – using the RAW files! (The Holy Grail – perhaps?)

Well…? Now we can.

Adobe Lightroom v2 has a new third-party plugin which will do just that – combine multiple-exposed versions of a high-contrast subject – using the RAW files exposed in the same manner as if we were going to use an HDR package.

The product is called ‘Enfuse’ and full details can be found at http://www.timothyarmes.com/lrenfuse.php. I will leave you to read through Timothy’s site to understand more. Please note that the software is 'Donate-Ware' - so do please contribute as this will allow Tim to continue improving this excellent product.

Working with RAW files makes an enormous difference – for obvious reasons but what impresses me most is the inherent natural look that the finished images have without that (sometimes) slight over-saturation that Photomatix files have – despite how careful one is to control it. (I am not a lover of those awful ‘offerings’ that appear from Photomatix which are supposedly ‘HDR’ images).

Lets have a look at Enfuse:

This image shows the original 5 Nikon NEF (RAW) files ready to be ‘Enfused’ in Lightroom v2 –

Notice the spread of EV’s and in the left window the lightest version of the 5 files.

Once the process has run in Lightroom, the file is exported as a 16-bit TIFF. It’s then re-imported back into Lightroom for finishing and the finished result becomes –

Just for comparison, here are the same 5 files processed through Photomatix –

Quite remarkable differences – across the board – not least of which is the time-line needed to achieve it. Using Enfuse takes a fraction of the time by any other method – and that is vitally important to a professional photographers workflow.

If you are into HDR photography where the image must look natural, then I would encourage you to try Enfuse. And if you haven’t tried Lightroom v2 yet. Well…!!



Mike Otley has been looking at the Enfuse plugin, which enables multiple image blending right inside Lightroom 2! Are there any benefits over dedicated HDR programs?

Blending multiple Images By Mike Otley Ever since the invention of film, its ability to capture the entire breadth of detail across a high-contrast scene has been very limited. Even in today’s highly technical world, film latitude remains somewhat of a ‘Holy Grail’. Just a brief moment to explain; when we talk about film ‘latitude’ we mean the film’s ability to capture detail in the highlights as well as the shadows of that scene without either ‘burning out the highlights to pure white and the reverse i.e. blocking up the shadows into pure black. Typically, print film has a latitude of 5-6 stops whilst transparency film is even smaller at >< 3-4 stops in real terms. (There are those who would quote differing figures but these are the generally accepted values). Over time film evolved and the camera hardware got more technical to deal with the situation (check out ‘pin-registration’ on 35mm SLR’s) and then… …along came Digital photography! But, the problem of latitude limitation remained - despite the technology leaps and bounds. The CCD and CMOS sensors used in the modern top-flight dSLR’s have latitude constraints that are very close to that experienced by transparency film users. That said, things have taken a big step forward with the release of the Nikon D3, D300 and D700 dSLR’s with their all-new 14-bit algorithms (as opposed to the standard 12-bit software) – but the problem of limited latitude still remains as a major challenge to the photographer looking to deliver the utmost quality of work when shooting high-contrast situations. This brings me neatly onto High Dynamic Range imagery (‘HDR’). ‘HDR’ is a way of significantly expanding the dynamic range (or latitude) of an image and has become very popular over recent times especially with the advent of many newer, less expensive programs attempting to emulate the market-leader ‘Photmatix’. To work effectively, HDR software needs a minimum of three separate images (preferably five or more) covering exposure values (‘EV’) 2 stops above and 2 stops below the recorded exposure for that high-contrast scene. This give the software between 12 and 20 stops of latitude to work with (4 stops/frame remember). Additionally, a tripod – or some form of firm support – is also needed to overcome any frame registration issues. But this is not the only way to expand the dynamic range in an image. Adobe Photoshop has always had the ability to bring multiple images together in different Layers and so produce a finished image with huge dynamic range. But – this is only possible on *processed* RAW files i.e. TIFF’s etc which, due to the processing, will have lost some of the original data no matter how careful one is in using non-destructive post-production techniques. So… what if we were able to combine multiple-exposed versions of a high-contrast subject – using the RAW files! (The Holy Grail – perhaps?) Well…? Now we can. Adobe Lightroom v2 has a new third-party plugin which will do just that – combine multiple-exposed versions of a high-contrast subject – using the RAW files exposed in the same manner as if we were going to use an HDR package. The product is called ‘Enfuse’ and full details can be found at http://www.timothyarmes.com/lrenfuse.php. I will leave you to read through Timothy’s site to understand more. Please note that the software is 'Donate-Ware' - so do please contribute as this will allow Tim to continue improving this excellent product. Working with RAW files makes an enormous difference – for obvious reasons but what impresses me most is the inherent natural look that the finished images have without that (sometimes) slight over-saturation that Photomatix files have – despite how careful one is to control it. (I am not a lover of those *awful* ‘offerings’ that appear from Photomatix which are supposedly ‘HDR’ images). Lets have a look at Enfuse: This image shows the original 5 Nikon NEF (RAW) files ready to be ‘Enfused’ in Lightroom v2 – Notice the spread of EV’s and in the left window the lightest version of the 5 files. Once the process has run in Lightroom, the file is exported as a 16-bit TIFF. It’s then re-imported back into Lightroom for finishing and the finished result becomes – Just for comparison, here are the same 5 files processed through Photomatix – Quite remarkable differences – across the board – not least of which is the time-line needed to achieve it. Using Enfuse takes a fraction of the time by any other method – and that is vitally important to a professional photographers workflow. If you are into HDR photography where the image must look natural, then I would encourage you to try Enfuse. And if you haven’t tried Lightroom v2 yet. Well…!! © Mike Otley Photography 2008 www.mophotos.co.uk