HDRI and80MP photos from a 8mp Camera

[Case]

Had a guest speaker recently in one of my classes and essentially soon as finals are over (2 weeks) I will be posting examples and a simple How To: on how to build HDRI images in photoshop and create 100mb+ raw image from a simple 8mp camera.
All you really need is a decent camera and a good tripod that is key! The camera has to be capable of full MANUAL mode you never EVER trust auto anything and all ways manual focus.

What is HDR you say?
HDR/High Dynamic Range or HDRI/High dynamic Range imaging is a set of techniques that allow a far greater dynamic range of exposures (IE a large difference between light and dark areas) than normal digital imaging techniques or cameras even have the ability to do with just one photo. HDRI was originally developed to use these images in 3d like 3d Studio max or Maya. We end up using the range of light in the image to produce ultra realistic lighting in 3d.

For example: http://indyzone.jp/catalog/products/evermotion/img/ai05_003.jpg
HDRI photos can look all most unreal because they look so like what we see with our own eyes its not what we are use to.

http://www.vividaspect.com/pix/BestOf/LakeMinnewanka20051125_EOS10D_2/JohnsonLake_SZ24_0014_TM_NSN.jpg
This photo is a low res image of a high res HDRI photo and were the darkest parts are there’s tons of detail what would normally be black and lacking detail and the brightest white parts on the ice again what would lack detail in fact has detail.

http://www.cambridgeincolour.com/tutorials/graphics/tut_hdr_door-brightdist.jpg http://www.cambridgeincolour.com/tutorials/graphics/tut_hdr_door-lowexp.jpg http://www.cambridgeincolour.com/tutorials/graphics/tut_hdr_door-hiexp.jpg

This image shows (left to right) How light falls in the image that one area is dark one is very bright. If you underexpose you get nice detail outside while you over expose you get nice detail inside but you sacrifice one part or another of the photo there is no middle ground.

The final result of a HDR image looks like this:

http://www.cambridgeincolour.com/tutorials/graphics/tut_hdr_finalimage.jpg

as you can see you loose no detail and every thing is properly exposed as it would be to our human eye. To a camera in this situation just wont be able to see the dynamic range of light and you will loose the detail.

Another quick example

http://www.cambridgeincolour.com/graphics/workflow_dr_ex1a.jpg
Under Exposed

http://www.cambridgeincolour.com/graphics/workflow_dr_ex1b.jpg
Over Exposed

http://www.cambridgeincolour.com/graphics/workflow_dr_ex2b.jpg
Final Composite that violates the tonal hierarchy that you would typically see


More to come soon

[Case]

BTW you can view HDR images on Flickr theres a HDR group here (http://www.flickr.com/groups/hdr/)

this is one of my fav photos http://flickr.com/photos/bcnbits/331201743/ GREAT example of HDR imaging

[keith]

That's a very good "tutorial" on camera lighting effects.

[Case]

Its not really a effect.. Essentially what your doing is taking various photos of the same image some cameras can automate this with a feature called bracketing. But prosumer DSLR's can only do 3 photos while the pro digitals will do up to 9 so you will be required to do it by hand on Prosumer DSLR's or lower..

Once you have those images you end up taking the data from each image to compress it into one image thats a HDR image. So its not a filter or effect its just a different processes to take a picture to produce a image that has a much larger range of light than typically seen in photography.


Typical outdoor, sunlit scene - 100,000:1 or more Dynamic Light range - ~17 EV Stops
The Human eye - 10,000:1 - ~14 EV

- Here is were the major change starts -

Film camera - up to ~2000:1 ~11 EV
Digital camera - typically ~400:1 ~8.5 EV
Good computer monitor - 500:1 to 1000:1 9 - 10 EV
Typical photo print - 100:1 up to 250:1 7 - 8 EV

a HDR image will have a dynamic light range far higher than a Normal digital print giving the photo far far more detail.

I can only dream that one day cameras will have this built in and automate the processes completely like a HDR Digital camera but thats far off :)

Ill post a actual tutorial soon

there is a neat HDR Gallery here http://www.pbase.com/michaelsv/hdr

http://www.pbase.com/michaelsv/image/68108802 Detail in that water is amazing