louis

08 Aug 2007 843 views
 
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photoblog image Dynamic ranges 2

Dynamic ranges 2

A colleague of mine suggested this posting to explain a bit better about the increasing the dynamic range in the camera through processing. First what one should anderstand is that the range of colours in a camera is limted and departs from the white and black points. That is why your camera manufacturer sometimes recommend custom setting of the white balance - to obtain truer colours. Improved software in more expensive cameras has a larger dynamic range. The effect of the increased range you can see in the modern TV cameras - e.g. the opening shots of Miami Vice etc.

My camera has a bracketing function as I have explained yesterday. I set it to bracket by two f-stops. The shot at bottom left is the standard shot as it would have appeared at automatic. The bottom middle is two stops lower and the right bottom is the two stops higher.

I load all three shots and start with the HDR mapping exercise in the software, followed by adjusting the tonemapping settings to suit taste. In my case I try to get the picture as real as I remember it. The HDR exercise means that the software goes through some algorhytms to determine best representation. The software can reproduce at a greater Dynamic Range of colours.

The picture at the top is the final product from the HDR mapping exercise.

The ideal situation for HDR fiddling would be a late afternoon (or early morning) with a sky full of clouds and some detail in the foreground. The foreground in these kind of shots normally turns out dark and you loose detail. The bracketed shots provide each in its own way more detail of the fore-, middleground and the skies. In the process you can profit from a larger range of colours.

This picture was taken during the weekend at Dullstroom where we did the endurance ride. Very hilly country and cold at nights. The hills and stones produced a ride of a very high grade of difficulty.

Dynamic ranges 2

A colleague of mine suggested this posting to explain a bit better about the increasing the dynamic range in the camera through processing. First what one should anderstand is that the range of colours in a camera is limted and departs from the white and black points. That is why your camera manufacturer sometimes recommend custom setting of the white balance - to obtain truer colours. Improved software in more expensive cameras has a larger dynamic range. The effect of the increased range you can see in the modern TV cameras - e.g. the opening shots of Miami Vice etc.

My camera has a bracketing function as I have explained yesterday. I set it to bracket by two f-stops. The shot at bottom left is the standard shot as it would have appeared at automatic. The bottom middle is two stops lower and the right bottom is the two stops higher.

I load all three shots and start with the HDR mapping exercise in the software, followed by adjusting the tonemapping settings to suit taste. In my case I try to get the picture as real as I remember it. The HDR exercise means that the software goes through some algorhytms to determine best representation. The software can reproduce at a greater Dynamic Range of colours.

The picture at the top is the final product from the HDR mapping exercise.

The ideal situation for HDR fiddling would be a late afternoon (or early morning) with a sky full of clouds and some detail in the foreground. The foreground in these kind of shots normally turns out dark and you loose detail. The bracketed shots provide each in its own way more detail of the fore-, middleground and the skies. In the process you can profit from a larger range of colours.

This picture was taken during the weekend at Dullstroom where we did the endurance ride. Very hilly country and cold at nights. The hills and stones produced a ride of a very high grade of difficulty.

comments (13)

Thanks for sharing this example. Why did the sky turn so yellow. It that a result of the HDR process or a result of an adjustment you made?
Louis: The short answer is that it is the result of the HDR process.
The longer answer is that the process includes tonal adjustment. The golden (or yellow colour) was in the sky at the time of the shoot, so it is realistic. After the HDR merge the golden colour was immediately visible. If you take a close look at the two bottom left pictures you will see a hint of the yellow/golden colour. I think the top picture (final result) doesn't do the picture justice as it is too small in the post. I will post it on its own at some stage - maybe the weekend when I normally don't blog.
Thank you for your comment and interest Martin.
Cool :S
Louis: Thank you Suby & Sinem
  • Kay
  • 8 Aug 2007, 02:20
Louis, I can learn a lot from you. I like the final result. wink
Louis: Thanks for the comment Kay. Some of these things happens as my fancy swings. Since many people were going on about HDR I started to read up, amongst them the camera's manual and then looked what I have in my processing software. And I am off on a mission. I can't wait for our summer when we will have dark afternoons with dramatic clouds etc.
Anyway, thanks for your comment Kay.
  • GL@
  • Netherlands
  • 8 Aug 2007, 06:54
4 voor de prijs van 1. Te gek!
Louis: Ja lieferd, nu hang je weer helemaal de hollander uit wanneer daar een voordeelkoopje op zicht is. Liefde aan allemaal tuis. Jij moet ook een keer naar de fotos van http://peet.shutterchance.com gaan kijken - dat is ook van een bekende.
Martin said what I wanted to say :d
Louis: In that case, here is my reply to Martin:
The short answer is that it is the result of the HDR process.
The longer answer is that the process includes tonal adjustment. The golden (or yellow colour) was in the sky at the time of the shoot, so it is realistic. After the HDR merge the golden colour was immediately visible. If you take a close look at the two bottom left pictures you will see a hint of the yellow/golden colour. I think the top picture (final result) doesn't do the picture justice as it is too small in the post. I will post it on its own at some stage - maybe the weekend when I normally don't blog.

Thank you for your comment and interest Chacha.
A perfect explanation of the process and good examples of it. Good work, Louis! smile
Louis: Thanks for the comment and interest José-Angel
Very nicely done Louis... Did you upgrade from the 350d to the 400d ? Is it worth while ? Thanx !
Louis: In the olden days I have been using film with a Cosina and a Pentax. Then lost interest in photography around 1998. Got hold of a Olympus C765UZ (after I got relieved of a C720UZ) and then the bug bit. One of my problems was that the instamatics are too slow when I do bird pictures. Then got the 400D. But I know the 350D fairly well from close people who has it. If you currently have a 350D I would not recommend an upgrade to 400D. In capability the 2 are far too close. If you want to upgrade, rather go for the 20D, 30D, 5D or if you have money to burn the 1Ds mark II.
If you want more information on the models mentioned and even to do compares, go to http://www.wholesaledigital.co.za/canon.htm

Thanks for your comment Ferdi.
  • Ginnie
  • Atlanta, GA, United States
  • 8 Aug 2007, 13:49
This is probably the best tutorial I've read to date, Louis, of HDR processing. I actually think I have a bracketing function on my wee camera so maybe some day I will actually try this. Thanks for the time and effort you took to explain this process!

I'm sending this to my Likeys so that I can refer to it in the future! smile
Louis: I must say I am surprised by the interest that this blog provoked. It is not even a great picture and the main picture of the group is too small to really see the impact of the conversion, although it does give an idea. So - i never thought it would land in a likey, for whatever reason and feel honoured. Thanks Ginnie.
This is the colleague who made the 4 pic suggestion... I like the fact that I can now see what you worked with and compare that to your result. It's a pity though that it makes the main pic smaller, as yesterday's pic was a better size to look at. I agree that this technique will only come to it's full potential during our spring/summer with teh clouds late afternoon. Should produce some really WOW pics. Can't wait for you to do those. Also try the tripod and see if it makes a difference with the alignment?
Louis: Thank you Johan - like they say: Watch the space as the seasons change. I am wiping the dust from the tripod as well.
  • mal
  • 8 Aug 2007, 21:17
i've been meaning to try this for ages Louis! I shall be picking your brains for tips shortly! Love the final image. mal
Louis: Thanks mal - I will post the final image for Saturday fo those who are interested.
How many years will it take for me to be thinking like this....quite a few, I think. (at least now I know what the bracketing feature on my camera does.) (:o)
Louis: Its mostly a case of opportunity that crosses my pah that set me off on these directions. Thanks for the comment Rosalyn.
Good explanation and nice example pictures to go along with it. Do you or have you ever considered teaching a course where you live? If someone had one here I would sure jump at the chance of attending.
Louis: Thanks for the comment DD. I don't believe I am good enough to teach beyond a basics course. My approach is that I try stuff and if it works, I share.
Here in SA are a number of camera clubs - in cities more than one as well. Mostly affiliated with the SA Photographic Society. They organise courses, have club meets with speakers and arrange courses. Also they teach you they correct rules etc for presenting pictures in the different competition categories. I dunno how things are organised where you live, but it should be pretty much the same. So that is my recommendation that you join a club in your area and take it from there. Just check out the club's manifest to make sure it is a good club.
  • Gale
  • Cape of Storms
  • 12 Aug 2007, 16:05
Hi Louis .. very interesting technique indeed. What software do you use. Regards Gale?
Louis: Two types of software. I have PS CS2 and with the software comes a tutorial of how to go about it. A bit round-and-about method. Much easier and specialised software is Photomatix (just google the name) and I am satisfied with the results.

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