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HDR with SX10is

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HDR with SX10is
« on: 17 / July / 2009, 12:59:32 »
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HDR is far above my head. I'm new to this hobby, but I do enjoy looking at the HDR images. I don't plan on tackling HDR just yet, but I am curious about a few things. So CHDK gives me a few different ways of bracketing for HDR. By either changing shutter speed, or by changing f stop. Here's my question, how does bracketing by shutter speed work? When using a long shutter speed, my camera isn't capable of taking shots in rapid succession. Longer shutter speeds seem to take longer for it to save. So can the SX10is only bracket with aperture? Would a faster SD card significantly improved the amount of time the camera spends saving at longer shutter speeds?

One more question... Some articles about HDR say it's good for landscapes or anything where the subject isn't moving. Which makes sense since you'll aimed at the subject for an expended period of time, any movement would obviously be bad. But I've seen several HDR photos taken of people, or even faster moving subjects like vehicles or even fireworks. How is that done?

Thanks guys.

Re: HDR with SX10is
« Reply #1 on: 17 / July / 2009, 16:31:49 »
When using a long shutter speed, my camera isn't capable of taking shots in rapid succession.

Well, in continuous-shooting mode it will save them as fast as it can.
Low-level formatting a high-speed card (such as SanDisk Extreme III) helps speed things up.
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can the SX10is only bracket with aperture?
You do not normally aperture bracket for HDR.
It has a limited range and affects depth-of-field.

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Some articles about HDR say it's good for landscapes or anything where the subject isn't moving.
Easier said than done.
Foliage and grass is constantly moving in the slightest breeze.
Even though commercial programmes try to align such images they cannot do it perfectly and its leads to a loss of sharpness.

Re: HDR with SX10is
« Reply #2 on: 17 / July / 2009, 22:29:13 »
Easier said than done.
Foliage and grass is constantly moving in the slightest breeze.
Even though commercial programmes try to align such images they cannot do it perfectly and its leads to a loss of sharpness.

Ok, then my question remains. How are people getting such sharp HDR images of things like people and landscapes? I'm sure you've seen the portrait of the young Amish boy? It's a close up of just his face. I don't see how the photographer (Trey Ratcliff) managed to get such a sharp picture of a person. How would you get him to hold still while multiple shots were taken at varying shutter speeds?

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Offline PhyrePhoX

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Re: HDR with SX10is
« Reply #3 on: 17 / July / 2009, 22:35:00 »
you can do hdr from just ONE raw image. though some ignorant people may say that raw files from chdk arent of any use, you can use them for example for hdr.

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Offline Anaglyphic

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Re: HDR with SX10is
« Reply #4 on: 17 / July / 2009, 23:46:48 »
hi nitsuj,

Think about it. A normal JPEG is made up of 3 x 8-bit ranges of brightness for R/G/B, respectively. That's 256 levels for each color. Now toss in RAW format. Even CHDK's "lowly" 10-bit RAW changes that to 1024 levels of brightness, per color. (reinforcing what Phyre said). A nice dSLR shoots in 14-bit RAW, giving you 16,384 levels.

You can make many exposures from a 14-bit RAW image, which makes creating "action" HDRs easy as taking a single picture.

Try some basics, before getting down to logistics. One nice HDR introduction tutorial is Sean McHugh's HIGH DYNAMIC RANGE PHOTOGRAPHY article. Give it a read, I'm sure you'll learn a thing or two.
Since we cannot know all that there is to be known about anything,
 we ought to know a little about everything.
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Re: HDR with SX10is
« Reply #5 on: 18 / July / 2009, 03:21:29 »
This is treys tutorial on how to do HDR: http://www.stuckincustoms.com/hdr-tutorial/

I may experiment with this in the next couple of days. I've been wanting to try HDR for sometime.

Re: HDR with SX10is
« Reply #6 on: 18 / July / 2009, 14:37:11 »
Here is a quick HDR single image test using my SX10.

Before:


Larger view: HDR Test: Before

After (HDR):


Larger view: HDR Test: After

It's a bit overexposed, so I need more tweaking. I used -3.0, -1.5, 0, 1.5 and 3.0 exposures.

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Offline fvdk

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Re: HDR with SX10is
« Reply #7 on: 18 / July / 2009, 16:44:17 »
Here is a quick HDR single image test using my SX10.

Before:


Larger view: HDR Test: Before

After (HDR):


Larger view: HDR Test: After

It's a bit overexposed, so I need more tweaking. I used -3.0, -1.5, 0, 1.5 and 3.0 exposures.

I'm not sure what you are trying to accomplish but isn't it something that can be done by just tweaking it in a photo editing program?

Here it is tweaked a bit in Lightroom.



Let me know if you want me to delete the picture.

Frans

Re: HDR with SX10is
« Reply #8 on: 18 / July / 2009, 21:52:49 »
It probably can be tweaked just a bit. I didn't have much time to play with settings to get it just right, it was just a test to see if doing HDR with a single raw is simple (and it is).

You can keep the tweaked photo up.

 

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