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DPChallenge Forums >> Tips, Tricks, and Q&A >> My first attempt at Dynamic Range Increase
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 07/29/2006 05:39:40 PM · #1
Well, today I experimented a bit with Dynamic Range Increase (I think it's also called HDR). I used this image to start with:

This was taken using only window light, therefore the head is a bit overexposed on one side, and a bit underexposed on the other side. I also opened the image in Photoshop with one stop underexposure

and one stop overexposure


I then combined the three images using the technique described here by A. Tofahrn, resulting in this image:



I must say I'm impressed with the result, although this particular image is more interesting with the contrast as in the first image. It would probably work best for night shots such as city scapes with lots of lights. I was also amazed that the technique is much, much easier to use than I feared. Give it a try too!

Oh, and don't mind the noise, that's another project I still have to figure out how to use correctly.

Message edited by author 2006-07-29 17:42:38.
 07/30/2006 08:21:43 AM · #2
bump
 07/30/2006 08:43:17 AM · #3
Nice job, but I will say it is a pretty subtle difference though. for a more strikign picture i'd reccomend going two stops over and under instead of just one like I did with this picture.




and the result:
07/31/2006 03:41:30 AM · #4
Now if only any of this were legal for DPC.. :(
 07/31/2006 03:48:17 AM · #5
Originally posted by lament:
Now if only any of this were legal for DPC.. :(


It IS legal for advanced editing if you shoot in RAW and make your overs and unders off the original exposure.

R.
 07/31/2006 12:23:44 PM · #6
True, but that doesn't count, does it -- I thought the whole point of HDR (or fake HDR, as it might be) was overcoming the limited dynamic range of the camera itself, requiring more information than available from a single capture...
 07/31/2006 01:20:59 PM · #7
Originally posted by lament:
True, but that doesn't count, does it -- I thought the whole point of HDR (or fake HDR, as it might be) was overcoming the limited dynamic range of the camera itself, requiring more information than available from a single capture...


This is true, as far as it goes, but a correctly exposed RAW capture has usable data that can be mined at both ends of the histogram. In extreme situations, you need more than one actual exposure, but nevertheless you can significantly improve many photographs by using the "multiple RAW" merging process.

R.
 11/13/2006 05:55:35 PM · #8
I must be doing something wrong...

I have tried using the HDR function in Photoshop CS2, but it always tells me there is not enough dynamic range in my files to complete an HDR image.
I have tried taking a RAW exposure and creating separate images up to +3 stops and -3 stops. I have also shot images on a tripod, -2 stops to +1 stop. I always get the same message...

Am I missing something, or do I need to reinstall Photoshop?

Thanks,
JD
 11/13/2006 06:08:41 PM · #9
Originally posted by smellyfish1002:
I must be doing something wrong...

I have tried using the HDR function in Photoshop CS2, but it always tells me there is not enough dynamic range in my files to complete an HDR image.
I have tried taking a RAW exposure and creating separate images up to +3 stops and -3 stops. I have also shot images on a tripod, -2 stops to +1 stop. I always get the same message...

Am I missing something, or do I need to reinstall Photoshop?

Thanks,
JD


I know you cant do it with the same image processed differently in Raw. CS2 uses Exif data to determine weather the dynamic range is different enough to do it. I'm not sure about what you have done on the tripods, maybe after exif it looks at differences between shadows and highlights in the histograms.

MattO
 11/13/2006 06:16:45 PM · #10
Just my opinion, but HDR should be used to reveal details at the extremes of the histogram while leaving the bulk of the histogram unaltered. You should still have 'black' data and 'white' data if that data was included in the original. But the subtle details that usually get lost in the shadow or in the bright areas can be recovered to enhance the photograph.
When carefully done, the result can be a very pleasing photograph with good contrast and little in the way of blown highlights or detail buried in shadow. If the original was properly exposed then all the detail present in that original can be recovered by manipulation of 'curves' and 'levels'. Multiple exposures (obviuosly) can extend the range beyond that available from a single exposure, but there are few circumstances when that range is useful or even desireable.
 11/14/2006 10:47:12 AM · #11
I will try saving different 'exposures' from the RAW file using the 'Save for Web' function. That should strip the EXIF.
I'll see what happens...
JD

Originally posted by MattO:
Originally posted by smellyfish1002:
I must be doing something wrong...

I have tried using the HDR function in Photoshop CS2, but it always tells me there is not enough dynamic range in my files to complete an HDR image.
I have tried taking a RAW exposure and creating separate images up to +3 stops and -3 stops. I have also shot images on a tripod, -2 stops to +1 stop. I always get the same message...

Am I missing something, or do I need to reinstall Photoshop?

Thanks,
JD


I know you cant do it with the same image processed differently in Raw. CS2 uses Exif data to determine weather the dynamic range is different enough to do it. I'm not sure about what you have done on the tripods, maybe after exif it looks at differences between shadows and highlights in the histograms.

MattO

11/14/2006 11:41:44 AM · #12
Originally posted by ElGordo:
Multiple exposures (obviuosly) can extend the range beyond that available from a single exposure, but there are few circumstances when that range is useful or even desireable.


Unless you're a landscape photographer, when you have to deal with extreme tonal ranges all the time. Even if full HDRI is not "needed", tone mapping is a godsend for landscape shooters. And bear in mind that even if the range is only slightly out of gamut, if you do multiple exposures (even from one RAW file) you can get nice, subtle results that are significantly better on the real world than what you get from curves. You can't see the difference so much at 640 pixels, but you sure as hell can at 20x30 inches, where the HDRI image has MUCH better local contrast in the dark areas, allowing you to LEAVE them darker and still see pleasing detail; so the overall tonalities of the print are much more effective.

R.
 11/14/2006 01:11:40 PM · #13
Or you could buy a Fuji S3 or S5 and you never need HDR anymore. The dynamic range you can pull from a raw file from that camera is amazing.
I hope the S5 is any decent (D200 body) and not too expensive.


11/15/2006 11:03:35 AM · #14
Originally posted by Bear_Music:
Originally posted by lament:
True, but that doesn't count, does it -- I thought the whole point of HDR (or fake HDR, as it might be) was overcoming the limited dynamic range of the camera itself, requiring more information than available from a single capture...


This is true, as far as it goes, but a correctly exposed RAW capture has usable data that can be mined at both ends of the histogram. In extreme situations, you need more than one actual exposure, but nevertheless you can significantly improve many photographs by using the "multiple RAW" merging process.

R.

Is the multiple JPG from one RAW technique any better than converting RAW to a 16 bit TIFF?
11/15/2006 11:08:24 AM · #15
Originally posted by Bear_Music:
Originally posted by ElGordo:
Multiple exposures (obviuosly) can extend the range beyond that available from a single exposure, but there are few circumstances when that range is useful or even desireable.


Unless you're a landscape photographer, when you have to deal with extreme tonal ranges all the time. Even if full HDRI is not "needed", tone mapping is a godsend for landscape shooters. And bear in mind that even if the range is only slightly out of gamut, if you do multiple exposures (even from one RAW file) you can get nice, subtle results that are significantly better on the real world than what you get from curves. You can't see the difference so much at 640 pixels, but you sure as hell can at 20x30 inches, where the HDRI image has MUCH better local contrast in the dark areas, allowing you to LEAVE them darker and still see pleasing detail; so the overall tonalities of the print are much more effective.

R.

Hi Robert,

There are some controls in RawShooter Premium that alow you to change the contrast of shadows and highlights, and I'm wondering if the result can be similar to the multiple exposure from one RAW file results. Or to ask a more general question, can some RAW conversion program do the tone mapping so you can eliminate the multiple exposure step?

(I assume lightroom has similar controls to RSP, but haven't played around with it enough to know for sure).
 11/15/2006 11:23:19 AM · #16
Photomatix (the newest build) allows you to drag a RAW file into the work area where it automatically produces 3 exposures and composes them... very tasty bit of software..
 11/15/2006 11:50:48 AM · #17
Originally posted by marksimms:
Photomatix (the newest build) allows you to drag a RAW file into the work area where it automatically produces 3 exposures and composes them... very tasty bit of software..


really? i own Photomatix and never knew that! can you elaborate more on how its done?
 11/15/2006 11:52:13 AM · #18
Originally posted by marksimms:
Photomatix (the newest build) allows you to drag a RAW file into the work area where it automatically produces 3 exposures and composes them... very tasty bit of software..


Great tip, thanks for that.
 11/16/2006 07:30:26 AM · #19
Originally posted by noisemaker:
Originally posted by marksimms:
Photomatix (the newest build) allows you to drag a RAW file into the work area where it automatically produces 3 exposures and composes them... very tasty bit of software..


really? i own Photomatix and never knew that! can you elaborate more on how its done?


Just make both the folder with the RAW and photomatix visible on the screen. Grab hold of the RAW file and drag it across to the work area of photomatix. The rest is automatic. It saves having to create 3 JPGs to work from, and one would assume that you dont have to deal with the compression issues as well.

Remember though, you get best results by using 3 properly bracketed images instead of just 1 split into 3 psuedo bracketed images.

Maybe when I get home I will show two examples, one where I use 3 images, and one where I drag just a single raw across to see what the difference is.
 11/16/2006 07:50:00 AM · #20
On a Mac, you can just drag the RAW file to the Photomatix dock icon. I found that out while trying Mark's tip.
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