HDR from a single image or many???

jammy_c

jammy_c

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With the search function down at the moment I’m not sure if this subject has been covered a dozen times already, but I thought I’d ask anyway.

I know that you can produce a HDR image either from a single RAW file, adjusting EV and creating copies to “stack/tonemap” but how does it compare to doing it “by-the-book” with 3, 4, 5, or more RAWS taken over a short period of time with differing stops of exposure?

If my camera was to have an “auto-bracketing” function then it’d be a no-brainer, but if you set out to do landscapes or architecture for example, is it worth carrying a tripod for day-time HDR source shots, or are you just as well taking a single RAW and adjusting EV afterwards?

I created a HDR image of the O2 Arena that I’m really pleased with, using a single RAW as the boat I was travelling on passed by. But I just wondered, given the time. could it have been improved by using several shots?
Discuss please……:)

(I don’t think I can post the image in question as it is entered into the Sept TP competition. I think I can link ***……right mods?) :shrug:


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I think with a moving subject you need one raw image only as obviously movement will cause ghosting if you take multiple shots.
Another thing to consider is that if there are a lot of dark shadows and/or bright areas, (ie a large dynamic range) then multiple exposures works best.
If you just want to bring out some detail in shadow areas then a single image should be ok.

Thats how I understand it anyway :)
 
If you can capture the full dynamic range in a single exposure then it's not really a scene that contains a high dynamic range in the first place.

The number of exposures you need depends on the scene. Three exposures on 2-stop intervals will give a good dynamic range to process and tonemap. Four exposures over 2-stop intervals are even better.. get down to 1-stop intervals and seven or eight exposures and you're really cooking on gas.

There is an unwritten assumption that you need an odd number of exposures for HDR.. this in't the case.. you just need as many as you need to capture the full dynamic range. It gets easier to figure out when you realise that you don't need to base your exposures around a nominal zero exposure.
 
cool, cheers guys. a couple of good things to consider. I'll keep playing with it and see how I get on. :)
 
Oloneo make a good program (which is free at the moment) which allows you to create an HDR image from a single shot.

I've tried it and it gives very good, very fast, results.

.
 
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petersmart said:
Oloneo make a good program (which is free at the moment) which allows you to create an HDR image from a single shot.

I've tried it and it gives very good, very fast, results.

.
Click to expand...

Cheers, I'll have to try that. Any examples you can share?
 
petersmart said:
Oloneo make a good program (which is free at the moment) which allows you to create an HDR image from a single shot.

I've tried it and it gives very good, very fast, results.

.
Click to expand...

Having tried Oloneo and Photomatix with both a single and multiple images, I am only finding two differences - Oleneo appears easiers/quicker to use and is currently free.
Can any explain why to opt for Photomatix over Oleneo?:thinking:
 
Just downloaded Oleneo and had a quick play and it looks good. Much faster than Photomatix.

The only thing that it does not appear to do that Photomatix does is eliminate ghosting where elements in the different exposures have moved between exposures. It does align the frames well where the frames do not line up due to hand holding instead of a tripod, though

An example of eliminating ghosting in Photomatix. All these people were moving and the camera was hand held. Three exposures.


Bath street scene by jomike, on Flickr
 
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looks good. is the download the full program or just a trial?
 
Hello, sorry to change the topic of the thread.....slightly....but I have taken some photos for HDR, put them through Photomatix but I cant seem to save them anywhere....I click on file...save as.....save it to the folder I want but then when I go in to that folder I cant open them up!?!?!

Probably a very simple answer to this but I'm new to photography.

Hope you can help me...

Tom
 
CATALOGUEKID said:
Hello, sorry to change the topic of the thread.....slightly....but I have taken some photos for HDR, put them through Photomatix but I cant seem to save them anywhere....I click on file...save as.....save it to the folder I want but then when I go in to that folder I cant open them up!?!?!

Probably a very simple answer to this but I'm new to photography.

Hope you can help me...

Tom
Click to expand...

Are you saving it as a .jpg ?
 
photomatix will save the HDR image as well (32 bit) it's not that your trying to open by any chance is it? rather than the finished tonemapped image.

Edit why am I getting stupid green links all of a sudden?
 
jammy_c said:
Are you saving it as a .jpg ?
Click to expand...

Is it best to save them as .jpg? just want to save them somewhere in the best format for uploading on to here and for printing off.

cheers.

Also, when I usb my camera to my laptop to downlaod pictures....when I open up my camera to view the pics all the thumbnails are blank so I cant view them...I take my pics in RAW so how can I view my thumbnails so I can edit them!?!?!
 
One way to view your raw if you haven't got bridge is Faststone image viewer, it's a free download and works pretty well (I don't use it but have mates who do) lots of people on the forum use it as an image browser I believe.
Another free viewer is Picassa (part of google) thats another free download raw viewer, that has basic ajustments as well, I have used this in the past, the first time you run it does a search for your pics and organise them (without moving them) into folders for easy viewing.
 
:agree::plusone:For Picasa! I use it all the time,

you can't view the RAW thumbnails in windows explorer because windows (assuming you are using a PC, not MAC) doesn't recognise RAW/NEF as image files, just data.
Picasa will let you see the RAW as a thumbnail, but i don't know what it's like as an editing tool. I always use the Nikon software (ViewNX) to edit RAW. Did you get editing software with the camera? either way, it's difficult viewing the thumbnails before converting to .jpg/etc... you might find it easier to adjust the whole batch and save them as .jpg, then keep the RAWs in a subfolder, so you can always come back to them if needs be. That always seems to work well for me, you can use the .jpg thumbnail filenames as a reference then.
 
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jammy_c said:
:agree::plusone:For Picasa! I use it all the time,

you can't view the RAW thumbnails in windows explorer because windows (assuming you are using a PC, not MAC) doesn't recognise RAW/NEF as image files, just data.
Picasa will let you see the RAW as a thumbnail, but i don't know what it's like as an editing tool. I always use the Nikon software (ViewNX) to edit RAW. Did you get editing software with the camera? either way, it's difficult viewing the thumbnails before converting to .jpg/etc... you might find it easier to adjust the whole batch and save them as .jpg, then keep the RAWs in a subfolder, so you can always come back to them if needs be. That always seems to work well for me, you can use the .jpg thumbnail filenames as a reference then.
Click to expand...

It is limited but will do the basic ajustment, but no match for "proper" editing software.
 
I thought if you used a single file to produce an HDR image it was actually simulated HDR. Surely the whole idea of HDR is you are trying to create an image containing a greater dynamic range than your camera is capable of capturing in a single shot. This is why you need multiple exposures which you then combine. If it's made from one shot then it cannot be HDR.
 
me15 said:
I thought if you used a single file to produce an HDR image it was actually simulated HDR. Surely the whole idea of HDR is you are trying to create an image containing a greater dynamic range than your camera is capable of capturing in a single shot. This is why you need multiple exposures which you then combine. If it's made from one shot then it cannot be HDR.
Click to expand...

Yes and no, your right that is the idea of "true" HDR, but by making 3 different exposures from a single raw you are extending the dynamic range of the single shot (sort of) but more importantly not all HDR images that people see actually have an extended dynamic range, it's the "look" that some people like, combining 3 or more shots doesn't mean you always have a wider dynamic range. It all depends on the tonal range of the scene ypur photographing.
 
HDR, to me anyway, is any photograph that contains a greater dynamic range than can be captured and displayed with a single shot. So in other words, it dosen't matter to me whether it's one shot or several, if you are combining exposures and displaying them combined then that is a HDR shot. What people forget is that a single RAW file contains more information than can be displayed on screen at any one time. It's just teasing that information out and tone-mapping it to give a final image. I have lots of experience with HDR and i find that splitting a single raw gives exactly the same result as taking three or five shots, as long as the original shot "the 0" is exposed correctly and the lighting conditions are not too extreme.

So yes, 99% of the time one RAW is enough to give a good HDR image, and it's essential for moving subjects unless you want to spend lots of time in photoshop with layer masks to fix all the ghosting artifacts.
 
Ok, so I downloaded Oloneo last week and had a play over the weekend.
Let me know your thoughts. all of these were created from single .JPGs

1.
66583_134993889883450_134991203217052_183285_1282259_n.jpg



2.
68024_134993946550111_134991203217052_183286_597909_n.jpg



3.
69189_134993979883441_134991203217052_183287_7739846_n.jpg



4.
69411_134994249883414_134991203217052_183292_5033168_n.jpg
 
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