HDR - what am I doing wrong?

Dear all,

I had the opportunity to take pictures inside a lovely historical Dutch house. A job that called for HDR, or so I thought. Because I can't seem to get the HDR right. I shot 3 exposures on my E-510 with the 12-60, + and -.3. First pic is the discouraging result from the HDR merger in CS3. I am clearly doing something wrong, but what? I pulled every slider I could find, to no resolve.

Second pic is the result of I got from raw-conversion and some pp, and which I am very pleased with.

Any hints, tips or pointers on how to improve on my HDR-abillities are very, very welcome.

Thanks in advance!

Robert

Result from HDR:



Result from Raw + PP

... to increase your bracketing value - from + -.3EV to + -1EV.

I don't think you're capturing enough dynamic range with + -.3 EV for the HDR software to do anything with.

Ralph

in the three exposures. Up or down .3 isn't going to increase your range of exposures very much for effective HDRor blended images. (Also make sure you are adjusting the shutter speed, not aperture)

On the E-510, shoot at + - 1.0. On the E-3, you can do up to 5 exposures and up to 1.0 between each shot on a single press of the shutter.

If you want to get a better idea of what this shot could have been, go back to your raw and output 3 exposures at -1, 0 and +1 and import them into a demo of Photomatix or blend them in Enfuse.

Hi Robert,

I'm not a regular HDR user, but I'd say there's a couple of things you could improve.

1) Use a larger bracketing range: I'd put 1EV or 2EV between every shot. 1/3 EV simply doesn't make a very big difference.

2) After creating a HDR image, it's still up to you to map the tones. If you don't, you'll end up with a grey-ish image like the one you posted.

There is a lot of confusion about the meaning of 'HDR'. Technically, it's just the capture of extra dynamic range through the merging of multiple exposures. The HDR image is then tone-mapped to an output medium/image that typically has a much lower dynamic range. To make use of the extra information in the HDR image, all sorts of algorithms are used to compress the high input dynamic range into a limited output range. This is what gives the 'HDR look', even though it's technically tone mapping. Photoshop doesn't offer much in terms of these types of tone mapping algorithms, so if you're after the HDR look, you'll have to do it manually (masking, etc) or get another program.

Hope this helps.

Simon

One thing to remember about the HDR imaging is that it is basically tone mapping as already stated here in earlier replies. Below is a bit theory to help you get you up to speed with the concept behind HDR...

If we take a hypothetical B/W camera with 8bit RAW (each pixel has values from 0 to 255). Now the scene you are shooting has luminosities which would correspond to values -200 to 450. As you can see that much of the image will be clipped to 0 on the dark end end to 255 on the bight end.

Now to make HDR you take a two additional images with offset by 50 luminosity units. You are then capturing the range of 0-50=-50 to 255+50=305. Better, but no cigar. If the images are offset by 200 units you get the whole image as you are capturing the range of -200 to 455.

However you still need to map the range of -200 to 450 to the output range of 0 to 255. This is not exactly simple task if you want to have a good image quality and it definitely needs some mathematical wizardry to make it happen.

PRACTICAL HINTS:

1)Take as many images as you can. It usually does not hurt the have an overabundance of data to work on.

2)Keep in mind is that in the most overexposed image of the HDR set you must have the darkest portions of the image exposed high (bright) enough so that you have the detail there and at the most underexposed image must conversely contain the brightest portions.

3)The HDR program your using should be up to the task. Photoshop isn't exactly stellar here. I myself like PhotoAcute, but that is a bit of personal taste...

plus flash. better results than hdr and easier t'boot.

--
Archer in Boulder

Thanks for the Dadaist pep talk. I feel much more abstract now.

i find photoshop not suited for HDR,try using Dynamic Photo HDR or Photomatix

The 2nd shot seems pretty damn good to me.

--



========================

When told the reason for Daylight Saving time the old Indian said... 'Only a white man would believe that you could cut a foot off the top of a blanket and sew it to the bottom of the blanket and have a longer blanket.'

dpalugyay said:

in the three exposures. Up or down .3 isn't going to increase your
range of exposures very much for effective HDRor blended images.
(Also make sure you are adjusting the shutter speed, not aperture)

On the E-510, shoot at + - 1.0. On the E-3, you can do up to 5
exposures and up to 1.0 between each shot on a single press of the
shutter.

Click to expand...

Note on the E-3 you can have 5 exposures with a maximum EV span of 2EV. Not meant for HDR...

Member said:

If you want to get a better idea of what this shot could have been,
go back to your raw and output 3 exposures at -1, 0 and +1 and import
them into a demo of Photomatix or blend them in Enfuse.

Click to expand...

--
Tim
'I haven't been everywhere, but it's on my list.'
E3/E410/7-14/12-60/50-200/25/EC-14
http://www.flickr.com/photos/timskis6/

Thanks everyone for your input. Maybe I was a bit naive to think I could go out and do a bit of HDR just like that. And RStacy, thanks for the compliment. Indeed I'm very happy with #2.

Robert

Just to add a bit - if this was your first attempt you picked an image that is very challenging even for hdr.

You probably have about 8-9 EV range in this photo with the darkest area (upper left corner of room) right next to the brightest area (window). This makes tone mapping a little more difficult.

You would probably need to shoot at least 9 images at 1 EV intervals to capture the entire dynamic range of this shot.

The quickest way to do that would be to spot meter the outside bright area, note the exposure and then do the same in the dark corner. Fill in the difference with evenly spaced shots by changing the shutter speed.

This would give you enough latitude to show the scene outside the window and in the darkest corner all evenly exposed.

HDR is sometimes a little hard to grasp right off the bat but once you do a little research, reading and playing your results will definitely improve.

There are some good tips and tricks on the photomatix site that are relevant no matter which hdr program you choose to use:

http://www.hdrsoft.com/support/faq_photomatix.html#tips

Gary

My E-3 has five exposures at 1 ev apart...does very nice HDR. I'm not sure you or I know what you are referring to.

Tripod 5 exposures 1 EV apart AE bracketed. This is an E-3, not a 1D, but still does a better job than half or better of the DSLRs available.

-2, -1, 0, +1, +2 EV is plenty of variance for quality HDR. Also works very well for blending vs HDR.

Used Photomatix on default tone mapping with light smoothing very high.



Full size here http://www.flickr.com/photos/davepalugyay/3244044361/sizes/o/

--
Tim
'I haven't been everywhere, but it's on my list.'
E3/E410/7-14/12-60/50-200/25/EC-14
http://www.flickr.com/photos/timskis6/