If you have seen my flickr photostream, you should know that I go to a lot of car shows, and shoot almost all my shots in HDR. I am fortunate enough to live about 5 minutes from a weekly car show called Cars and Coffee here on the border of Las Vegas and Henderson. Just this past weekend, it was perfect weather with overcast skies but no sun – giving us a nice even light with no annoying bright sun ruining many angles. So here is one of my favorite shots from that day.

The Shoot
I carried my tripod that day, ensuring many stable auto-bracketed HDR sets. The lighting worked for almost any angle works because there is no sun to worry about. I set the tripod up behind this Mini Cooper S and fired off 3 shots with the Canon 5D and 17-40mm f/4 lens (essential for car shows and landscapes). Cars usually look good from the corner angles and given a bit of tilt to add perceived motion and aggressiveness. A shot from the ground (mouse-eye view) usually works good too, but this time I opted for eye-level looking down so you can see the top of the Mini. The deep metallic grey and double yellow lines really makes this particular Mini stand out, and I thought it would turn out well in HDR. You decide:

By pongky ©

The Processing
Since the AEB set of exposures were shot on a tripod, I didn’t have to check the “align images” box in Photomatix – thus reducing the merging time. I dragged it into Photomatix and made sure I adjusted the colors and exposure levels. Usually what I do in Photomatix is increase the gamma so that it looks slightly overexposed (maybe by half a stop) so that I can do more with it in Lightroom in terms of blacks and contrasts. I find this technique works very well. In Lightroom I cropped out all the useless background elements (which is why the roof is partially cut) and adjusted the tones and color saturation to get it to this point. I hope you like it – and if you are really interested, you can also have the AEB RAW files by downloading from here. Let me know if you use it and come up with another result!

The Shoot
It was a blistering hot summer day in 2008, and I still had my Nikon D200 which can do a decent frame rate so I was able to get a 7-exposure AEB going with this cheerful-looking children’s play area in Las Vegas. I remember the temperatures were still around 100-110 degrees fahrenheit that day, hence the missing children and park-goers. I only took one set of auto-bracketed exposures so I had to make it count – so I propped the camera on something – I think it was a metal piece on another jungle-jim set. I squeezed off 7 exposures using the “cH” setting to make sure I minimized hand shake. The AEB was in the range of -4, -2 2/3, -1 1/3, 0, +1 1/3, +2 2/3, +4 EV.

The Processing
The vibrance of the red, yellow and blue playground set definitely needed to be preserved. Halos needed to be controlled in the sky in Photomatix. Surprisingly Photomatix was able to align it almost perfectly. I wanted to desaturate the sky a little so that the blue in the playground set would be more prominent, but I think overall it turned out well. The details were preserved in the dark areas under the canopy such as the underside and interior of those slide tubes. The only halo that is noticable is on the right side of the image in the sky – which I’ll live with, considering the rest of the image “works”.

Have you ever wondered how much that extra exposure value (EV) range would help improve your next HDR image? Would, an image taken at 3 exposures at -2,0,and+2 EV be better than an image taken at -4,0 and +4 EV? This article will help you determine this issue. Does using more exposures really improve image quality?

Depending on the camera you use, you might run into some technical limitations. Some cameras (such as the Canon EOS 5D) is only able to take an auto-exposure bracketing (AEB) set of 3 exposures with the maximum range of 4 EV. If you want to do 5 or 7 exposures you need a tripod and have to do some creative exposure adjustments to get the extended range. Nikon’s D200 and above offers up to 7 auto-bracketed exposures going up to +4 and -4 EV I believe, totaling a range of 8 EV in total! I know someone on flickr who does a whopping 17 exposure HDR!

Well, when we get down to it, it’s really the image quality result is what we aim for. I have an auto bracketed set of a scene here in Las Vegas of the west valley wall. I believe I captured 5 auto bracketed exposures, at -4, -2, 0, +2 and +4 EV. We will try to mix the exposures up so you can see what works well and what does not. Note that these are images exported as tiff via Photomatix using the same exact Details Enhancer settings, and has not been further processed in another software.

A) EV -4,-2,0,+2,+4 (all 5 exposures merged)

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B) EV -2,0,+2 (3 exposures)

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C) EV -4,0,+4 (3 exposures)

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D) EV -4 +4 (2 exposures)

(Click to enlarge)

So you can see very little difference between A and B. C seems to be a little faded and washed out due to the higher range differential than A and B. D is obviously very noisy and not a satisfactory result. If you compare B and C,I think the smaller EV range results in a better image quality. The local contrast using 5 exposures seem to be higher (A), but otherwise the tones and color definitions are extremely similar. After further edits in Lightroom I figure you could not tell the difference between the A and B.

So, in conclusion, I would say that it is not worth the extra effort if you did a 5-exposure HDR versus a 3-exposure HDR – where you save time is in the HDR merging and also file storage savings. I am now happy with the -2, 0, +2 EV maximum range on my Canon EOS 5D.

If anyone has any input about 7 or 9 exposures and higher, please let me know.

To HDR, or not to HDR? The question may arise for your next car photo. Is it worth the extra 5-10 minutes in merging, aligning the multiple exposures to create the HDR look, or is it just as good or better if you just edit the single RAW as is? Some would say they like the look of non-HDR images better. So here’s a side-by-side look at how an image that is processed as a single RAW (top) compared to an HDR processed image (bottom). Both are processed similarly in Lightroom. Can you spot the differences (click to view large)

The new 2010 Audi TT.

Let us ignore the color saturation, as that can be corrected in Lightroom. Instead we can focus on the darker areas of the top image — especially towards the lower left of the image where the left edge of the bumper is. See how much brighter and clearer the HDR version is? The contrast between the bright reflections and the dark on the glossy car surface is more apparent in the HDR version – as you can see the rear A pillar seems much more dark than the non-HDR version. There just seems to be an extra coat of super glossy clearcoat on the car in the HDR version.

Another very apparent difference is in how much detail can be seen on the surface of the roadway in the HDR version as it’s able to bring out more details in the shadows.

However, there are some “bad” HDR artifcats that can be found in the lower image, such as the movement of the people apparent in the right part of the rear bumper (ghosting) and also in the person sitting on the chair who turned his head during the 3-exposure bracketing (I say he’s been HDR-ized). It’s up to you which look fits what you need or like better – but since you are reading this site, it seems like you’ve already gone to the dark side of photography — the HDR side, that is.