HDR Image Processing with Photomatix

March 13th, 2007


I’ve been having an interesting discussion with my friend Kevin Caskey about HDR (High Dynamic Range) processing of spherical panoramas. Kevin is a photographic savvy Realtor in Bellevue, WA that shoots his own spherical panoramas. Kevin discovered and pointed out Photomatix software to me. He showed me his QuickTime VR panorama of his living room that he processed created with Photomatrix.

The typical problem encountered when shooting panoramas is that since you have to shoot all shots being stitched together at the same exposure settings so that you can stitch them together so you have a hard time dealing with scenes that have an extreme dynamic range.

Here’s some background on HDR and Photomatix. The way HDR works is that in addition to the normal exposure you take one or more exposures with less exposure and one or more exposures with more exposure than the normally exposed image. You then combine the multiple images together in a way that takes the “best” parts of each image and results in an image that has a dynamic range of all the combined images. This combining process is what Photomatix does.

Why would you want to go to the work of taking multiple images and combining them? For interiors, it’s an alternative to artificial lighting. For outdoor shots it’s the only way to get the shot if you are faced with a wide range of brightness.

So Kevin used HDR processing with Photomatrix on this QuickTime VR shot of his living room. To appreciate this use of HDR, compare it with this panorama which is some of the same files from Kevin’s panorama only without HDR processing. This second shot is just one shot in each of 3 directions stitched together. Whereas Kevin’s shot is 3 shots in each of 3 directions and all 3 images in each direction combined with Photomatix and the final 3 HDR image stitched toghether. In comparing the two panoramas you will quickly see that Kevin’s HDR panorama has more even lighting around the whole 360 view much like you would get if you’d used a flash unit. In the non-HDR version of the panorama the lighting is more uneven around the 360 degrees of view. The windows are well exposed but the opposite direction is quite underexposed.

When working inside I’d rather use a external flash unit and take one shot in each direction since it’s a lot less processing work than using Photomatix and shooting 3 times more images. However, when you are shooting outside where you can’t can’t control the lighting there is no other way of capturing the total brightness range of a scene with a bright sky and not so bright foreground.

Last April I did a post on some ways to do image blending for interiors as an alternative to using lighting equipment. Photomatix is another piece of software that goes works in a similar way to the techniques I described in that post. However, with Photomatix you have much more control over the combining of images with a process that’s called “tone-mapping”. For a complete tutorial on HDR and using Photomatrix see www.naturescapes.net.

Share this

16 Responses to “HDR Image Processing with Photomatix”

  • I’ve never had much luck with any type of image using software to perform the HDR merge. I t always seems lacking. I end up just using the tried and true masking and hand painting, which on interiors, can be a PIA if there are finely detailed items in front of the window

    This is an image I did HDR just masking and painting. Took a while, though.

  • This product was actually referenced in your April post. However, the reference did not include mention on the pano stitching for virtual tours. I’m not a Virtual Tour provider, but I am curious about what kind of options there are for building your own tours, hostiing them and then posting to Realtor.com through their Picture Path program, without using a Big Box Virtual Tour provider or hosting program. The reason I ask is that the charge to host these tours is quite expensive.

  • Cherie,
    To host tours all you need is web space and the HTML know how. Tours can be just slideshows of still photos and those can be created with Photoshop Elements or Lightroom or other software. Creating 360VR images like the one above is a big subject and I’m in the process of writing an article on the subject because I get questions all the time on how to shot 360VR. Making a tour Picture Path compliant is some thing I’ll have to look into. To use a tour on most MLS sites and real estate websites tours don’t have to be Picture Path compliant. I think realtor.com created the specification just to create another revenue stream.

    I’ll do some checking and find out how to make a tour PP compliant. I’ve not payed any attention to Picture Path because I never post any of my tours on realtor.com.

  • Though I am never that thrilled with the results, I use Photomatix (no “r” in its name) every so often when shooting in to the sun and there has to be some sort of view out the window.

    As far as using it for 360 panoramas…I just ran a little experiment with Photomatix:
    It took me under a minute to pop off 24 shots of my living room with my pano set-up. The camera was set up to bracket 3 shots, each 2 stops apart (3 shots x 8 scenes = 24). Photomatix has a pretty easy batch processing feature. On my G4 laptop it took a little less than 10 minutes to make 8 HDRs. This was longer than I had expected (time for a new computer!!)

    So the HDR shots for 6 panos would take an hour to process. Kinda slow. However, it is all automated so one could be doing other tasks while the HDRs were being created.

  • Aaron,
    Thanks for correcting my spelling. I wasn’t paying attention.

    I have mixed feelings about how long it takes to grind through the processing with Photomatix. It would be different if the results were more spectacular but your’re right they usually aren’t.

  • Thanks for helping me look into it. I have the issue where all of the Realtors I work with, every single one, wants their photos posted to Realtor.com.

    I’ve been using a 3rd party program to build tours that are both MLS compliant and Branded. I don’t know that Panoramic Virtual Tours are going to be productive in my area…the midwest housing market is very different from coastal markets in that agents won’t pay a lot for professional photos. Many, as I’m sure you know, do not even believe that such services are necessary. It really is a matter of proving your worth. Should I make the investment to do panoramic virtual tours, the right way, I will have to find an option that produces high quality output. As an agent, I used Visual Tour for a time, but I wasn’t happy with the result and found it to be a waste of my budget dollars.

  • I downloaded the trial version of Photomatix yesterday, and played with a couple HDR ready exposures. In all, worked pretty good, even though it needed some more work in CS2 with curves to get the contrast back. Much quicker, though, than doing it by hand! And, from what I’ve been able to detirmine, much better results than the built in CS2 HDR merge feature.

    The one thing that you really need to watch on these auto HDR programs is the ‘gray out’ of the image. I notice it even on the above example image. These programs don’t know the only thing you want merged is the windows, and they tend to blend some of the 2 interior exposures together.

    But, since I’m not entering these in a photo contest, I’d say it’s well worth the hour I save hand merging it!

  • I am a Realtor/VTour Producer in CT. I prefer the natural light pano. The HDR stuff is a bit artistic for my taste. Try this for HDR and see some amazing stuff. I tend to blow out the window to the point of bleeding if necessary to get the shadows with all interior lights turned on and any non auto WB setting, shoot in raw and balance what you can.

    Enough of that though you are right shooting pano directions are enough for a book. To the Realtor.com point Picture Path is not so much a format as subscription. Picture Path providers have a protected (somewhat) geography and pay an initial $5k fee (depending on the active number of listings in that area code) and then an annual rate. They host the media, the PP Provider, on their own servers. I use an organization called
    and they charge 9$ to host a tour and $20 to put it on Realtor.com, unless the Realtor subscribes to the Featured homes package whereby there is no additional charge. Now I say it takes a good 3 hours to produce these things. From first phone call to up on Realtor.com I get $150 but you can get it done for less with circle pix who charges $79, but they look like . I think mine have a better quality and of course offer the 360 vertical and 360 horizontal

    a second picture path provider is http://www.hometour360virtualtours.com/

  • Thanks for the info about Picture Path. I’m not the kind of person that would usually climb atop a soap box, but I find it unbelievable that Realtor.com charges so much. When I was working as an agent, I got slammed with the annual NAR fees, as well as state and local Realtor board fees. Then, in order to just display additional photo content on Realtor.com (owned/operated by NAR), I was paying over $1500 annually…that was with my office’s huge discount. Now that I’ve left my real estate career behind to pursue something with less overhead, I find that Realtor.com is still reaming me. I should have known that it wasn’t going to be as simple as just signing a complaince document, as they describe on their website. I know I said this already, but UNBELIEVABLE! They are making millions off Picture Path providers alone, so I really don’t understand why they must charge their true supporters, the REALTORS, so much! Clearly, they are in it to make money, not to help Realtors sell their properties.

    Isn’t it strange how many real estate agents cross over into the realm of photography & virtual tours. It appears that everything related to real estate is quite expensive.

  • If you would like more info on HDR…Jack Howard from Popular Photography Magazine (Popphoto.com) has a new e-book available titled
    “HDR: An Introduction to High Dynamic Range Photography”.

    http://www.oreilly.com/catalog/9780596510176/

  • I too didn’t think the results looked natural for this type of HDR when blending a window exposure with the interior.
    However, the other day a came across the HRD for Dummies free PS plug-in http://www.360vr.com/hdrfordummies/ which seems to work a treat if all you want to do is this type of hdr. It’s very quick and simple, you just open the dark image, drag the lightest image on top as a new layer and press the action. You can always drag the lighter copy on top of the (flattend layers) hdr image again and quicky mask out the main areas of the shot if it is still a little too dark

  • Mvus,
    Thanks for pointing out Jook Leung’s action. I think I’ve even downloaded this back when Jook first posted this but I completely forgot about it. I’ll check it out.

  • I have been shooting real estate for the last couple years and use Photomatix on just about every shoot. I only own a couple speedlights and wireless triggers which are nice for accent lighting but not powerful enough to light a full living room. I don’t do any panos for real estate but have found that I get the best results if I shoot at least 5 images per bracket (-2, -1, 0, +1, +2). I only shoot raws and process with rawshooter. I’ll usually make the hdr image and then process one of the raw files how I normally do and blend the hdr into the normal single exposure shot. This will usually eliminate the wierd color casts and wacky contrast that photomatix is known for. You can see some examples of my work here:

    http://www.pierpontblvd.com

  • Came across this HDR Referrence today. The interesting part is not about th HD Photo format but the comment on in-camera HDR production. These would be awesome for Real Estate.

    http://www.tgdaily.com/index.php?option=com_content&task=view&id=31492

  • HDR has three major flaws for serious real estate photography:
    Time Consuming
    No Batch processsing or consistent results
    Too much noise

    Otherwise, one great technic that only needs to mature… if Nikon and Canon don’t make it available “on-camera” like the D300 Active D-lighting !

    It still early to pretend replacing post processing hdr, but it might get there fast.

    L

Trackback URI Comments RSS

Leave a Reply