EOS-77D: is it possible to retrieve and keep…

[MarkSealey]

… the three component images taken by a Canon 77D when in an HDR mode, please?

I believe that the 70D cannot do this.

Thanks!

[MarkSealey]

Tim,

Thanks; Yes - I actually get my 77D today 🙂

Have no idea whether its HDR menu allows the separate export you kindly mention. If it does, I'm in business, I think, aren't I?

And you're right - that's exactly what I want to do. I want to get more control (Aurora in my case) over HDR.

Your rely appreciated!

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[MarkSealey]

Thanks, Tim; I don't know yet (get it today) whether the 77D allows export of all four images used by the camera's own HDR capabaility.

If it does, then that's exactly what I want to do - process the separate images in Aurora.

If it does not (allow four HDR image export individually), can I use bracketing in the same way as the camera uses HDR, please?

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[TCampbell]

I did some digging... turns out the 77D does not have in-camera HDR but it DOES have in-camera Auto-Exposure Bracketing.

In-camera auto-exposure bracketing was the feature that pre-dated HDR... you set the camera to take the normal exposure plus a bracketed shot both brighter and darker and you control the number of stops. 

You then process those into an HDR on your computer.  

[MarkSealey]

Thanks, Tim.

Would you say that getting those three bracketed exposures is as good as HDR inbuilt?

I'm still not sure whether I can get all three - e.g. with different filenames - off the SD card so that I can do that ('quasi'?)-HDR editing in something like Aurora.

Your help (and research) much appreciated 🙂

[TCampbell · Accepted solution]

All HDR is the result of post-processing... the question is whether you want to let the camera decide how to process it vs. you deciding how to process it on the computer.  I prefer having the control.

When you use built-in HDR or exposure bracketing (for cameras that have it) most cameras just grab 3 shots... the normal, plus 1 darker and 1 brigher exposure.  But for some scenes you may find you really want more than 3.  When I shot the total eclipse of the Sun this past August, I captured 12 exposure stops.

Every camera that has a manual exposure mode (which is every DSLR ever made) can capture the source data for HDR just as well as any other camera.  This is because the original method to collect the HDR data was to take a number of exposures and manual adjust the exposure between each shot.  Cameras with auto-bracketing do this for you... but often limit it to just 3 shots.  You may want more than 3 shots.

To determine how many shots you need, you would scan the scene with your eyes and try to find the darkest area you can find, and also find the brightest area you can find.  You would then meter both those areas and determine how many exposures difference there is between them.   The metering can be a bit tricky because most cameras don’t let you spot meter to a particularly tight area.  High-end hand-held light meters sometimes have a spot-meter tool that lets them pick off a 1° circle to meter.  But most meters are quite a bit wider than that ... and with a DSLR the size of that area depends on the focal length of the lens.  So the tightest area you meter could be quite wide and that means “bright” data is in that circle where you are just trying to meter “dark” data.

To get around that problem (without having to spend the money on a Sekonic L-858D series light meter) just take a test shot and check the histogram in the camera.  When you’re taking the “bright” exposure it is because you want to make sure you aren’t “clipping” the dark end of the histogram (the bright area will be clipped).  So you look at the in-camera histogram for the shot and make sure it doesn’t show any data up against the left side of the graph.  Similarly, test the dark exposure and make sure the histogram shows that no data is clipped in the highlights... there should be no data up against the right side of the graph.  If your histogram shows you got all the darks and all the brights (in two different shots) with no clipping... then your range of exposures will be adequate (even if you don’t have a $600 light meter).

It’s also generally not required that shoot every “stop” of exposure between your dark and bright end of the range... but you probably should grab every 2nd stop.    

Suppose I had an extreme range where I need the “normal” exposure plus 4 stops darker and also plus 4 stops brighter.  I can actually shoot the normal shot, then shoot a frame 2 stops darker, then another frame 4 stops darker (relative to the middle exposure), then 2 stops brigher and 4 stops brighter (so that’s a total of 5 images... -4, -2, 0, +2, +4... to get the range.)  It’s usually not necessary to get every 1 stop of exposure difference.  While most HDR software has no problem if you skip a stop and just every 2nd stop... it probably will struggle if you skip 2 stops and just grab every 3rd stop.  So I don't recommend pushing it too much.

Usually you don’t need that much range... often times grabbing 3 frames (-2, 0, +2) will be sufficient ... and for those shots, the in-camera Auto-Exposure Bracketing feature will do the trick.  Just be aware that it wont always do the trick and you may have to manually adjust the exposure between each frame when you need more range.

Just remember that the histogram is your go-to tool to confirm you really grabbed enough data.  If you're not completely comfortable with how to read the histogram, then you'd want to study up on that topic.

Lastly, a tip...

When I started shooting HDR and keeping the source data, it started to get confusing to figure out which frames go with which other frames.  I’d shoot a subject and grab my frames for HDR... then maybe change something and want to grab several more frames... and so on.  You get back to your computer and you import the data and now you’ve got a ton of frames that all look the same and you’re not quite sure WHICH sets were all taken as part of the same bracketed sequence.

A cheap trick (since we no longer have to pay for film) is to grab a dummy frame between each sequence... stick your hand in front of the lens and that can serve to separate the sequences.  It just makes it easier to sort through the data and grab the right frames that go together when you’re trying to run it through your HDR software.

[Waddizzle]

I do not always center my series of bracketed exposures around 0 Ev.

Just as you sometimes need to use exposure compensation on a single shot, I have frequently found a need to do something similar with a series of bracketed exposures.  For example, instead of using -1, 0, +1, i might use -2. -1, 0.

[MarkSealey]

Waddizzle,

Thanks so much. You not only endorse what Tim kindly says, of course, but increased my confidence in all of this by at least +1 or +2 🙂

Much appreciated!

[MarkSealey]

Tim!

Thanks so very much for taking the time and trouble to explain - completely and clearly - the direction in which I should be going and thinking. I really appreciate it; and I now know what I have to do!

I actually cut my photographic teeth 50 years ago using a Weston Mark V exposure meter and its 'Invercone'? with film. So I'm not afrain of lots of manual adjustments.

I suspect I shall also have to become more willing to improve my eye by much more trial and error than I have been used to.

I also like the idea of consciously departing from -1, 0, +1 and testing 2-stop variations; or even - presumably - vatiations like -1, 0 +2 etc. It's a challenge I shall happiy enjoy experimenting with.

I've clipped and save your entire reply and shall read it again and again until I can put what you say into practice. I somehow think that it won't take long to get where i want to go thanks to your clear description. Thanks again!

[benbraver]

Great answers by several other folks. Here's the simple solution I'm using (new to HDR):

I set the 77D for 3 bracketed exposures. Usually, just EV -1, 0 +1, and shooting mode RAW + JPG L. (The tip about taking a blank shot in between is great!) When I copy the images from the card to my computer, I use the JPG images to identify which three shots are the sequence I want to make the HDR from. I just write down or remember the .CR2 image file names.

So far, I'm getting great results with Aurora HDR 2018 for Windows from Skylum Software. (Also works with Mac.) In Aurora, I just do File Open, and select the 3 RAW images. Aurora will show thumbnails, and ask if these are the images you want made into one HDR image. Aurora then Loads and Merges the three images, and displays an HDR preview.

Of course, there are dozens of HDR style presets you can click on, and a ton of sliders you can play with (which I haven't yet). You can Save the HDR image in an Aurora file format so you can do further work on it later. You can also Export the HDR image to another format, like JPG. Yes, it's a few steps, but it's easy and so far it's worked great for me.