Why so many shots?

amolitor · Jul 13, 2012

Why do HDR practitioners use some many exposures? I always see stuff like '7 exposures, one stop apart' for some scene that looks like maybe it was 12 stops wide.

Why don't people space the shots out further? Virtually any camera will give you 8 stops of range, and I guess it doesn't hurt to have a few stops of overlap, but why not space thing 6 or 7 stops apart? Spacing stuff by 1 stop just seems to produce a massive pile of redundant image data, and accompanying problems stitching these huge heap of images together.

I swear I recently saw some pretty ordinary looking scene that claims 22 exposures or something. Madness.

Am I missing some technical detail?

480sparky · Jul 13, 2012

Frames are cheap and easy to create............. while in the field.

I'd rather take 20 shots and only use 4 of 'em than to sit in front of my monitor with 4 frames cursing myself for not taking 20.

"It's better to have them and not need them than need them and not have them." You can quote me on that.

ceejtank · Jul 13, 2012

480sparky said:
"It's better to have them and not need them than need them and not have them."

Consider that done. QUOTED.

amolitor · Jul 13, 2012

Having 'em, sure. What I can't figure out is why you'd pile them all into a single image.

Overread · Jul 13, 2012

I suspect it depends how they approach the HDR - I would guess that if they are letting software make most of the choices, then the software has a higher chance of giving a good result with access to more data (ie more frames). It might also make tweaking of settings within the software (for different effects) a lot easier - again because its more data to work from.

If its a simpler scene and you can manually blend the results then fewer frames might indeed be all that you need.

In the end the difference in approach might well not give much of an actual difference in result (depending how people work); but having access to the additional frames essentially costs the person nothing in the digital age and thus having more options can help in select situations.

o hey tyler · Jul 13, 2012

amolitor said:
Having 'em, sure. What I can't figure out is why you'd pile them all into a single image.

Probably for the lulz?

rexbobcat · Jul 13, 2012

They don't always do that. The more exposures you have the more noise you will have even though it's not always obvious.

EDL · Jul 13, 2012

Most HDR's I see are three exposures and sometime I see 5 or 7. Not sure where you get the idea that all HDR examples are "so many frames". The basics are pretty simple, you only need enough frames to cover the full dynamic range of the scene. As mentioned, with digital it's a heck of a lot easier to take too many frames and disguard what you don't need (or want) than it is to not have them and need them.

Not sure that it's madness either.

jake337 · Jul 13, 2012

Maybe they were shooting directly into the sun with dark shade in the scene as well?

amolitor · Jul 13, 2012

I didn't say they "all", just that many seem to use a lot of exposures. Search for "17 shot HDR" on flickr, for instance. Or any other number you care to name. You don't get a LOT of hits, but you get some, and that's surely not the only phrase people use. Some of the more outrageous examples seem to be panos in addition to being HDR, but I'm just not feeling more than 3 or 4 exposures as needed for pretty much anything. 4 exposures, 8 stops apart, for instance would give you enough range to image the surface of the sun together with a dimly lit room.

Someone, somewhere, gave these people the idea that a Whole Bunch Of Exposures was a good idea.

Since nobody's mentioning a technical reason for it, I am going to assume that there's not one.

EDL · Jul 13, 2012

Well, find something to shoot and do 20 frames then process a three frame and process all the frames and see if it makes a difference. I'm not saying that flippantly because I honestly don't know the answer. I may try it myself just to see if it does make a difference when processed. I can imagine that the software you use to process it with will make a difference too.

1hdr4u · Jul 14, 2012

I only use 3 shots because that's all my camera(canon 60d) will allow me in bracket mode. I shoot a lot if not most of my HDR handheld and then let my camera fire off my shots. I've been happy with the results from only 3 shots.

jake337 · Jul 14, 2012

1hdr4u said:
I only use 3 shots because that's all my camera(canon 60d) will allow me in bracket mode. I shoot a lot if not most of my HDR handheld and then let my camera fire off my shots. I've been happy with the results from only 3 shots.

You can manually bracket as many exposures as you desire.

jake337 · Jul 14, 2012

amolitor said:
I didn't say they "all", just that many seem to use a lot of exposures. Search for "17 shot HDR" on flickr, for instance. Or any other number you care to name. You don't get a LOT of hits, but you get some, and that's surely not the only phrase people use. Some of the more outrageous examples seem to be panos in addition to being HDR, but I'm just not feeling more than 3 or 4 exposures as needed for pretty much anything. 4 exposures, 8 stops apart, for instance would give you enough range to image the surface of the sun together with a dimly lit room.

Someone, somewhere, gave these people the idea that a Whole Bunch Of Exposures was a good idea.

Since nobody's mentioning a technical reason for it, I am going to assume that there's not one.

I'm not really sure either but here is a guess.

Lets say a scene has a very dynamic range. Next lets say the photographer in question is looking for specific exposures for certain areas of the scene. The photographer may meter for each specific area so, that when brought into post and combined, these specific areas of the scene are exposed to exactly where the photographer wants. This way there is less tweaking to get the desired effect they want in those areas.

Not sure but just a thought.