Questions on Bracketing Exposures

[Brownbear]

This morning I went on a hike to photograph a scene at a lake. I forgot my Graduated ND filters and I had to bracket the exposures to account for the brightness of the sky and dark forest. (I have very little experience bracketing)

My camera is a Nikon D7100. I'm using back button focus (a recent switch, and this morning is the first time I've tried bracketing with BBF)

I set my bracketing for 3 frames +1 and also +2 exposure, and pressed the ok button to ensure auto bracketing was set.

I switched between Single Shot auto focus, and Continuous auto focus

Whilst 'auto bracketing' remains set (until I cancel it) the camera will cycle through the same three exposure settings so, if my 'drive' is set to single shot, I must remember to take three shots of each scene. However, if I set the 'drive' to 'continuous shooting' mode, it will take three shots (at the different exposures) and stop. This seems a much better way to work, especially on the high speed drive setting, I can take three exposures in rapid succession, so the shots will be almost identical and I don't have to remember how many shots I have taken.

Quote from this link...

http://www.geofflawrence.com/bracketing_exposures.html

I started out using Aperture priority, with a set iso at 100 than auto iso set to 320 (wind on the trees)... It seems that even though I had the bracketing function turned on, my camera wasn't giving me 3 shots at different exposures.. So I switched to manual mode with a set and also with auto iso (trying everything to figure it out) with auto bracketing I did receive 3 shots at different exposures each time... That auto bracketing worked in manual mode and not in aperture priority seemed incorrect? If anything I would expect it to be the other way around.

My apologies for the confusing post but I'm confused.

Thank you.

[PhotomanJohn]

Christina - The note on page 136 of the camera manual does a pretty good job of explaining the operation in the various modes and yes bracketing does work in manual exposure mode by varying the shutter speed as it does in aperture exposure mode. Auto ISO is used differently depending on the mode which is described in that note.

You did not mention if you had the drive setting to continuous where the camera will take all of the exposures with one push of the shutter button. Using back button focus does not affect the bracketing operation.

John

[Mike Buckley]

From page 136 of your manual:

"The camera modifies exposure by varying shutter speed and aperture (mode P), aperture
(mode S), or shutter speed (modes A and M). If On is selected for ISO sensitivity settings > Auto ISO sensitivity control (page 81) in modes P, S, and A, the camera will automatically vary ISO sensitivity for optimum exposure when the limits of the camera exposure system are exceeded; in mode M, the camera will first use auto ISO sensitivity control to bring exposure as close as possible to the optimum and then bracket this exposure by varying shutter speed."

It seems that even though I had the bracketing function turned on, my camera wasn't always putting out 3 shots at different exposures.

I would be willing to bet that it did. Check the EXIF data to verify that. You can view it using the camera if your memory card is in the camera or you can view it using your computer and software once the images are downloaded to your computer.

[Polar01]

Christina why the auto ISO? If using Aperture priority, set aperture, set ISO (no auto), set number of shots, and then the exposure difference. Set to high speed, focus, then push shutter and hold until all the shots taken. Do not set anything that will allow the camera to change anything other than shutter speed which you have done by telling it (camera) the compensation will want it to do +/- number.

Cheers: Allan

[Mike Buckley]

Christina why the auto ISO?

The only reason to use that setting would be to force the camera to change the ISO rather than the shutter speed. Having said that, I don't know why changing the ISO rather than the shutter speed would be an advantage when capturing a landscape scene.

[Brownbear]

Thank you John, Mike and Allan... As always appreciated.

My apologies for not checking my manual (I will read up on it)... I assumed that the info wouldn't be great and instead did an internet search on the subject and reading the various results, added to my confusion.


John...

I started out with single shot shot mode, and switched to continuous mode, and back and forth, likely because when I wasn't seeing 3 exposures I wanted to see if something was effecting the other functions... The last time I tried bracketing was before I was using BBF so I was of the mind that BBF might change something. (thank you)

And also because I read this which I think is why I wasn't getting 3 exposures?

if my 'drive' is set to single shot, I must remember to take three shots of each scene. However, if I set the 'drive' to 'continuous shooting' mode, it will take three shots (at the different exposures) and stop.

Mike...

After I took the image(s) I checked my camera to see if there were 3 exposures and there was only one image for sure, and that is why I started trying every possibility I could think of to get three exposures.

Allan and Mike...

I started out using my tripod but decided to lay down on ground (no tripod) and I wanted a faster shutter speed for hand holding and also to account for the wind blowing on the tree tops. First with aperture priority, and then in Manual with the ISO fixed at 320 and possibly auto iso, too... When I couldn't get 3 exposures each time, confusion set in. I was frustrated because I couldn't figure out why, so I started switching back and forth between single shot and continuous focus mode, and aperture priority and manual. Honestly, I can't remember the why of everything I tried.

I need to learn more about bracketing. I will practice it on something simple close to home before trying it again. I prefer to use my graduated filters and I've avoided using this feature of my camera.

Thank you to all.

[Stagecoach]

I don't know why changing the ISO rather than the shutter speed would be an advantage when capturing a landscape scene.

Mike, would this not be an advantage if you wanted to dictate a 'minimum' speed to arrest any foliage movement caused by wind?

[Stagecoach]

Hi Christina,

And also because I read this which I think is why I wasn't getting 3 exposures?

if my 'drive' is set to single shot, I must remember to take three shots of each scene. However, if I set the 'drive' to 'continuous shooting' mode, it will take three shots (at the different exposures) and stop.
.

I have not bracketed for a while but when last undertaking it for early morning (little light) shots on the D300 I set a bracket range of 5 exposures (3 or 7 the same) and also the 'maximum' No of shots that could be taken in a single burst to 5.

With my cable remote (or would be the same if using the shutter button) I simply kept it pressed and off shot the 5. I found this basically foolproof, no counting or worrying.

Grahame

[Mike Buckley]

Mike, would this not be an advantage if you wanted to dictate a 'minimum' speed to arrest any foliage movement caused by wind?

Yes, that could be a valid reason but there are other ways to accomplish the same thing. As an example, I would rather configure the camera to either Aperture priority or to Manual mode with Auto ISO disabled and using settings that would render the slowest shutter speed in the bracket to be fast enough. That's because, for me, ensuring the lowest possible ISO and using the same ISO would be a lot more important to me when using a bracketed set.

[Brownbear]

Hi Grahame,

Thank you. Yes, I was out at sunrise and I did set my exposures at 3 (and I also tried 5). I started out in aperture priority mode and single shot (because I like to hear the beep upon focus), and truly there were times when I received only one exposure instead of 3 or 5.

I almost always use continuous autofocus mode, and use single shot mode only for landscapes and the like.

Are you saying that in single shot mode that you receive 3 or 5 exposures with just one click of the shutter/remote?

Anyhow, I will try it out again using single and continuous the very first chance that I receive.

Sorry for the confusing thread. I should've simply asked why I wasn't receiving 3 exposures even though I set my camera to this.

Hi Christina,



I have not bracketed for a while but when last undertaking it for early morning (little light) shots on the D300 I set a bracket range of 5 exposures (3 or 7 the same) and also the 'maximum' No of shots that could be taken in a single burst to 5.

With my cable remote (or would be the same if using the shutter button) I simply kept it pressed and off shot the 5. I found this basically foolproof, no counting or worrying.

Grahame

[Mike Buckley]

Christina,

When trying to figure out how your camera works, I recommend that you always go to the manual first. The manual is terrible at explaining how to use your camera to achieve a particular look but it's pretty good at explaining how to configure your camera to make it to work a particular way.

You first explained that your camera wasn't putting out three shots at different exposures, which led me to think you were saying that it was producing three shots but not all at different exposures. You're now saying that the camera definitely didn't produce three exposures. That being the case, there are only three possibilities I can think of and I'm sorry to say that all of them are due to my most frequent kind of error -- operator error: You either used single shot mode but didn't release the shutter three times, you used Continuous mode but didn't hold your finger down long enough, or you didn't have your camera configured to use the Auto Bracketing. It's probably the latter issue, as I seem to remember that you have to press the OK button to set the change you made and it's very easy to forget to do that, especially when you're not used to using Auto Bracketing.

Perhaps the most important suggestion we could make is that you always leave your essential photo gear such as your ND filters inside or attached to your bag so you never have to worry about accidentally forgetting them.

[William W]

This morning I went on a hike to photograph a scene at a lake. I forgot my ND filters and I had to bracket the exposures to account for the brightness of the sky and dark forest.

Could you please clarify, was the purpose of bracketing to later merge the three images for High Dynamic Range Imaging Technique?

Ta.

WW

[Brownbear]

Christina,

You first explained that your camera wasn't putting out three shots at different exposures, which led me to think you were saying that it was producing three shots but not all at different exposures. You're now saying that the camera definitely didn't produce three exposures.

True... My apologies for the confusion.

You either used single shot mode but didn't release the shutter three times...

It is definitely the case that...
I used single shot mode but didn't release the shutter 3 times. For some reason, I thought that my camera would do this automatically, and this is what led to everything else. (I did press the ok button)

I just tried single shot mode, with the bracketing function set. I pressed the shutter 3 times and it worked perfectly.

Perhaps the most important suggestion we could make is that you always leave your essential photo gear such as your ND filters inside or attached to your bag so you never have to worry about accidentally forgetting them.

Indeed! Will do. Much easier than bracketing and combining exposures.

Thank you to everyone. Perhaps there is someone else out there who is just as dim-witted as I can be at times. Granted it was very early in the morning.

[Brownbear]

Hi Bill,

Yes. At sunrise in the forest by a lake and a mountain, and impossible to expose for the forest and the sky because of the high dynamic range of the scene.

Could you please clarify, was the purpose of bracketing to later merge the three images for High Dynamic Range Imaging Technique?

Ta.

WW

[pnodrog]

I assume they were graduated ND filters you forgot. ND filters just increase the overall exposure required for a single exposure and are not compensated for by bracketing. Blending multiple shots consistently exposed can be a substitute for ND filters for some effects.

Grad ND can assist in capturing a high dynamic range scene

[Brownbear]

Hi L. Paul,

Yes, I was referring to my graduated ND filters. I don't have any ND filters, yet.

I will edit my original post to reflect this. Thank you.

I assume they were graduated ND filters you forgot. ND filters just increase the overall exposure required for a single exposure and are not compensated for by bracketing. Blending multiple shots consistently exposed can be a substitute for ND filters for some effects.

Grad ND can assist in capturing a high dynamic range scene

[Mike Buckley]

Well, now, Christina, if you were being dim-witted so was I about the very same issue when I first came upon it. I distinctly remember thinking that releasing the shutter once would cause the camera to take all three captures. There was a similar mode on my Nikon point-and-shoot camera I had been using that required releasing the shutter only once so I assumed using this mode on my DSLR would work the same way. It doesn't and I think that's a failing of Nikon engineers more than a failing of you and me. I concede that I have a biased perspective when making that determination.

[dje]

Perhaps there is someone else out there who is just as dim-witted as I can be at times.

If it's any consolation Christina, I'll "fess up" to that too (when I changed from Canon to Nikon). Canon was different I believe with only one press required irrespective of the shooting mode selected.

Dave

[Mike Buckley]

only one press required irrespective of the shooting mode selected.

I can't think of a situation in which I would plan to release the shutter the first time, wait and release a second time, and wait yet again and release a third time. So, I also can't imagine why Nikon made it possible to do that.

[Brownbear]

Thank you for sharing. I feel much better knowing that.

Well, now, Christina, if you were being dim-witted so was I about the very same issue when I first came upon it. I distinctly remember thinking that releasing the shutter once would cause the camera to take all three captures. There was a similar mode on my Nikon point-and-shoot camera I had been using that required releasing the shutter only once so I assumed using this mode on my DSLR would work the same way. It doesn't and I think that's a failing of Nikon engineers more than a failing of you and me. I concede that I have a biased perspective when making that determination.