EOS Rebel T8i previewing exposures longer than 30 seconds

[stevet1]

Let's say I want to take a long exposure in bulb mode. This exposure will take 1 minute, or 2 minutes, or 4 minutes - something that will go beyond the 30 second limit in manual mode.

Will I see what my anticipated exposure looks like on the LCD screen in Exposure Simulation before taking my shot?

Or do I just have to take the shot and review the results afterward?

If this is not the proper forum for this type of question, just let me know.

Steve Thomas

[Tiffany]

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Thank you.

[kvbarkley]

We don't need to know the camera. There is no way to simulate bulb mode since the camera has no way of knowing how long the shutter will be open. Which is the point of bulb mode.

[stevet1]

Tiffany,

Thanks.

I've been thinking about this, and I think I've found the answer to my question.

The answer is no, because, on the camera at least, there is no way to set a timer in Bulb mode, so the camera would have no way of knowing what a 2 minute exposure would look like.

I've been using an app called Camera Connect and Control installed on my tablet to address long exposure issues, and it does have a timer for Bulb Mode. You set the timer for 13 seconds, or whatever, and, after it counts down, at the end of your timer, the shutter closes automatically.

I have a T8i, and to the best of my knowledge, which is very limited, no camera has this feature in Bulb Mode.

Using the app I mentioned, I can see the affect various shutter speeds will have before I take my shot, but to date, I haven't looked at extended long exposures running into minutes. 

I think I will look into that tomorrow.

Steve Thomas

[stevet1]

kvbarkley,

I hope you got a chance to see my answer to Tiffany.

You see these guys who display a wonderful photo and they say, "This was a 4 minute exposure.", and I've wondered, "How could they know what a 4 minute exposure was going to look like?"

Sure, they could use an Exposure app, or do the math in their head, and know what exposure they should set, but I wondered if there was a way of telling ahead of time, how it was going turn out.

Is it just a matter of numerous trials and errors? Should the exposure have been 3 minutes and 30 seconds? Should it have been 3 minutes and 45 seconds? Should it have been 4 minutes and 10 seconds?

It would be a drag to take a 4 minute exposure, and then wait another 4 minutes for the Long Exposure Noise Reduction to do its thing, only to find out you've underexposed, or overexposed your shot. 

And if you have, how do you know how much to tweak it?

I just wondered if there was a way to look at things ahead of time.

Steve Thomas

[kvbarkley]

You use an exposure app or a table. The nice thing is that at long exposures you don't have to be that accurate. Between 4 and 8 minutes is one stop, so between 3 and 5 will yield pretty much the same exposure.

[stevet1]

kvbarkley,

You wrote, "You use an exposure app or a table. The nice thing is that at long exposures you don't have to be that accurate. Between 4 and 8 minutes is one stop, so between 3 and 5 will yield pretty much the same exposure."

Hmmm...    Hadn't thought of that. Lot's of flexibility in there.

I tested it out this morning. The Exposure Simulation didn't appear to be working in Bulb Mode using remote shooting either. Once you hit that 30" ceiling, you're on your own 😀

The Bulb Timer function is still pretty neat though. The app handles closing the shutter for you. 

Steve Thomas

[ebiggs1]

"Is it just a matter of numerous trials and errors?"

Yes, but it is also from experience. Keep in mind at one time we didn't have any 'auto' anything. Amazingly we still got the shots. When you select bulb in your Rebel this is the same thing as full manual. Guess what after a few trials and screw-ups you will learn. Plus you don't have to burn expensive film to do so like we did.

[jrhoffman75]

For astro photography folks will frequently shoot at a very high ISO to get SS within camera range for exposure determination. Also helps to frame the image when its dark. Then use the equivalencies to compute time at the desired ISO.

[kvbarkley]

For digital we don't have to worry about reciprocity failure!