I am considering purchase of a D7100. From the manual, I cannot tell if it can do one thing I want: shoot a continuous series of long (say, 5 second) exposures - one after the other with no (or very small) time gap in-between. One could thing of this as a time-lapse with the interval between shots of zero.
Can D7100 shoot continuous series of long exposures?
- Thread starter meso
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Horoscope Fish
Senior Member
Well the answer is both yes, and no...
I haven't done any long exposure shots in a while but I do have a D7100 and the last long exposure shooting I did used that body... I'm going by memory here but it sticks in my mind when you do long exposure shots, say a five-second exposure, the camera requires time to process the shot once the shutter closes and, typically, the time it takes to do that processing equals the exposure time. That means your five-second exposure is going to need roughly five seconds to process in-camera. If you're shooting JPG and enable Long Exposure Noise Reduction you need to double the processing time so now your five-second exposure is going to require (roughly) ten seconds to process.
So, yes; you can set a D7100 to shoot consecutive long-exposure shots, but you need to factor in processing time between those shots...
So, no; you can't have a "zero interval" between captures.
Now I fully admit I am going by memory on this so if someone knows with certainty that I'm off base here... Please correct me.
.....
Don Kuykendall_RIP
RIP :(
I think with any camera you are going to have some lag because the camera has to have time to process the photo and write it to the card. There are many variables like what format you are shooting. RAW is going to take longer than JPEG. JPEG Fine Large is going to take longer than JPEG small. There are trade offs at every turn. These are not camera specific. There are other settings that affect that time also like in-camera noise reduction.
Again lots of variables But with everything set correctly the time lag can be fairly short.
Now for the main question...What are you shooting where you would want a long exposure with no lag in-between? i have done some very long time lapse series with 6,000 to 7,000 shots and for most you need some time between shots or the resulting movie is going to be very short. Most time-lapse movie editing involves running the sequences at 30 frames per second. That is how I figure out what my shooting rate should be.
How long is the event I want to shoot? Say one hour
3600 (total time) X 30 (frames per second) = 108,000 total frames to give you a time lapse one hour long
108,000 per hour gives you 1800 per minute divided by 4 (for 15 seconds) give you 450 frames you need to shoot to get a 15 second time lapse of a one hour long event
This should tell you you need to shoot 1 frame every 8 seconds.
Does this totally confuse you? I took me a while to figure all this out the first time
Here is one i did about a year or so ago. this was my daughters car getting wrapped. The event took about 8 hours and was 6,000 to 7,000 frames
https://www.youtube.com/watch?v=kdp48vXxYts
Again lots of variables But with everything set correctly the time lag can be fairly short.
Now for the main question...What are you shooting where you would want a long exposure with no lag in-between? i have done some very long time lapse series with 6,000 to 7,000 shots and for most you need some time between shots or the resulting movie is going to be very short. Most time-lapse movie editing involves running the sequences at 30 frames per second. That is how I figure out what my shooting rate should be.
How long is the event I want to shoot? Say one hour
3600 (total time) X 30 (frames per second) = 108,000 total frames to give you a time lapse one hour long
108,000 per hour gives you 1800 per minute divided by 4 (for 15 seconds) give you 450 frames you need to shoot to get a 15 second time lapse of a one hour long event
This should tell you you need to shoot 1 frame every 8 seconds.
Does this totally confuse you? I took me a while to figure all this out the first time
Here is one i did about a year or so ago. this was my daughters car getting wrapped. The event took about 8 hours and was 6,000 to 7,000 frames
https://www.youtube.com/watch?v=kdp48vXxYts
This is only if you have long exposure noise reduction turned on. If the NR is turned off, it only takes as long as any other photo to process. This is based on my shooting in RAW+JPG anyway...
How many shots do you foresee yourself shooting continuously?
From my experience shooting star trails with a D7000 and D600 (principles should be similar to D7100). I've had to add a small amount of time (2 or 3 seconds) in between shots of about 500 or so. If I didn't put a pause then the series would only get to about 20 or 40 photos before stopping (rather than the full 500). I think this is due to it trying to write data to the card.
So I agree with Horoscope that some time is needed but I'm not sure if it's the full amount of time as the actual exposure. I know my exposures were about 30 seconds and my pause time between shots was a couple of seconds.
From my experience shooting star trails with a D7000 and D600 (principles should be similar to D7100). I've had to add a small amount of time (2 or 3 seconds) in between shots of about 500 or so. If I didn't put a pause then the series would only get to about 20 or 40 photos before stopping (rather than the full 500). I think this is due to it trying to write data to the card.
So I agree with Horoscope that some time is needed but I'm not sure if it's the full amount of time as the actual exposure. I know my exposures were about 30 seconds and my pause time between shots was a couple of seconds.
How silly of me... WELCOME TO THE FORUMS meso!
BackdoorArts
Senior Member
Maybe, but not as easily as any human would like. Why? Read on.
The intervalometer on the camera allows up to 999 occurrences of 1-9 consecutive images taken at intervals of X seconds where X is at least 1. So, you could conceivably shoot 9 frames one after the other and then have to wait 1 second before it fires again, but that wouldn't be even, so let's assume that you're simply going to shoot 1 image per occurrence which means you can have at most 999 images before manual intervention.
Here's where it gets interesting - the interval doesn't start when the shutter closes, it starts when the shutter opens, so if you have a 5 second exposure then you need a 6 second interval between shots. Why? Because if you set it at anything less then those intervals will try and fire while your shutter is open, effectively reducing the number of shots you actually take. So, if you had the interval at 1 second and the shutter speed at 5 seconds, then interval 1 fires the camera, intervals 2-5 and maybe 6 try and fire while the shutter is open, so you lose them. If you set up a series of 100 images there's a good chance you'll wind up with 15-20 at most. So you need to set your interval time to be shutter speed plus 1 second and round down (i.e. 2.5 second shutter can work with a 3 second interval).
It's way too complicated and I have no idea why it's done this way.
I use a Vello ShutterBoss wired remote for this stuff. The interval timer on it is a LOT easier to deal with. Frankly, if you want a bunch of images one after the other just set your exposure, put your camera on Constant High/Low (won't matter for long exposures) and just use the shutter button lock on the remote. It'll keep firing one after the other until you turn it off or fill the card. The D7100 has a small buffer but it should have plenty of time to clear in between shots.
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Thanks. I plan to shoot lightning at night. For that, I want the shutter open as much as possible, and since it is night, I can leave it open for seconds at a time, and have done this with my current inferior camera. From my reading, I would have to disable the long exposure noise reduction for the D7100, and use alternative post-processing noise reduction if required.
BackdoorArts
Senior Member
If you're trying to get lightning you can always just get a Nero Trigger rather than replace the camera. It'll trigger with the lightning so you're not just firing away hoping for a hit. It also triggers on sound and motion when used with a laser pointer. I use mine all the time for the last two. Funny, because I bought it for lightning and ever since we've had an almost overwhelming lack of thunderstorms.
As for Long exposure NR, I never use it and have never had to clean it up in post. I don't do a lot of night photography and when I do I don't shoot much more than 5-8 seconds. My understanding is that it's relatively easy to clean up in post using Photoshop and an exposure of equal length taken in complete darkness (i.e. lens cap on and a cloth over the eye piece).
As for Long exposure NR, I never use it and have never had to clean it up in post. I don't do a lot of night photography and when I do I don't shoot much more than 5-8 seconds. My understanding is that it's relatively easy to clean up in post using Photoshop and an exposure of equal length taken in complete darkness (i.e. lens cap on and a cloth over the eye piece).
