NWPC - Tools

We hope to create and collect some tools that might be useful to our members and guests when creating slideshows

Shows often have more "punch" when the progression of images is timed to the music.

When you are doing this kind of synchronization, a good place to start is to align the start of a transition to the accent beat in your music. The slidetime for an image (or "slide") is then the remaining beats in the measure.

For a more relaxed pace that still keeps time with the music, try allowing 2 measures per slide, but still just one beat for the transition.

This calculator gives you a head start in knowing how long your transition and slide times should be. Tap out the rhythm of your music using the Beat Calculator, then use that average BPM and the metre of your music and a transition style to generate the timings. You don't have to tap out the entire song! just enough to get a good feel for the average beats per minute.

Once you align the starting transition of the first slide to the beats, most of the rest of the slides should line up. No music is perfect, so you will still have to tweak the odd slide or two, but that is still a lot faster than hand tweaking every slide!

If you already know your BPM (e.g. your stock music site often gives you this information), you can just enter it directly. If your music changes tempo several times, then obviously you will need timings for each passage in your music.

An example of this method can be seen in a show on this site: Harrisand used music math to get the rough timing. The author then only had to tweak about 6 slides to get the right fit.

BPM Calculator

Press "start" and then tap on your keyboard to count beats.
When you have counted out the beats to your music,
press "done".

Average BPM:

Current tap rate:  

Number of Taps:

Slide Timing Calculator

Average BPM:
Music Metre:
Transition Beats:
Slide Time: 
Transition Time: 
1 beat =  
1 measure =  

Time Lapse Photography Calculations

Below are 3 "calculators" to help those answer common mathematical questions for time lapse work. Determine the question you need answered, plug in your "input" values, press the button for the answer

Time Compression:

What interval should I use to compress my event time down to a specific playback time?

Playback Duration:

I shot an event at a set interval. How long will my video playback be?

Constrained Playback:

I want a video of a certain length, shot at a given interval. How long of an event will I have to shoot?


The duration of time you are shooting. A long event could be many hours (6 hours = 240 minutes)
The length of the final video play back.
The time between shutter releases, expressed either as time (hh:mm:ss) in these calculators. For a generated interval, this may be a sub-second shutter speed (1/4 means one quarter second (or 0.25 seconds). Note: Many timelapse intervalometers (aka timers) don't do sub-second intervals.
FPS (Frame rate)
The rate at which the final video plays back. Expressed in terms of frames per second (fps). The most common values used in video are: 24 (film), 29.97 (NTSC DVD style video), and 30 (modern video). To save data, some websites go as low as 15 fps, about the slowest you can display video and have the human eye see it as motion rather than distinct frames.
All times (intervals, playback, event duration) are expressed as hh:mm:ss — so 00:43:20 is 43 minutes and 20 seconds. If you enter a time without colons, the calculations will assume you mean seconds. You can enter numbers "larger than normal" in a field and values get calculated appropriately, so 75:00 means 75 minutes or 1 hour, 15 minutes. So you could enter "1:00:00", "60:00" or "3600" — they all mean "one hour".