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giganova
19-Aug-2020, 15:44
Sorry if this has been discussed to death already ... but I want to find a reliable & easy method to test my shutter speeds. I download an app for my iPhone that uses the widely discussed audio test, but find it completely unreliable. What am I actually looking at here? Where is the start/end of the shutter?? Example for a 1/100 s shutter speed and my best guess at the bottom image.

Is the Phochron optical tester (https://www.phochronxa.com) a better way?

https://live.staticflickr.com/65535/50246257102_b36357bf6a_z.jpg (https://flic.kr/p/2jy6cFC)Lens_Shutter_Audio_Test (https://flic.kr/p/2jy6cFC)

lassethomas
19-Aug-2020, 16:07
If you want that app to work reliably you need the small FILMOMAT PhotoPlug addition so that it works with light instead of audio.
I can measure down to 1/250 with it.
And you need an regular headphone plug on your iPhone.

Can be found here for example https://www.fotoimpex.com/cameras-accessories/filmomat-photoplug-shutter-speed-tester.html

Bertha DeCool
19-Aug-2020, 19:05
I have to agree with lassethomas; I tried to make sense of the audio-only and could not get nearly satisfactory results, even with shutters that were "quiet" enough to not introduce additional noise.
The PhotoPlug is reasonably inexpensive and, while not perfect, has yielded consistent results that have proven to be reliably accurate. It was worth it.
If you do decide to order one, mine took some time to arrive, I believe from Germany, and that was quite awhile ago, "pre-Covid".

reddesert
19-Aug-2020, 19:57
I've used the audio version of the shutter speed app. It will only be useful at speeds slower than about 1/60 or 1/125 at best. To understand the waveforms, you should start with a relatively slow speed like 1 or 1/2 sec, try that, and increase toward faster speeds, and look at what parts of the waveform stay the same and what change. Typically, there will be an initial spike, then a clack a very short time later when the shutter opens, a delay, and then another clack when the shutter closes. Different shutters have different "signatures," but for all of them, by the time you get to 1/125, it's hard to tell these phases apart. The audio also won't work on a focal plane shutter faster than the sync speed , clearly.

The light sensitive doodad is clearly a superior solution, but the audio is useful as a quick check.

ltbphoto
19-Aug-2020, 20:06
If you have an inclination towards DIY, you can build a very straightforward tester using an Arduino and a few small parts for under $20-

https://youtu.be/UwOh3da_Y8s

The video is super goofy but explains how to set up everything once you have the parts. I initially set it up using some tape and a cardboard box, later built an actual enclosure and arm - either approach works equally well.

europanorama
25-Aug-2020, 21:40
photoplug. he-Franz- told its accurate til 1/500. if smartphone has not 2.5mm plug anymore you need a cable-adapter or one without. if cable then you need-beside one for the single-beam-flashlight and second helping hand(tool for soldering). sensor must be 5-10mm from shutter. with helping hand light or sensor can be placed easily in long cameras. when sensor can be attached directly on phone one can handhold.
2. since data is stored in app and not outside(franz should improve this) it is highly avdviced to note(write down) the results or take screenshots. otherwise when app is deleted all data is gone. 3. graph must be enlarged to see details-use two fingers. instructions are very detailed, not like the one from romania where the inventor told(not knowing about the enlarging issue since he had not android) its the audio-plug in cheap device... it then sent it back.
had troubles when testing flashsynch in nikon-cams. all of them were 1 stop slower. but non flashsynch-1/125 were all accurate.
Will get phochron XA.