[HoutHans]

Hello Pentaxians,

I'm probably doing something really stupid, but I can't get this JJC thingie to work the way I want it to work. I want to use it as an external intervalometer for my K-50. I've set the camera to Bulb and set the interval to 10 seconds and for some reason the pause between the two exposures is ten seconds, whether I set the interval at 3 or 13 seconds. Can anyone help me out with this? The exposures are ten seconds, so that works

All the best,
Hans

[UncleVanya]

I’m not sure what model you have. But page three of this manual for a JJC timer suggests that the interval must be longer than the actual exposure and the interval is measured from the start of each exposure.

So in theory 13 seconds with a ten second exposure should have given you 3 seconds between exposures. Less than 10 seconds shouldn’t work correctly.

But clearly your experiences are not matching this. Post the exact model info and I’ll try looking around. Also post what the k-50 bulb settings are please.

[HoutHans]

Thanks for the quick response: the model says JJC TM Series, timer remote switch. Nothing more. The thing seems fairly generic. I have Bulb mode set to 'Mode 1: Press and hold shutter release button for exposure. Releasing button stops exposure'. I hope this helps. I started out with the interval time set from the end of the exposure, but that really messed it up. Setting it to include the exposure time, however, gets me an interval time that is way too long.

[AstroDave]

Don't forget that it takes a second or so for the camera to finish an exposure before it can take the next one. If you are asking for continuous 10-second exposures (i.e. your intervalometer just puts out a camera command every 10 seconds), every other one might be skipped.

[Not a Number]

So in theory 13 seconds with a ten second exposure should have given you 3 seconds between exposures. Less than 10 seconds shouldn’t work correctly.

PK_tether works the same way. Took me a few tries to realize this.

[UncleVanya]

I didn’t link the manual!

https://www.manualsdir.com/manuals/372475/jjc-tm-series-multi-function-timer...e-control.html

[kypfer]

The other factor to consider is that if you've got Noise Reduction enabled, once you get above a certain limit (30sec @ ISO400?) the camera takes the same time again to perform the noise reduction.
So a 10sec exposure can take at least 20sec plus the writing time if the sensitivity is too high!

[UncleVanya]

The other factor to consider is that if you've got Noise Reduction enabled, once you get above a certain limit (30sec @ ISO400?) the camera takes the same time again to perform the noise reduction.
So a 10sec exposure can take at least 20sec plus the writing time if the sensitivity is too high!

Noise reduction and long exposure noise reduction are separate settings. Iso is also not a factor on the long exposure noise reduction- it is kicked on by the length of the exposure. You can disable and manually take a dark frame of your own for post processing later if many frames are to be taken in the same conditions, otherwise I suggest leaving it on. It reduces sensor heat related noise by taking a dark frame and subtracting the noise from the exposed one.

[HoutHans]

Thanks, all. I've disabled noise reduction and long exposure noise reduction, so that's not it. I'll try again and see whether this is just some stupid error on my side.

[HoutHans]

It gets better. On my K-5 the thing works like a charm. Perhaps that K-50 is nearing the end of its life .....

[disasterfilm]

If you want back-to-back frames at 10 seconds with no gap, there's a better way to do it than to depend on an intervalometer synching its trigger with your camera's exposure ending.

Flip your settings to pure manual, dial in your frame with a 10-second shutter speed, set your drive mode to "Continuous" (high/medium/low should all work fine), and when you're ready just lock the shutter button on the intervalometer down.

It'll shoot 10-second frames, back to back, with almost 0 gap in between until either you stop it or the battery dies.
If you're shooting star trails, this is the best way to minimize those gaps between stars on successive frames.
If you do this on a KP or K-3iii with the electronic shutter mode engaged, it's pretty much a 0.0 second gap between frames.

I shoot a ton of timelapse, and for static light conditions at night, or ND-filter assisted daytime long exposure timelapse, this is the exact method I use (with shutter speeds chosen precisely for intended effect).

[HoutHans]

Hi Disasterfilm,

Thanks for thinking and helping. I'm not sure whether this will allow me to expose longer than 30 seconds (which is what I'd like to do for astrophotography). The odd thing is that it works like a charm on the K-5 and refuses to work on the K-50. I'm now trying to tether the K-50 so that I can control the shutter from an external computer.

All the best,
hans

[disasterfilm]

Hi Disasterfilm,

Thanks for thinking and helping. I'm not sure whether this will allow me to expose longer than 30 seconds (which is what I'd like to do for astrophotography). The odd thing is that it works like a charm on the K-5 and refuses to work on the K-50. I'm now trying to tether the K-50 so that I can control the shutter from an external computer.

All the best,
hans

Ah, OK. 60-second intervals don't fit to that strategy. If you can be satisfied enough with 30s frames I'd say that'll be the way to go.

Here are some other things to try if you want to give your initial setup attempt another spin:
- Make sure you've switched your camera to manual focus mode.
- Be sure to disable automatic image review (you've probably already done this).
- Set the drive mode of the camera to "continuous", even if you're relying on the intervalometer timer (and not the burst-mode shooting).
- You may have a quicker recovery interval between successive frames with the camera set in Live View mode or the conventional viewfinder. I don't have a K-50 so I can't verify which.