Can't Remember!

[Astrosurf]

You would have thought I'd have learnt that I must write things down with my dreadful memory and particulary with having very little memory for faces!

One of you will remember who you were!

I was talking to one of the instructors, can't remember who, about why, when taking a series of timed photos with my EOS and programmable shutter release, that every other photo was dark. The explanation was so obvious at the time I didn't write it down! It was something to do with the camera or timer shortening the exposure for some reason.

Can someone remind me what it was?!

Also, I took notes about my programmable shutter release which I'm not sure about. I was told to set it as follows:

Delay: 5s

Long exp example: 5 mins

Interval: has to be longer than the exp to allow the camera to record = 30 Mins - seems a bit long!

Is that right?

Alexxx

[SlipperySquid]

The interval is to let the camera cool 30 seconds, more if you have the time, just to let the ccd cool a bit so as to reduce the amount of hot pixels.

[Astrosurf]

I can't read me own writing!

I rediscovered the answer to the previous question I think. It's the Long Exposure Noise Reduction setting on the camera.

Ta muchly!

[Photosbykev]

without the LENR and High Iso NR turned off the camera takes the dark frame automatically which effectively doubles the time the camera takes for an image and is then ready to shoot again.

the interval setting should = exposure time + write to card time (2 seconds) + cool down time (whatever you choose)

[Astrosurf]

Sorry if I'm being thick, but why is the interval so long? I have the LENR turned off.

I haven't come across High Iso NR. I'll have to check it out.

[Photosbykev]

Sorry if I'm being thick, but why is the interval so long? I have the LENR turned off.

I haven't come across High Iso NR. I'll have to check it out.

The remote control sends a short start pulse to trigger the camera after each interval time you set. If you set the interval too short the pulse will be sent but the camera won't be ready so it will ignore it.

for example

5 second exposures and assuming the camera takes 2 seconds to write the image to the card before it is ready again.

so if you set the interval to 6 seconds the camera will ignore the 2nd trigger pulse because it takes 7 seconds (5 + 2) before it will be ready to accept the pulse.

the 2 second write time will depend on the camera and cards you use but 2 is a safe value for most users.

[Astrosurf]

Oh I get it! I was mis-understanding the exact meaning of 'interval'. From what you're saying it's the interval between pulses (start of one exp to start of next exp), not the interval from the end of the exposure to the beginning of the next exposure.

I thought that you had to wait for the whole exposure time between exposures!

Many thanks.

[Dave]

Oh I get it! I was mis-understanding the exact meaning of 'interval'. From what you're saying it's the interval between pulses (start of one exp to start of next exp), not the interval from the end of the exposure to the beginning of the next exposure.

I thought that you had to wait for the whole exposure time between exposures!

Many thanks.

Hi Alex

It will depend on the handset you have. Some you need to set for the length of exposure and add the interval between, others you just set the interval.

Dave

[Photosbykev]

Hi Alex

It will depend on the handset you have. Some you need to set for the length of exposure and add the interval between, others you just set the interval.

Dave

very true and will be necessary when using Bulb mode where the remote is controlling the length of exposure as well as the interval

[Astrosurf]

Yes, it's also controlling the length of the exposure.