KenY Loc: Glenside, Pa

I was out last night trying to get some star trails with my Canon EOS T6.

I set it to BULB and used an intervalometer to shoot 1, 2 and 4 minute exposures. I was also using the Canon EOS "tethering" utility connecting the camera to a laptop so I could see a quick review of the shot. Also, it was easier to focus using the laptop rather than the viewfinder or LCD screen on the back of the camera.

After the shot completed, it took roughly the same amount of time after the shutter closed before the "BUSY" message disappeared from the LCD screen and the quick review showed up on the laptop. So, on a 1 minute exposure, the camera stayed busy for about a minute, for a 2 minute exposure, it stayed busy for about 2 minutes, and so forth.

I have a Class 10 8Gb SD card in the camera so it should write the file quickly. It doesn't take long for the usual fractional-second exposures. The size of the RAW file would, I think, be the same.

Can anyone tell me why this is happening, and if there is a setting that needs to be changed to remedy. Eventually, I'd like to shoot multiple exposures with a short delay between shots, but this delay is prohibitive of any future plans.

Any help from this community would be appreciated.

Thanks.

RichardTaylor Loc: Sydney, Australia

Do you have long exposure noise reduction activated?
If so then turn it off.

Haydon

Bet you nailed it. I fell into that trap many years ago when the busy light was on for 60+seconds. Found that gremlin in my manual and it remains turned off on all my cameras since. I apply noise reduction in post only now. It gives far more control.

MtnMan Loc: ID

You may not want to turn it off but need to recognize that the way long exposure noise reduction works is to take a mirror down exposure the same duration as the exposeure and subtract it.

speters Loc: Grangeville/Idaho

Did you have any long exposure noise removal set? That would take about the same time to remove noise, as the exposure itself!

KenY Loc: Glenside, Pa

Thanks for the suggestions, everybody. It certainly sounds like this is what is going on here, but ... I was not able to find Long Exposure Noise Removal for the Canon Rebel T6/D1300. I even searched online and I found instructions for Canon cameras, but my model doesn't have this setting.

Anyone know how to disable it on the T6/D1300?

RichardTaylor Loc: Sydney, Australia

According to the PDF (intruction manual) it is on Page 262 under C.Fn-4 (Custom function menu)

(I do not own this Canon model)

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

Well found. Mr Google can help, as can a download of the manual: http://gdlp01.c-wss.com/gds/8/0300022698/02/eos-rebelt6-1300d-im2-en.pdf

Sounds like it is now time to experiment with the actual camera...

KenY Loc: Glenside, Pa

Wow! I already had the PDF full manual, but talk about burying something deep in the menu hierarchy! I found it thanks to Richard Taylor, and was able to disable Long Exposure Noise Reduction.

THANKS SO MUCH. I APPRECIATE IT.

RichardTaylor Loc: Sydney, Australia

Glad to help out.

kymarto Loc: Portland OR and Milan Italy

You may find you want it on after you see your first long exposure without it, but go ahead and try. Sensors have a lot of amp noise that results in color blooming in the dark areas.

Allen D S

I found that long exposure NR made the difference between usable and not. That was on a Nikon D90. I have not tried any night photography with my D500.

Whuff Loc: Marshalltown, Iowa

Thanks for posting this question. I've seen the samething with my T3i but just assumed that was how it worked. I'm going to try it with the noise reduction turned off to see what the results are. The T3i is not very good in low light situations anyway so it may create worse exposures without the NR but I dislike the extended time required to process following the exposure so it may be worth trying.

Walt

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

I had almost the opposite reaction. I don't do a lot of low light work, so just switched from 'auto' to 'on' so that I can see what happens. It's an easy setting to change once you know that it is there, as with most things. On the other hand for low light work I can always stick one of my old (adapted and chipped) wide aperture manual focus lenses (FL 55mm f/1.2 or FDn 135mm f/2) on it. Autofocus isn't that great in the dark anyway!

Lots of ways to skin a cat, as they say!