'Busy' for long time between captures

[lrhodes@huonit.com.au]

Hi there, just checking if this is normal or if something wrong at my end. If I take for example a 30 sec exposure with my Canon 700D (T5i), it shows Busy for 45 - 60 seconds after the shot, then 'downloading' only for a 2 seconds or so. So it ends up being up to 90 secs per 30 sec exposure, does that sound about right? Have a good speed laptop, good usb cable, fast memory card etc. Have tried turning off AWB, trying RAW only, Jpg only, storing on camera, all seems to take exactly same amount of time.  60 sec exposures take longer again, around 90 secs added for 'busy'. Appreciate any help or confirmation that this is just to be expected. Cheers

[astroman133]

Do you have long exposure noise reduction turned on in the camera?  If so, the camera takes a dark frame for each light frame. So a 60 second light frame is followed by a 60 second dark frame. The dark frame is applied before the image is downloaded!