1100D mirror lock up.

raymo · #1 11-09-2014, 08:07 PM

After hunting high and low through the user's manual, I have come to
the conclusion that one way Canon have found to keep down the
price of the 1100D, is to delete the mirror lock up feature found on all
it's predecessors since the 350D. It has lock up for Live View and manual
sensor cleaning, so what have they saved by deleting it as a user's feature. I hope I'm wrong, and that it is hidden in there somewhere.
raymo

doppler (Rick) · #2 11-09-2014, 08:54 PM

I don't think its there, I searched for ages on my 1100d menu settings and mirror lock only seems to work on live view or with the laptop conected as an auto feature. My 450d has the mirror lock in the menu settings.
Rick

MrB (Simon) · #3 11-09-2014, 08:57 PM

Yup. I just turn on live view a few seconds before I take a shot.
I've never really found it to be a problem anyway on a solidly mounted scope.

Camelopardalis (Dunk) · #4 11-09-2014, 08:58 PM

Nah it's not there. As you guys have guessed, you have to either hit the shutter release with live view on (and warm up your sensor some more) or use the laptop.

raymo · #5 11-09-2014, 09:06 PM

It never occurred to me that as lock up is only needed for very short exposures, maybe Canon think that using Live View is the way to go.
I suppose though, that after taking a largish number of shots, the sensor would heat up significantly, as was mentioned.It would have been nice if Canon had put something in the manual about it. Thanks for the replies
fellas.
raymo

MrB (Simon) · #6 11-09-2014, 09:48 PM

I've not noticed the sensor heat up, for me live view is only on for 5 to 10 seconds at the start of my imaging run(to check focus) and then there's only about 2 or 3 seconds between exposures, most of which is the last exposure image review before live view kicks in again for a fraction of a second before the shutter opens again. It doesn't get enough time to heat up. Tho it might if the exposure lengths are very short.

Camelopardalis (Dunk) · #7 11-09-2014, 09:58 PM

Weird, my screen stays on when I try it

raymo · #8 11-09-2014, 11:27 PM

So does mine.
raymo

doppler (Rick) · #9 12-09-2014, 12:16 AM

My screen only stays on with the bulb setting, then a counter is displayed on screen, but with 30sec or less it turns of during the exposure

MrB (Simon) · #10 12-09-2014, 12:40 AM

Yes your screen shows the timer, but that is not live-view.
Besides, the timer screen is on in bulb mode whether you use live-view or not.

The sensor gets hot in live-view because it is in video mode and is constantly being read from, this means all the amplifiers and shift registers and other electronics are powered up continuously.
A timed exposure is different, the amplifiers and most other electronics on the sensor are turned off, the sensor uses very little power while being exposed, until you tell it to stop the exposure and everything powers up to read out the pixels and amplify/convert the signals etc.

raymo · #11 12-09-2014, 11:37 AM

Thanks for the info Simon.
raymo

Regulus (Trevor) · #12 13-09-2014, 03:49 PM

It was a feature I was intent on getting when I was shopping and ended up with the EOS600D for that and the reticulated view screen. It wasn't mentioned as a feature on the 1100.
I was reading about it this morning before I saw this thread because the Luna shoots I took arn't as sharp as I'd like and I thought ML might help. So, I was interested to read in the book that ML is almost a must for long telephoto lenses and Macro shots. That explains the blurred fungi shots. Most of these are longer than 1/2sec and up to 2sec and so there is time for a fine vibration to play out when the shutter fires.
I look forward to trying it.
Trev

OzEclipse (Joe Cali) · #13 14-09-2014, 11:42 AM

These comments apply very generally to all SLRS.

The mirror slap on an SLR causes a damped vibration that damps out after around 20ms or 1/50s. There is some variation of amplitude and damping time between camera models but 20ms is a reasonable average.

A 1/50s exposure or 1/60s is the closest on most cameras is obviously going to capture a large % of the vibration amplitude. There is a small delay between pressing the shutter release and the shutter opening. Part of this is a delay between the mirror flip and the shutter opening that cuts out part of the vibration. Mass market demands minimal delays between shutter press and exposure so manufacturers can't allow too big a gap to keep the delay to a minimum.

Faster exposures and slower exposures are progressively affected less and less.

If the vibration lasts for 1/50s and you make a
1/30s exposure, 60% of the light will be subject to the vibration.
1/15s exposure, 30% of the light will be subject to the vibration.
1/8s exposure, 15% of the light will be subject to the vibration.
1/4s exposure, 8% of the light will be subject to the vibration.
1/2s exposure, 4% of the light will be subject to the vibration.
1s exposure, 2% of the light will be subject to the vibration.
2s exposure, 1% of the light will be subject to the vibration.
and so on.

As exposures get longer on fainter objects, the vibration is progressively underexposed.

As you go faster and faster, the exposure only captures smaller and smaller parts of the vibration.

Shutters still impart some vibration. Mirror lock up(MLU) is useful for some things. For a single manual astronomical exposure, the top hat or black card method is the most effective. For a computer controlled set of subs then there is some merit to use of MLU however longer 30+s subs should not show much effect from mirror slap.

The only application I can think of where you would make multiple subs in the 1/125-1s range are lunar and solar eclipses.

Obviously MLU is worth using if you have it, but a camera without is still highly useable particularly with subs longer than 1s.

Joe

OzEclipse (Joe Cali) · #14 14-09-2014, 12:05 PM

Quote:

Originally Posted by Regulus

I was reading about it this morning before I saw this thread because the Luna shoots I took arn't as sharp as I'd like and I thought ML might help. So, I was interested to read in the book that ML is almost a must for long telephoto lenses and Macro shots. That explains the blurred fungi shots. Most of these are longer than 1/2sec and up to 2sec and so there is time for a fine vibration to play out when the shutter fires.
I look forward to trying it.
Trev

Trevor,

The mirror slap is causing vibration directly in the shutter plane and is independent of focal length. Mirror slap won't move a large telephoto lens around on a solid tripod. The most important thing in long focal length and macro shooting is a solid tripod. Movement of the subject can also cause blur in these shooting situations.

Joe