Time to end the mirror slap myth

[Mark Layne]

I trust that beer is Moosehead?
Mark

Don
Remember the rocket launching site planned for Cape Breton. It now occurs to me that might be why they wanted to borrow my Davis and Sandford
Mark

 

[pnance]

I think its a testing flaw! The penny is turned the wrong way. It needs to have the flat side to the front of the camera. Positioned as shown the movement would be to rotate the coin. Not push it sideways.

Paul

 

[Q.G.]

I think its a testing flaw! The penny is turned the wrong way. It needs to have the flat side to the front of the camera. Positioned as shown the movement would be to rotate the coin. Not push it sideways.

No matter what or how: it didn't move.

But you're kidding, aren't you?

 

[JRJacobs]

My Hasselblad has a slappy mirror. Come to think of it, so does my Pentax 67ii. Also, I just remembered my RB67 occasionally wakes the dead. I have a friend with a Bronica - when he presses the button it makes a sound like "ker-slap".

Never tried balancing a penny on any of them - can't quite figure out how that will improve my photography.....

 

[Steve Smith]

In some cameras the mirror coming to rest at the top triggers the shutter to fire.

A lot of cameras go through the firing sequence with the end of each operation triggering the next operation.

e.g. Pressing shutter starts the mirror going up and closes down aperture. Mirror up starts first shutter curtain travel. End of second shutter curtain travel releases mirror and opens aperure.

I found this out with my ETRS when I replaced the mirror up damping foam The first bit I used was a bit too thick and the mirror did not go up far enough to trip the shutter.



Steve.

 

[Sirius Glass]

In some cameras the mirror coming to rest at the top triggers the shutter to fire.

A lot of cameras go through the firing sequence with the end of each operation triggering the next operation.

e.g. Pressing shutter starts the mirror going up and closes down aperture. Mirror up starts first shutter curtain travel. End of second shutter curtain travel releases mirror and opens aperure.

I found this out with my ETRS when I replaced the mirror up damping foam The first bit I used was a bit too thick and the mirror did not go up far enough to trip the shutter.



Steve.

Replacing the foam or replacing the bump stops can reduce the vibrations. Just another reason to have a CLA every few years, it not every year. YMMV.

Steve

 

[Joe Grodis]

Try making some enlargements of Moon or night time stars with Mirror slap. I've NEVER had good ones with mirror slap.

 

[Sirius Glass]

Try making some enlargements of Moon or night time stars with Mirror slap. I've NEVER had good ones with mirror slap.

Those photographs require a tripod for sharpness. The Moon is best done on an equitorial mount. Any time exposure requires a mirror lock up. We are talking about typical uses.

This thread is aimed at the whiners who complain about mirror bounce at 1/500 second.

Steve

 

[Thomas Bertilsson]

Let's take a different approach.

The camera works both hand held and on a tripod, with or without mirror lock-up. I am sure that there are ways to measure the effect or not locking up the mirror, and when the camera is on a tripod, it doesn't make any sense not to lock the mirror up, unless you're shooting moving objects and have to track something in the viewfinder. It's easy enough to do.

If used hand held (I do this a lot in portraiture), the camera handles VERY nicely. In the Hasselblad camera literature, there are explanations and recommendations of how to hand hold the camera. While hand held, it is impossible to use the mirror lock-up in my opinion, and it may not even be necessary. I've made portraits on Portra 400 and Tri-X film that I've enlarged to 14x14" and they are tack sharp.

Re: The Moon. I shoot the moon using the Sunny 16 rule. So with ISO 400 film I can photograph it at 1/500s at f/11 with Tri-X film. Locking the mirror up might help.

How sharp do you need? That's the fundamental question that underlies all of this debate.

If the engineer gods at Hasselblad didn't want us to use mirror lock up, they wouldn't have provided the button.
Likewise, they are equipped with not one, but two tripod screws.

The flower was photographed using the set up in the B&W shot. Mostly I used MLU, but can't say whether it was used on this particular shot or not.

 

[Steve Smith]

Any time exposure requires a mirror lock up. We are talking about typical uses.

To a point. Above a few seconds, it's not going to make much difference.

This thread is aimed at the whiners who complain about mirror bounce at 1/500 second.

Good point!



Steve.

 

[Prest_400]

Uhm, my OM1 doesn't pass the test (at least how I did it). I put a 20cent coin between the lens cap and the fron of the lens. And it fell. Maybe I pressed the shutter button too hard, speed was 1/60

 

[keithwms]

Uhm, my OM1 doesn't pass the test (at least how I did it). I put a 20cent coin between the lens cap and the fron of the lens. And it fell. Maybe I pressed the shutter button too hard, speed was 1/60

Try with the timer.

If that fails, then simply glue the coin to the camera and be happy.

 

[2F/2F]

Excellent. Now all that is left is to scientifically make the correlation between falling pennies and blurry pictures.

 

[E76]

I just tried the penny trick with my Hasselblad sitting atop a dresser about 18x34" in size. The penny fell over every time.

It looks like there may be some correlation between the size of the surface the camera is resting on and the absorption of vibration.

 

[Prest_400]

Try with the timer.

If that fails, then simply glue the coin to the camera and be happy.

Now It passed the test.
I just pressed too hard maybe
Bah, It can take sharp pictures at 1/8 handheld (with good support)