Leaf vs FP shutter for Hassy low light?

[olwick]

Hi,

I was reading a site someone had made about Hasselblads and came across this statement:

For some applications, especially for low light photography, it's better to have a shutter in the body instead of in the lens.

Referring to the 500 series vs the 2000 series.

For the life of me, I can't figure out why that would be. I'd think that leaf shutters would be much better for low light.

Thoughts?

Thanks,

Mark

 

[rwboyer]

Personally I think the only rationale for this is that SOME of the F lenses w/o the shutter are a stop faster than the C/CF type lenses of the same focal length.

RB

 

[olwick]

Ahh, that would make sense. I do a lot of long exposure stuff, so that would matter to me.

 

[keithwms]

I don't think leaf shutters are intrinsically better in low light, on the contrary, I would say they are more advantageous in ample ambient light when you want to fill and thus can make use of the fast synch.

 

[Q.G.]

Leaf shutters cause less vibrations than a focal plane shutter.
So if you worry about shake at longer speeds, a leaf shutter would be advisable.

Apart from that, no reason i can think of to prefer one over the other for long exposures.

 

[Sirius Glass]

I always use a leaf shutter when using my Hasselblads, but that is a reflection of the fact that I do not have a Hasselblad with a focal plane shutter.

Steve

 

[Q.G.]

Then you should get you one.
Nice lenses... More possibilities...

 

[Q.G.]

Personally I think the only rationale for this is that SOME of the F lenses w/o the shutter are a stop faster than the C/CF type lenses of the same focal length.

I think that's it too.

I'd change "SOME" into "MOST" though.
Only one of the 7 shutterless lenses available is as 'slow' as the shuttered counterpart.

 

[rwboyer]

I think that's it too.

I'd change "SOME" into "MOST" though.
Only one of the 7 shutterless lenses available is as 'slow' as the shuttered counterpart.

I am a glass is half empty kind of guy.

Kidding - why the F did everyone else seem to read the quoted source backwards? Whoever was quoted did say LOW LIGHT NOT SLOW SHUTTER.

RB

 

[Q.G.]

Perhaps because one very rarely gets to use a shutterspeed of 1/2000 in low light conditions?

 

[BetterSense]

Leaf shutters cause less vibrations than a focal plane shutter.

[citation needed]

 

[Q.G.]

I'm too lazy to search for one. (May do so perhaps later. Meanwhile, you could do so too. )

This thread being about Hasselblads, i can tell you from experience that the focal plane shutter models do indeed give a larger kick than the leaf shutter models.
You can cite me on that.

But i will also tell you why it is.
Leaf shutters move (typically) four or five small metal blades, not large curtains.
Vibration is caused mainly by the sudden stop these blades or curtains come to when they reach the fully open position (also when they crash into the fully closed position, but then noone cares what they may or may not cause).

The reason why these moving blades cause less vibration than the moving curtains is because the five blades move in five different directions. The momentum is divided and dispersed. The blades (literally) do not join forces.
The curtain of a focal plane shutter moves in one direction only. The momentum has a single direction.

(Leaf shutters may also involve fewer moving parts - i.e. a less complicated mechanism - than focal plane shutters. The blades or curtains of course are not the only things moving when you fire a shutter. That too will have an effect.
But that is not a fundamental difference, but depends on the particular mechanism used instead.)

 

[rwboyer]

I'm too lazy to search for one. (May do so perhaps later. Meanwhile, you could do so too. )

This thread being about Hasselblads, i can tell you from experience that the focal plane shutter models do indeed give a larger kick than the leaf shutter models.
You can cite me on that.

But i will also tell you why it is.
Leaf shutters move (typically) four or five small metal blades, not large curtains.
Vibration is caused mainly by the sudden stop these blades or curtains come to when they reach the fully open position (also when they crash into the fully closed position, but then noone cares what they may or may not cause).

The reason why these moving blades cause less vibration than the moving curtains is because the five blades move in five different directions. The momentum is divided and dispersed. The blades (literally) do not join forces.
The curtain of a focal plane shutter moves in one direction only. The momentum has a single direction.

(Leaf shutters may also involve fewer moving parts - i.e. a less complicated mechanism - than focal plane shutters. The blades or curtains of course are not the only things moving when you fire a shutter. That too will have an effect.
But that is not a fundamental difference, but depends on the particular mechanism used instead.)

OG

While your information is entirely accurate and all coated in wonderfulness - completely irrelevant for the OP's question which was if you read it again - wanting an explanation for some anonymous person that stated that the F shutter was BETTER for low light - NOT the reverse.

My speculation was that the original author probably was making a reference to the fact that almost all F lenses are a stop faster than their C/CF counterparts.

RB

Ps. in real life the mirror and second curtain are just as big a vibration producer than the F shutter so at the end of the day unless you are pre-releasing it don't matter much.

 

[Q.G.]

OG

While your information is entirely accurate and all coated in wonderfulness - completely irrelevant for the OP's question which was if you read it again - wanting an explanation for some anonymous person that stated that the F shutter was BETTER for low light - NOT the reverse.

Indeed.
But if you read the thread, you'll find the above was in answer to Bettersense, not the OP.


It's not irrelevant though, since it is directly about the fact that if anything, the opposite of what the OP was told is true: leaf shutters would be better than focal plane shutters.

]My speculation was that the original author probably was making a reference to the fact that almost all F lenses are a stop faster than their C/CF counterparts.

I agree (and have done so before).

Ps. in real life the mirror and second curtain are just as big a vibration producer than the F shutter so at the end of the day unless you are pre-releasing it don't matter much.

That's right

 

[keithwms]

I don't see any slap from focal plane shutters... because I use RFs or SLRs with MLU Recently I did some available light stuff on a monopod with an rz and 110/2.8... no slap. And of course that mirror gives about a 1 or 2 on the Richter scale :rolleyes:

A lot of available light work is done with FP shutters. Leica RFs come to mind? Even on SLRs without MLU, slap actually isn't an issue at long exposures, it's the intermediate ones that are iffy. E.g. slap might really get you at around 1/25 or 1/60 (though this depends on a lot of things including how the camera is braced, so despite what anyone may say, it really does depend....). At 1/8 or slower, I doubt slap enters the picture in any meaningful way. Right about now is when somebody shows a penny balanced on a hassie as if that proves anything. I am just saying everything matters and you have to sort through what matters most to you. Does superduper maximum critical sharpness matter to you? If so then act accordingly.

Again, the #1 attraction of leaf shutters is their fast synch, which you typically exploit in strong ambient light, not in low light. The leaf shutter synch is now getting very fast; some new LS lenses from Mamiya allege 1/1600. That means it would be possible to shoot at f/2.8 with fill flash in broad daylight. E.g., suppose you want to do a bride or a skateboarder in broad daylight. (Hmm that last sentence didn't come out quite as I intended )

Anyway, I suspect the real reasons why Mamiya is introducing such things are: (1) the shallow DOF fad and (2) the base ISO for the digital backs actually isn't low enough to work this way: it is a common problem with 35mm DSLRs that somebody wants a longish exposure or wants to fill while also keeping very limited DOF. the easiest solution, available to film users, is to simply use a very low ISO film and/or pull like nuts. But with digital the base ISO is typically no lower than 25, and nowadays it is getting much higher because people demand better low light performance, hence larger photosites hence higher base ISO. You might think just cut the signal but it's not so easy, when a site gets saturated that's it, it's saturated, and the only practical way around it is to slap a ND on the lens.

Anyway to make a long story short, there are some 1/1600 synch LS lenses from Mamiya, check 'em out.

Of course, what I am saying (and what others are saying too) is very broadbrush and one simply needs to do some trying-out to find the best tool. There really is no acceptable shortcut to learning things for yourself.

 

[fschifano]

Maybe the answer is really simple. For long exposures, 1 second or greater, any vibration caused by moving parts is minimal. The vibration time is an almost insignificant part of the total exposure time and it won't affect the image enough to be noticeable under many circumstances. Between about 1/15 through 1 second, it might make more of a difference because the vibration time is a more significant portion of the total time. The faster lenses available with the FP shuttered Hasselblads can make a big difference. Even if you don't shoot wide open, and I rarely do, the brighter viewfinder makes focusing and composing a lot easier.

 

[msage]

Don't believe every thing you read, especially on the internet.

Hi,

I was reading a site someone had made about Hasselblads and came across this statement:



Referring to the 500 series vs the 2000 series.

For the life of me, I can't figure out why that would be. I'd think that leaf shutters would be much better for low light.

Thoughts?

Thanks,

Mark