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Author Topic: Sharper lens LS 150 or Mamiya 150 ? + What is sharper, LS or FP ?  (Read 2016 times)

antoinerose

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Hello,
Could anyone tell me:
- what would be the sharpest lens between the Mamiya Sekkor 150 and Schneider 150 ls (Can't find any MTF)
- Is the LS lenses in general supposed to be more sharp then the Focal pane shutter version when shooting handheld without mirror lockup ? In other words is the LS shutter less prone to add vibration vs the focal pane, if we compare LS vs FP ?
It's for shooting handheld from helicopter. I'll add a kenyon gyro but need the best possible lens for this purpose.
Thanks for your answer !
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FredBGG

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Re: Sharper lens LS 150 or Mamiya 150 ? + What is sharper, LS or FP ?
« Reply #1 on: August 24, 2012, 12:33:34 pm »

What will you be shooting....?

IF you don't need the high speed flash sync I would stay away from the Schneiders.

The Mamiya 2.8D is a brilliant lens. One of the very best medium format lenses in production.
Not only is it sharp, it also has very nice bokeh and immediate focus fall off is very nice too.

The only thing that may be a problem for you is the vignetting the 150mm 2.8 has when shooting wide open.
While it is smooth and actually quite pleasant due to it being combined with the nicest bokeh on a modern 645 MFD
it could be an issue for technical photography.
It can be corrected in post, but it is a 1 stop correction so corners are "pushed" one stop.

One other important thing to consider though regarding leaf shutter or focal plane shutter is actual overall shutter release time.

While a focal plane shutter has higher top speeds the actual duration of the whole exposure is 1/125th of a second.
The shutter sort of scans over the sensor exposing a slice.At 1/4000s each pixel gets a total of 1/4000s, but they are not exposed at the same time.
This can lead to distortion with fast moving objects.
With a leaf shutter set at 1/1600s the whole exposure takes part in that 1/1600th of a second. All the pixels are exposed art the very same time.

Here is a high speed video of a focal plane shutter. You can see that the shutter at 1/1000th never fully opens, but opens a crack that then scans
over the sensor.

http://www.youtube.com/watch?v=-isRz54C_vY

Now going back to sharpness camera shake is not your only problem. A kenyon gyro will help a lot, but the chopper's rotor blast will be your main issue.
Both the low frequency noise and percussive impact of the wind will "eat" sharpness.

That is why the best results are obtained shooting from under a chopper or out of a "hole in the floor".

If you are going to do a lot of helicopter photography I would strongly recommend putting the budget towards a Nikon D800 and running it remotely in a pod system
that you can mount under the chopper. You can remote the camera with either Nikon software or Control my Nikon.

http://skyimd.com/skydslr.html

You sit safely and comfortably (well as comfortable as a chopper can be). You use real time live view. You can use VR stabalized lenses for shooting at dusk and sunset.

D800 vs IQ180:

http://www.circleofconfusion.ie/d800e-vs-phase-one-iq180/

I have also seen some amazing work shot with a pod on a small airship all remotely controlled.

Going back to the Kenyon Gyro and results with a camera.
With a Kenyon of whatever sized one you will get you will get far better results with a light camera.
That is another reason why I recommend a light D800 rather than a much heavier MFD.
Put a bigger kenyon on a lighter camera and you will fight vibration and prop percusion much better.

My cousin is a geological arial photographer. He now gets better results with his D800e plus gyro in a diy pod that he was getting
with systems 20 times the price. What's best is he flies with two systems.

Oh one other tip. Keep in mind that you do not want to have your gyros spinning with the rig receiving mechanical vibration
from the helicopter frame. It will kill the gyro in no time.  
« Last Edit: August 24, 2012, 12:47:54 pm by FredBGG »
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antoinerose

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Re: Sharper lens LS 150 or Mamiya 150 ? + What is sharper, LS or FP ?
« Reply #2 on: August 24, 2012, 04:09:40 pm »

Hello,
Thanks very much for your answer. I actually own a D800 but am not satisfied with rhe results. I'd be pleased to contact your cousin to discuss the topic.
Maybe you could send his details via PM ?
I've just printed a 9 feets shot from a P45+ (2 frames stitched) and I'm quite pleased with the results. I just want to go a step further and double the resolution with eventually an IQ 180 and a check wether the focal pane adds blur vs LS. (I own a 150mm sekkor) Very good lens but in a chopper, a bit blurry without gyro.

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Wayne Fox

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Re: Sharper lens LS 150 or Mamiya 150 ? + What is sharper, LS or FP ?
« Reply #3 on: August 26, 2012, 02:46:04 am »

- Is the LS lenses in general supposed to be more sharp then the Focal pane shutter version when shooting handheld without mirror lockup ? In other words is the LS shutter less prone to add vibration vs the focal pane, if we compare LS vs FP ?

I'm not sure there is a definitive answer.  However, even with mirror lockup the LS lenses may not provide much help as far as the focal plane shutter bounce, because mirror up does not open the focal plane shutter when using the leaf shutter, but instead opens when the exposure starts.  If the focal plane shutter vibration is the result of the second curtain closing, then I would assume the leaf shutter would have opened and closed before that, providing some benefit.  If it is from the first curtain opening, then the leaf shutter probably isn't doing much.  If it's a combination, I suppose there might be some benefit.  But the main benefit of the LS lenses to this point has been flash sync.  Rumor has the new camera Phase/Mamiya is reportedly working on would employ a system where the focal plane shutter would open when the mirror moves up in mirror up mode when using a LS lens, rather than waiting until the exposure begins.  guess we'll see (someday).

The shutter bounce while hand holding I would suspect to be pretty negligible, my logic is that hand holding is probably causing more movement than the shutter bounce anyway. 
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henrikfoto

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Re: Sharper lens LS 150 or Mamiya 150 ? + What is sharper, LS or FP ?
« Reply #4 on: September 01, 2012, 06:25:15 pm »

Hi Fred!

I am interested in the Gyro. How would this be to shoot freehand MF?
How much longer shuttertimes do you think will be possible with a gyro under the camera?

Henrik
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S@W

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Re: Sharper lens LS 150 or Mamiya 150 ? + What is sharper, LS or FP ?
« Reply #5 on: September 03, 2012, 04:39:26 am »

I did compare boty 150mm lenses during a day and personally thinks that - even if the price difference between the schneider and the Mamiya lets you (strongly) suggest that the Schneider should be better - there is no difference in resolution or micro contrast between those 2 lenses.
The Schneider has a better flare resistance thanks to its better lens shade. But this lens shade can be baught separately (500Eur here) and can also be mounted on the 150mm Mamiya (same diameter and mounting system).

The Schneider maybe has an even better bokeh at equivalent aperture than the Mam, but the difference is rather small and certainly subjective. And don't forget the mamiya can open at f2.8 when the Schneider stops at f3.5 (and the f2.8 of the mam has a smoother bokeh than the schneider at f3.5...).
The lens construction is more modern with the Schneider (metal, AF/MF selection).

But in the end, don't expect to get better resolved pictures with it (tests were made on tripod, MLU, 6 sec wait, super sharpness zone on the exact same position). The difference between both is more related to the center shutter, lens construction and lens shade.
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