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-   -   Ultimate - problem with shutter speeds above 1/125th sec! (https://www.dvinfo.net/forum/alternative-imaging-methods/135519-ultimate-problem-shutter-speeds-above-1-125th-sec.html)

Gerald Loidl October 9th, 2008 11:43 AM

Ultimate - problem with shutter speeds above 1/125th sec!
 
The Ultimate should be able to handle higher shutter speeds, but mine cant handle any speeds higher than 1/125th. The main reason for me to buy the Ultimate was that shutter speeds of more than 1/2000th were advertised.
Today I messed up a shot where I used 1/250th shutter speed. The grain of the spinning ground glass was fully visible during this take and I was shocked when I just watched it on the big monitor. I used f5,6 on the 35mm lens and about f4 on the camera. The speed on the Ultimate was set to 99. The Ultimate also makes slight ticking noises when on since day one, but I hope thats normal? It could be a problem when shooting with sound on a very quiet set or soundstage though...

Any tips whats wrong with my adapter? The shutter speed problem is a real issue for me!

regards,
Gerald

Pim Hawinkels October 9th, 2008 01:50 PM

Hi i noticed the same on a friends' ultimate. the ticking noise is the rubber band that drives the groundglass, in my friends case the noise was the same, and i noticed that the rubber band is too long, so it'll stretch on and off when its on, cant really explain, just have a look yourself. if it would be tighter, the noise would be gone i think. and he also had the same problem with the shutterspeed, i think from 1/250th of a second you could see the groundglass... bye the way why should you want to adjust the speed of the groundglass? its best when its as fast as possible, always. i dont get it, with this feature. you just dont want to see the groundglass. so always put it on maximum. but on the other hand, i heard that the batteries dont last longer than a day, this way.... with the extreme, you can use them for a week....

i think if you can find another rubber band to drive the groundglass, it would be solved... maybe the letus people can help you... goodluck

Bob Hart October 9th, 2008 09:54 PM

I haven't read the claimed specs on the Ultimate. What I do know from my own disk based adaptor is that you may have asked for a bit too much from your Ultimate, if my own is anything to go by.

I hope sincerely that I have not misled you by previous reference to my own adaptor and a link to this clip in a previous "how things could be" type of post on this forum. In that post I referred to a 1/2500th sec shutter speed and f5.6 claim for my own adaptor only and offered I think a theory only that the Ultimate might be capable of this if the disk rpm was fast enough.

AGUS35APVE HIGH SPEED SHUTTER TEST REVISED EXPORT By Bob Hart On ExposureRoom

With shutter of 1/50th or thereabouts, iris of f5.6 ,you are hard up against the usable zone for most groundglasses, especially in high contrast outdoors environments.

Iris tighter than f5.6 may give you artifacts with any adaptor.

You also had f4 on the camera. This is within the sweet spot for many camcorders. There sometimes occurs an interaction between both iris settings which can provoke an artifact. Wider on the SLR lens iris and tighter on the camcorder lens iris or some added ND would have been my personal preference if the light was too bright.

Add in a higher shutter speed and to my judgement you would have been pushing the envelope.

I am not saying the Ultimate cannot do a 1/2500 sec shutter. My guess is that this would require max disk speed, a wide-open f1.4 lens and benign lighting conditions to be a reliable expectation.

As to groundglass speed. A disk does not need to be rotating very fast at all to deresolve the groundglass texture at 1/50th second shutter in ideal lighting and iris settings. My own adaptor uses a 5" or approx 125mm diameter optical glass disk at about 700rpm. The Ultimate would have to be spinning faster for high shutter speeds as the disk diameter is smaller.

For normal use in ideal circumstances, higher rpm means more air-surface friction, higher power draw and premature wear on motor and bearings, so why do this?

Gerald Loidl October 10th, 2008 01:09 AM

I did some more tests last evening and can easily reproduce this issue with every other lens and aperture setting imaginable. As soon as I use a shutter speed of 1/250th I get the issue. So it can not be dependent on the f-stop I use on the lenses or on the camera itself. Its also visible with no lens attached at all. It looks exactly like the artifacts in Bobs video.
The Ultimate is advertised to handle shutter speeds up to 1/2000th and any aperture setting.

I also looked at the rubberband and it looks pretty tight and I can not see anything wrong.

I have opened a ticket at Letus support and their first reaction was that the GG should not be visible at higher shutter speeds. I sent them a videoclip and I hope to hear back from them soon as I urgently need it for an upcoming project with high shutter speeds.

regards,
Gerald

Christopher Drews October 10th, 2008 02:51 AM

Oy! This is unfortunate.

Please keep us updated.
-C

Gerald Loidl November 10th, 2008 02:13 PM

I sent my Ultimate back to Letus to have it repaired.
It cost me more than 500.- to have it shipped back (I´m from Europe), I had to fill out tons of paperwork, take a day off from shooting and drive hours to the next airport with a customs office to send it back.

Today I got the adapter back - had to pay for the shipper and the paperwork again and drive to the airport once again to pick it up.

I reattached it to the camera and guess what? Nothing changed!! The Ultimate is still unusable with shutter speeds higher than 1/125sec. The problem looks exactly the same as before!

They did change the GG though, which had a small chip on the outside, but that did not disturb the image in any way.

I still cant believe that they sent this faulty adapter back.
Either its not faulty and higher shutterspeeds are just not possible at all - then the adapter is misrepresented in their advertising, or they sent back a faulty adapter once again and they just do not care to check it before they send it back.

I do not know...

I hope they can somehow set this issue straight - I do not want to pay another 500.- to send it back once again!
This is really a big problem for me...

regards,
Gerald

Gerald Loidl December 17th, 2008 05:26 AM

In the meantime the adapter was sent back to Letus 2 times for repairs and one time they sent me some spare parts.
It still does not work properly! To be exact - nothing changed or improved so far.

I already spent a fortune for sending it back (I´m in Europe) and forth now and I still do have a non working adapter.

They either come up with a solution for my problem within the next days or I will have no other choice but to sue them. I feel totally ripped off.

Eugene Presley December 17th, 2008 06:33 AM

You have all my symphathy. I would not hesitate myself. This is TOTALLY unacceptable!


Quote:

Originally Posted by Gerald Loidl (Post 979615)
In the meantime the adapter was sent back to Letus 2 times for repairs and one time they sent me some spare parts.
It still does not work properly! To be exact - nothing changed or improved so far.

I already spent a fortune for sending it back (I´m in Europe) and forth now and I still do have a non working adapter.

They either come up with a solution for my problem within the next days or I will have no other choice but to sue them. I feel totally ripped off.


Chris Rowe March 18th, 2010 12:21 PM

What was the result of this?
My Letus Ultimate is having a similar issue. It may be operator error, but I can't seem to get it to work with a shutter speed of 250 on my Sony EX3. It is totally unnoticeable in the EX3 view finder so you don't know there is a problem until you get back to the edit suite and see it on a full size monitor. Shots are totally unusable.

Chris


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