SG Pro - Letus EX Frankenstein:

[Dennis Murphy]

Has anyone whose owned the Lex purchased the SGPro and adapted the Letus flip module to it?
I have the Lex on my XHA1 and am considering purchasing just the SGPro unit.

[Dennis Murphy]

Question #2: can users who are experienced with both adaptors tell me if they can shoot with higher shutterspeeds than 120th... if so, what can you get up to with the SGPro?

Can you stop the lens down more than say f5.6 without grain etc compared to the Lex?

Cheers.

[Dennis Murphy]

Can anyone help here?

[Bob Hart]

Dennis.


I have not used the SGPro so cannot comment with authority. I do know it is a disk system. Depending on how fast the disk spins, it potentially allows for higher shutter speeds due to the higher groundglass surface speed compared to an orbital or elliptoid movement like P+S Technik or Letus.

Iris of f5.6 is a recommended safe limit. It satisfies most conditions. Rules were meant to be broken. Some lenses will perform better than others, teles probably better than wides. Lighting conditions and the subject itself have an effect.

The artifact with orbital or elliptoid groundglass movements manifests as a twinkling or flickering in the form of a fixed pattern. The spinning groundglass artifact initially presents as a "dirtier" coloration, then depending on surface quality, arc shaped streaking may appear with the artifact becoming more evident towards disk centre where the surface speed is slower.

The vendor or Phil Bloom should be able to advise you better on this subject.

[Leonard Levy]

I guess you would have to open your Letus Extreme to see if the flip could be used separately - Hmm interesting idea that I've never tried.

i doubt if its that easy as Wayne tried to market the a Letus flip with the SGPro last January, but it didn't seem to be so simple. They never did end up collaborating after an intial start. That implies that more work needed to be done to amke them work togetehr, but I'm just guessing.

Lenny Levy

[Dennis Murphy]

Thanks for the replies.
I assume that the spinner would allow for higher shutter speeds than the Letus. I own the Letus, but hate the idea of flipping in post etc.

[Bob Hart]

I won't say you can't do it but I suggest that it might not be a sweet and trouble-free connubiality.

The front of the Extreme's flip enclosure now also is the base for the groundglass carrier pillars which now swing from the rear, not the front as with the original Letus35.

There may be unique aspects to each design relating to optics as both products have matured beyond backyard workshop innovation.

I imagine you would need to redesign the front plate for the Letus flip enclosure. It may be that the path from rear of flip enclosure to the groundglass is longer than the achromat for the SGPRO is intended to allow for and you would have to replace this with a less powerful one.

Then there is the issue of the condenser. If the SGPRO has one and I imagine it will have, then this may be tailored for the existing SGPRO achromat and might also need to be replaced with one which matches the less powerful achrmomat.

It might be a simple case of using all the optical pieces of the Letus Extreme and hacking the SGPRO minus its achromat and condensor onto the front. Some sophisticated design, machine workshop skills, machinery and metal stock would be needed to make up the bridging work and get it centred.

By the time you muster those resources together or sub the task out to someone with those resources, you might end up just as broke as you would be if you went for the Letus Ultimate.

Before dismissing the SGPRO flip, why not email Wayne Kinney and get the word directly from the man himself.

[Dennis Murphy]

Thanks for the replies Bob... very informative as per usual.

I usually shoot wide open with my lenses 99% of the time, so smaller than 5.6 isn't an issue for me.
I was just wondering if the spinner allowed people to go 250th - 500th second with their shutter, as this is not an option with the Letus.
I'm pretty handy in the workshop, so am confident around mating the Letus flip module to an SG Pro spinner. I was concerned about the optical issues that you've clearly highlighted.

Being the poor videographer that I am, I was trying to avoid spending money on the SG Pro flip module.

If people with the SG Pro are able to shoot at 500th second without it capturing the disk, I'd like to know.

[Bob Hart]

Dennis.


You may have seen this already. Here's a clip of where it goes when you push the shutter speed up with a 120mm diameter disk. You will observe some artifacts. Wayne's disks are better quality than mine but may be a smaller diameter. He can advise you on the tech stuff.

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

[Dennis Murphy]

That's impressive!
I imagine at 1/500th it would be sweet apart from existing blemishes on the glass that would show at around 1/100th anyway?

I don't even bother going beyond 1/75th with the Letus.

[Bob Hart]

The Extreme will tolerate 1/100th sec on an EX1. It might be a different story in overbright high contrast conditions however on this slow-mo test in overcast and intermittently rainy conditions, it was fine.


This one has also been posted previously so it might be boring for others by now.


CONGORO - SLOWMOTION TEST. OVERCAST AND RAIN CONDITIONS By Bob Hart On ExposureRoom

[Dennis Murphy]

Nice stuff Bob!
I've done 1/120th with the Extreme, but I don't like to go above 1/75th.
If only I could afford the Ultimate... boohoo poor me.

[Jeremy Hughes]

Jump on the shoot35 site and look in the forums there. I was going to get an SGPro a while back but had to put it on hold. I had emailed Wayne and done a lot of research. You can def go well above 100th on the shutter speed but not sure how high. You of course can stop down like crazy too. And Waynes stuff has a great bokeh. BTW, I thought he was already shipping with a flip - thats what I almost bought a couple months back.

[Igor Babic]

I have seen both systems LEX and SGpro in same week and I also think that Bob is wright.

You must have a lot of luck and some machining skills or machine service that can join those two together. Sgpro has large condenser lens that is mounted very near gg disk. Condenser is mounted on casing in very similar way like achromat on LEX flip. LEX condenser is little further away from gg and round extension that is actualy holder for vibra mechanism, condenser and slr mount tube is much thicker than sgpros flip on this place, so your lex flip will be around 2 cm and some further away from spin gg and you have to make some adapter ring to connect them both. I think that you can't connect them together directly because Lex has closed front (only opening for condenser and sg pro flip is like ring in front) Sg pro flip has round ring in front of his flip that goes in sgpro ring instead of achromat and allow enough place to avoid contacting sg pro condenser lens. (see tutorial on sgpro site on how to install flip and you will see what I am talking about.)

We have try to connect sgpro flip to Brevis, but sharpness was found only at infinity ( and I dont know if is sharp enough) because gg was to far away in Brevis. We didnt experiment too much after that to see vigneting, edge sharpness etc...

I think that renting a LEX or selling it is better idea and switch to sgpro+flip if it goes over 1/100. Sgpro has anounced that they will stop further production of sgpro and switch to blade, and you have to try and decide quick...

[Chris Barcellos]

Just to add a twist here, I have shot the Letus FE, not mine, which is the forerunner of the Extreme, except with mirror flip instead of prism. On an occasion to do a field repair (intermitent vibration) I opened up the front end. It was pretty much a shorter (tube length) version of my old Letus35a.

So one day, I decided I want my own flip capability. I looked at EX, and I looked at Letus Fliip module. I ended up ording it, for $600.00. I ordered the Brevis version (assuming that had to do with threading issues) as they didn't have a version to add to their own 35a.... When it arrived, I saw that the flip unit had it own achromat. I popped the one out of the original 35a, and even pulled the condenser out, as FE had no condenser on board.

Sure enough, the marriage worked fine, and I am not having any major issues with vignetting, that I thought I might see without the consenser.

While I haven't actually tried to marry it to my DIY spinning adapters yet, I have no doubt that will work too....