LetusXL Flip v2 - Dust
 

I just received my LetusXL Flip v2 today. Quyen Le had packaged it up very nicely! Unfortunately I need to get a better Nikon Lense before I can really test drive it.

I did notice some specs of dust in the unit when I held it up to the light. I emailed Quyen Le to ask him about it.

Is this something that I should be concerned about? How should I go about getting the dust out?

If the specks are not on the groundglass itself and not evident in the image on clear bright areas, I would leave it be. If on the groundglass, then it needs to be cleaned off. Do not rub, polish or use fluids for the cleaning but use a proper lens brush.

Wait for Quyen's word back on this. There are one or two tricks and treats in doing the job and he knows his own appliance best.

Thanks Bob. I'll wait to see what he says.

I got dust too.
 

I got mine yesterday..and noticed dust also...when you find out what to do then please post quyen advise when you get it.

Cary-

Congrats on getting yours... Quyen asked me to try it with video. I just some some. I'll check it out.. I'll get back to you.

Don't be too hard on Quyen over dust.

It can happen with a Mini35 also. What appears clean as the wrapping paper goes on over it may have a minute fragment or two hidden in a corner. Add violent transportation and stuff can move onto the optical path from the motion or from static electricity.

Once it is removed, you probably will not see the like of it again unless you open the appliance up another time and let something in.

The dust does not appear to casue any proplems in the video.

Bob - I just wanted to know if this was normal. Thanks for your input.

Here is some test footage.

http://blip.tv/file/179190

In an ideal world there would be no dust in any adaptor when shipped however when there is machining of plastic, dust and swarf stick fast from electrostatic attraction (not too sure about that definition). It can be hard to find and hard to budge by means such as air jets into blind areas.

I found dust on the groundlgass and in the mirror enclosure of one that I repaired. What was in the mirror enclosure did not seem to affect the image but the spot on the groundglass had to be cleaned off as it remained as a soft-edged freckle in the image after the motor was turned on.

when i got mine...mine had dust on the ground glass and it was visible even when the screen was vibrating. I remembered I had to open the thing and clean it. It was nerve wreaking to say the least. I think it would be good to have a user manual as to how to open it to clean it if needed. Has anyone documented where to open and where not to?

As you would have discovered, all that is required to get at the groundglass is to remove the thumbscrew which retains the SLR lens mount. Remove the lens mount from the front end section.

The front end section is what you want to pull out as the groundglass and motor are fixed to this. There is a small rim about 2mm thick you can get your fingernails under to start it moving.

Gently and carefully slide the front-end section forward about 15mm when the shoulder should come clear from inside of the tube. The attached groundglass carrier and motor will still be inside the tube.

At that point you need to take care to avoid the groundglass carrier catching on the side of the tube as you draw it out.

If you don't have a small vice with padded jaws to hold the body, an extra pair of hands is helpful to support the body and also the battery box from swinging on the wires and becoming damaged.

Bob-

Thanks for the explanation on "how to take apart" the LetusXL for dust removal. I must say.... I'm terrified to open this thing. I waited so long to save the money to buy it - then on delivery. I hate to take it apart and have something go wrong.

The dust does not appear to be an issue in the video. Your post is great. I hope I never have to open it up. If I do I'll be following your directions.

I think it would be great if Quyen would offer the option of caps for his adaptors. I would glady pay the extra $5 to $10 to have is shipped with caps. Don't get me wrong. My adaptor was shipped very very well. Quyen did a nice job and I'm very happy. Just a thought.

Anyone making cases for these yet?

If you want to give the nerves a good workout, try taking the back off a "mission critical" Mini35 on an actual shoot with the talent running around in the halls of an old backpacker hostel kicking up dust and ten minutes to do it in before the next take.

As for caps, it would be a nice professional finishing touch but probably not a cost beneficial value add for the customer who might be able to get them cheaper from a local source.

Unless the LETUS35 is actually taken apart, no furthur dust should get in.

There is a glass panel behind the SLR lens mount and the reversed BCX lens in front of the the flip enclosure which isolates the groundglass enclosure from the flip enclosure. The relay lens in turn seals the flip enclosure at the rear.

A very rough handheld test is here. I had access to the camera for a very short time so had to do things in haste, hence I have elevated the craft of "shaky cam" to a whole new level.

http://www.youtube.com/watch?v=-O-Dl7oZTZs

This low res clip does not show the artifacts I was attempting to provoke by using extreme shutter and aperture settings. The 1/400th sec shutter speed setting subtitled in the clip is not a typo.

Here's a look at the entrails of the modified groundglass carrier and motor/eccentric.

On the tail of the clip there is a illustration of a method of mounting the LETUS35 to 12.5mm rods by a "chair and saddle" clamping arrangement where the holes for the rods have been cut through and a single stud and wingnut used to provide the clampdown from beneath.

Also illustrated are mods to the front for imroved security of the reversable mount in Nikon orientation, an added screw to lock the Nikon lenses from turning out of the mount during focus adjustments and one of four added screws to positively retain the groundglass enclosure tube to the shoulder of the flip enclosure.

I sought to improve performance for higher shutter speeds and tighter objective lens apertures by increasing the groundglass excursion to about 1.5mm at operating speed by substituting a larger motor and heavier eccentric mass. Whilst I achieved some improvements, I also introduced more problems than I solved.

http://www.youtube.com/watch?v=SB1IN8HTM10

I might have to take this second clip down if Quyen claims copyright on the form of all his own-build components and their complete assemblage as works of art.

My use of high shutter speeds and playing with frame rates to strobe the motion of the groundglass carrier was not entirely successul and does not translate well to the framerate of YouTube.

I took the whole thing apart...no big deal..In fact you will most likely need to clean it like I did. A lot of particles that need to be addressed. And i don't want to wait another 5 weeks to get it back. As for the caps...you could just get some celphane to cover it since there is no caps for it. If not you could buy some from a local store at a nominal price.