I can't detach the Nikon lens!!! help!

Giovanni Speranza · April 6th, 2007, 12:06 PM

Respect.

C'mon Bob, you are an authority about everything and Letus!

Now i have the typical Letus question. I have 3 black dust points on the mirrors or a lens. What is the easier, less destructive way to reach them and clean it?
I have to film next week and with that dust i'm ko.
Thanks for your precious help.
Joe
PS: the dust is not on the ground glass because it remains there when i turn the Letus on.

Bob Hart · April 7th, 2007, 09:17 AM

Joe.

Check motor is working. Dust spots on groundglass do not go away when the motor is on. Dust spots become blur in video image when the motor is on.

Have a look at the clip linked at the bottom of this post. I made a mistake and posted the link on another thread. I should have posted it here.

Do not pull the flip enclosure (mirror box) to pieces. It is all parts glued and one mirror pair has to break the glue for it to come apart. Too hard to put back together again.

There can be lots of dust in it but you should not see spots sharply on the mirrors with the videcamera.

System for looking for dust.

Take lens off front of Letus. Look through videocamera. Is the spot still there?

Take front off Letus35. This will take out groundglass, motor and
battery pack. Look through videocamera. Is the spot still there? Adjust videocamera focus. Does the spot go soft or stay sharp?

Shine a torch light in the front of the mirror box. Is there a spot on the condenser?

Remove condensor. Look through videocamera. Is the spot still there?

Take Letus35fe off front of videocamera. Look through videocamera. Has the spot gone.

Shine torch in front of mirror box. Look at torchlight through macro lens on back of Letus35. Can you see a spot on the lens?

When you have taken the macro off back of flip enclosure (mirror box) and condenser out of front of flip enclosure, to get dust out of the flip enclosure (mirror box), switch on a big CRT television. not LCD.

Use compressed air or camera canned air. Hold the flip enclosure very close to the TV screen but leave a little space for air to come out one end of the flip enclosure.

Shoot air jet in through the hole in the other end. Dust may keep moving right trough and stick to the TV screen.

Nearly always, any spots you can see with the videocamera will be on the GG or maybe on the condensor lens on front of the flip enclosure (mirror box). If the spots are anywhere else, you will not see them.

Do not pull your Letus to pieces unless you really have to do this.

This is about as much help I can give. The Letus35 I have is a direct relay model and from the flip enclosure to videocamera, it is different to yours.

http://www.youtube.com/watch?v=yugfv4ZVXgg

Giovanni Speranza · April 7th, 2007, 09:10 PM

I tried your TV post trick and it worked!!! no more dust!
Thank you very much Bob!

Brandon Paschal · July 14th, 2007, 07:29 AM

Quote:

Originally Posted by Bob Hart

Sorry I used too much words.

Unscrew the thumbscrew until mount can pull out to front.

Remove mount from Letus35.

Look inside the Letus mount from back end.

Get wooden satay stick or toothpick. Use it to put drops of oil on jammed mount where back of lens touches it.

Twist lens clockwise only until it begins to move.

Twist back a little.

Twist clockwise again.

Move it in small twists until it loosens. Then try to force it again.

(Langsam arbeit???? - Please forgive. Ich habe sehr kleine deutsch von schuljunge tagen und "Inspector Rex" und neine Franzosisch.).

Might this philosophy also pertain to Brevis owners? I understand this is the Letus forum, but I am experiencing the same issue with my 50mm Nikon lens attaching to my Brevis. Once I hear the "click" (this has only happened twice - although I've only had it for one day), it's very difficult to detach. I imagine it is because the camera detach button is not available.

--Brandon

Dennis Wood · July 15th, 2007, 12:10 AM

Brandon, just depress the lens release button (back towards the Brevis unit) and twist to release. If the button is hard to press back, just twist the lens slightly (try both directions) as it's likely loading up the release pin.

Brandon Paschal · July 16th, 2007, 06:14 PM

Dennis, thanks for the heads up. I'll get there - I promise. This weekend's shoot (the first day of tests) went phenomenally. I am having a bit of an issue using the rail system, but nonetheless, the images are amazing.

I can't wait to get the flip module and/or field monitor. This venture is expensive, but the cost of great images!

Thanks,

--Brandon

April 7th, 2007, 09:17 AM	#17
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,476	Joe. Check motor is working. Dust spots on groundglass do not go away when the motor is on. Dust spots become blur in video image when the motor is on. Have a look at the clip linked at the bottom of this post. I made a mistake and posted the link on another thread. I should have posted it here. Do not pull the flip enclosure (mirror box) to pieces. It is all parts glued and one mirror pair has to break the glue for it to come apart. Too hard to put back together again. There can be lots of dust in it but you should not see spots sharply on the mirrors with the videcamera. System for looking for dust. Take lens off front of Letus. Look through videocamera. Is the spot still there? Take front off Letus35. This will take out groundglass, motor and battery pack. Look through videocamera. Is the spot still there? Adjust videocamera focus. Does the spot go soft or stay sharp? Shine a torch light in the front of the mirror box. Is there a spot on the condenser? Remove condensor. Look through videocamera. Is the spot still there? Take Letus35fe off front of videocamera. Look through videocamera. Has the spot gone. Shine torch in front of mirror box. Look at torchlight through macro lens on back of Letus35. Can you see a spot on the lens? When you have taken the macro off back of flip enclosure (mirror box) and condenser out of front of flip enclosure, to get dust out of the flip enclosure (mirror box), switch on a big CRT television. not LCD. Use compressed air or camera canned air. Hold the flip enclosure very close to the TV screen but leave a little space for air to come out one end of the flip enclosure. Shoot air jet in through the hole in the other end. Dust may keep moving right trough and stick to the TV screen. Nearly always, any spots you can see with the videocamera will be on the GG or maybe on the condensor lens on front of the flip enclosure (mirror box). If the spots are anywhere else, you will not see them. Do not pull your Letus to pieces unless you really have to do this. This is about as much help I can give. The Letus35 I have is a direct relay model and from the flip enclosure to videocamera, it is different to yours. http://www.youtube.com/watch?v=yugfv4ZVXgg Last edited by Bob Hart; April 7th, 2007 at 09:32 AM. Reason: errors

July 16th, 2007, 06:14 PM	#21
Brandon Paschal Regular Crew Join Date: Mar 2007 Location: United Kingdom Posts: 77	Much appreciated ... Dennis, thanks for the heads up. I'll get there - I promise. This weekend's shoot (the first day of tests) went phenomenally. I am having a bit of an issue using the rail system, but nonetheless, the images are amazing. I can't wait to get the flip module and/or field monitor. This venture is expensive, but the cost of great images! Thanks, --Brandon __________________ p-films.com. Canon T2i f2.8 17-55, f1.4 50mm, Cool Lights LEDs

April 6th, 2007, 12:06 PM	#16
Giovanni Speranza Regular Crew Join Date: Aug 2006 Location: Lugano, Switzerland Posts: 149	Respect. C'mon Bob, you are an authority about everything and Letus! Now i have the typical Letus question. I have 3 black dust points on the mirrors or a lens. What is the easier, less destructive way to reach them and clean it? I have to film next week and with that dust i'm ko. Thanks for your precious help. Joe PS: the dust is not on the ground glass because it remains there when i turn the Letus on.

April 7th, 2007, 09:10 PM	#18
Giovanni Speranza Regular Crew Join Date: Aug 2006 Location: Lugano, Switzerland Posts: 149	I tried your TV post trick and it worked!!! no more dust! Thank you very much Bob!

July 15th, 2007, 12:10 AM	#20
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Brandon, just depress the lens release button (back towards the Brevis unit) and twist to release. If the button is hard to press back, just twist the lens slightly (try both directions) as it's likely loading up the release pin.