hi everyone! i'm going to a studio session this evening for a band that i will be shooting a music video for and would like to get some b roll images to splice in to the video. i will be using 2 sony vx2100s and a vx2000, each equipped with a letus35 and the following lenses: 50, 28mm, 28-105mm. the problem is, there are bits of dust (probably bits from the housing, leftover from machining and made loose from use) that are stuck between the achromat and the macro. i do not know how to get between them to clean it up as it looks like it's glued together. anyone have this issue? how can i clean the glass?

thanks in advance!

A.J. Briones

Do you mean it's between the 2 glass that cemented together? If it's between the achromat and condenser, remove the screws then take the whole part out then clean in there. Sometimes it's a little tight, use flat head screwdriver to take it out the way you open the paint can, thanks.

Quyen

A.J. Briones

Do you mean it's between the 2 glass that cemented together? If it's between the achromat and condenser, remove the screws then take the whole part out then clean in there. Sometimes it's a little tight, use flat head screwdriver to take it out the way you open the paint can, thanks.

Quyen

hi quyen! it's between the 2 glass that are cemented together. is there a way to clean between that area? this is the case with all 3 of my adapters.

i'm afraid that i will break them if i try to clean them myself, and i'd rather spend hours and hours pixelshifting the dust out in post rather than shooting without it this evening.

Are they on the glass that next to camera lens? It's weird that all 3 has dust inside. The cemented, I don't know how to clean inside. Does it show on video? The dust cannot get inside the cemented achromat since it was cemented from the factory, and if there is anything on that achromat, it won't show up on video because it's way out of the focus range. Thanks.

Quyen

Are they on the glass that next to camera lens? It's weird that all 3 has dust inside. The cemented, I don't know how to clean inside. Does it show on video? The dust cannot get inside the cemented achromat since it was cemented from the factory, and if there is anything on that achromat, it won't show up on video because it's way out of the focus range. Thanks.

Quyen
hi quyen. please refer to the following clip:

http://www.infinite-studios.com/movies/letusclip.mov

there is one piece of dirt, two thirds horizontally, on the bottom 4th of the screen. it is one single spec. it is behind the outermost glass that faces the camcorder. this is with just one of the adapters. the other 2 are connected to the cameras and i will update you on their condition soon. i will take each one apart to clean them and will report later.

if you have any other advice that can help me with cleaning them, i very much appreciate it.

cannot download, missing something in the link?

Quyen

Previous link does not work for some reason: http://dandiaconu.com/gallery/albums/album06/underwater.wmv

I tried to watch it several times but cannot locate the dust, is it because of compression? can you grab 1 frame at full resolution? thanks.

Quyen

oh man... wait... my bad... i accidentally pasted one of dan's clips instead of one of mine.

post has been edited. clip is here:

http://www.infinite-studios.com/movies/letusclip.mov

sorry for the confusion dan and quyen!

Are you sure that was the one on the Achromat, not condenser? Any dust on the camera side of the condenser barely shows and the achromat is much further away. Can you double check to see if it's not on the condenser? thanks.

Quyen

Are you sure that was the one on the Achromat, not condenser? Any dust on the camera side of the condenser barely shows and the achromat is much further away. Can you double check to see if it's not on the condenser? thanks.

Quyen

will do. i'm going to take these apart later this afternoon. we are going to have a 3 camera shoot tonight and i hope to have some footage shortly afterwards. i'm really hoping this can be fixed. if my digital camera wasn't broken i'd take stills too.

I'm having the same problem with my adapter. I've gotten the specks using a DVX, a Sony Digital8, and my newly purchased GS-400 (Which I must say works great with the Letus35). All of them in the same place every time.

I have cleaned the adapter meticulously but it is still there in the same exact spots. The adapter is great, except for the 4 specks that I am seeing.

I believe it is in between the focusing screen and the small rectangular achromat (or is that the condensor) that is glued to the inside of the adapter. I've cleaned that part off, well at least the part I can get to.

Either that or it is a blemish on the focusing screen itself.

Here are a couple grabs:

http://www.tonytibbetts.com/DustSpeck01.jpg
http://www.tonytibbetts.com/DustSpeck02.jpg

A.J.,

Let me know how it goes, I'd like to be able to clean those specks off if I can.

If it's between the condenser and GG, take the whole front part off then clean them off. If it's on GG, use cotton rich cloth to dust it off, thanks.

Quyen

ok. i just came back from the shoot. there's footage rendering now, and i will share some screencaps soon. here's what i can tell so far:

there are 2 (maybe 3) pieces of dirt between the two cemented pieces of glass that i cannot get to. most of the time, it is not seen in the shot. however, at times, it will show up, and will look pretty horrible when it does.

i like really soft shots and sometimes i shoot in a way where nothing is in focus. the problem is, sometimes i trigger the dv camera's auto focus, and when this happens, the specs of dirt come into view. this also happens sometimes when i rack from one end of the focal spectrum to the other. i cannot set the camera to manual focus because of the fear that i may inadvertently touch the focus ring and ruin my shot.

question is: how do i get this dirt out of the lens? i have a major shoot on the 29th, then the music video shoot is for real on the 2nd and 6th, and i will need to resolve this issue soon. any ideas?

Send it back and I will replace it for you, thanks.

Quyen

It seems like most Letus35 buyers have had this issue with dirt. You have it in all 3 units you bought. That should clearly point there's a QC problem there. Can't it be troubleshooted and solved? I may be buying one in the near future, but this dirt problem is not a really big turn on. It's not really a nice thing to have to open a brand new unit to clean when you get it. I hope it gets solved.

Okay...I completely forgot that you can take off the front part of the adapter..D'oh!!!

After doing that I wiped off both the surface of the focusing screen and the condenser. Used some compressed air on both and put the adapter back together.

Results? Good and bad.

Good: At first glance some of the specks have disappeared.

Bad: It appears some have just moved elsewhere.

Is there a cleaning solution I can use on the cloth while cleaning off the focusing screen?

Michael,

Yes there are few minor specks of dirt that can be cleaned off, it doesn't make it a bad adapter. You can still get dirt in an M2. Quyen is always helpful when it comes to solving any problems one might have with the adapter. For the price you can't beat it. IMHO I prefer this adapter over the M2. I'll take a few specks of dirt I can clean off over the M2's ghosting issues any day.

Not bashing it really. But this issue is being going on for a little while now. You would think it could have been tracked and solved. But I AM impressed by the latest clips with the Letus35.

Tony Tibbetts

Use dry Q-tip to clean the smooth side, use water to clean the other side and dry it with cotton rich T-shirt. Thanks.

Quyen

Thanks Quyen,

I'll give that a shot.

*update:

Okay, after doing what Quyen said, I was able to remove most of the specks.

Then I took a bit of a risk and used a small amount of windex on the focusing screen.(yes I know you shouldn't use chemicals). but the results turned out quite good. I was only able to spot one small speck in the center of the screen which wasn't nearly as dark as the spots before it. So I think with one more cleaning, the specks will be gone.

i still have not had time for a cleaning, but it appears that in low light conditions the specks are not as visible. for some reason, they really show up in outdoor shots.

here is some rehearsal test shots for a music video that we plan to shoot for real (with better lighting, multiple locations, audio source to sync to and a few cg shots!) on the 2nd and 6th of november:

http://www.infinite-studios.com/movies/Emily_test.mov

the speck shows up in some places, an example is at 0:13 (to the left of the microphone just over the lead singer's shoulder).

you can also see the unedited, unfiltered clip here:

http://www.infinite-studios.com/movies/Emily_test_RAW.mov

upon examination, you will see a few specks come in and out of focus.

i'm going to try to take these apart and clean them thoroughly. if i am still getting these issues, i will take you up on your generous offer, quyen. thanks again for the amazing customer support!

What camera? I kind of like better the unfiltered version.

What camera? I kind of like better the unfiltered version.
this was shot with a vx2100. the unfiltered shot looks great, but blown up to full screen on my nle, it was grainy due to lack of light. the filtered version tells us that we need to use a 1k and a fill when it comes time to shoot for real at this location.

I wrote a small cleaning how-to and gave it to Quyen, don't know if it is up on his site yet, you might check there for info.

The plastic pieces are a product of the Plastic Moulding that Quyen is making. Nothing major, just compressed air to get rid of it.

Tragedy strikes...sorta

Cleaning the focusing screen, contrary to what Mandy says, is not as easy as using compressesed air.

Quyen's method works for the most part. As I stated in my previous post I felt it need another once over, as there was still one speck left. Well my tenacity and sausage fingers got the better of me, I accidentally popped out the focusing screen glass. Not a big deal, but when I tried to put it back in it got chipped and cracked.

Oops...well I was flustered for a few hours and then I remembered a how-to 35mm adapter intsructional that was online. Wherein the person used the frosted dummy CD that comes in some CD spindles as the focusing screen.

Ah HAH!!! After tearing my house apart (I knew I had one somewhere) I found it. Cut it to fit in the space where the original focusing screen went and voila!!!

To my surprise it works exceptionally well. To my eye I can't tell the difference on my 46 inch widescreen Sony TV

Nice and easy way to fix the adapter if something happens to the focusing screen.

Ironically I just opened up my Letus35 because there was (you guessed it) dirt on the ground glass. As I was in there, the ground glass popped out of the frame. When I was trying to put it back in it cracked into two pieces.

Sigh....


So I had to take my Nikon D screen and glue it in where the ground glass once was. I get amazingly good results, and because of the Nikon D's built-in lens I no longer have a need for the PCXL lens that was in there, which takes down the heft a bit and the complications should I drop the unit. However, it's--you guessed it--dirty, so I have to go back in there again. The D screen is a good bit heavier than the GG that was in there is, so the vibration motor is going to need a power boost.

Yuck.

that's funny, because that's exactly what happened to me the very first time i opened it up to clean it. i put it back with the chipped part that was, thankfully, on the outer perimeter of the gg and out of the field of view.

question: are these just held in via friction or should they be glued on?

On the recent units, I glued them on. You can put glue on if you want it to hold on tight. If anybody need replacement for GGs, please let me know, thanks.

Quyen

I'm suprised I didn't break my GG. It fell out when I was cleaning the unit and I could not figure out how to get it to sit back in it's hole. I was pushing on it pretty hard for awhile until i noticed a tiny slit on the backside of the hole it sits in.

Also, a WARNING to everyone who is taking their adapters apart, DO NOT remove the white plastic legs from the little rubber boots that hold them in place. I thought it would fun to take everything apart, but it took me about 30mins to force one of them back in. I had alot of blisters and almost destroyed the rubber piece but I got it back in there.

I echo that statement. I actually broke one of the legs--thank goodness for hot glue.

Wow...and I thought I was being rough on mine. Using a D screen is an interesting idea.

The D screen is a good bit heavier than the GG that was in there is, so the vibration motor is going to need a power boost.

Ben,

I modified my Letus35 to accept different battery packs. Here are some pics:

http://www.tonytibbetts.com/letusmod01.jpg
http://www.tonytibbetts.com/letusmod02.jpg

Not the greatest pics, but you get the idea.

Just to warn you though, the 6V battery pack can get pretty noisy.

On a side note: For anybody who's interested, on the frosted CD the grain is so uniform that you can almost shoot without the vibration...well almost. I have to use the shadows to get the video cameras macro to focus on the screen.

Ironically Tony I did the exact same thing, with the kind of three-pin connectors they use with computer fans.

looks like i'm going to be taking a trip to radio shack soon. thanks for sharing, guys!

question: does the stronger vibration from the 9volt affect the stability of the camera?

Probably not. The size of the motor limits the thing to only so much vibration, and I seriously doubt something as small as a dime can really affect the camera.

Ben,

I was wondering how well the Nikon D screen would work with the Letus35, do you have any side by sides of the old GG and the Nikon Screen? How is it in Low light situations?

I think the 9V players out there are a good idea - we need some side X side of those as well to see how they stack up!

9v is too much for the motor, thanks.

Quyen

mandy,

My Nikon D Screen has a large blemish in it that polished out the ground glass, so now I have a portion of my D screen that shows the aerial image. The screen is essentially ruined. I can take a few test shots with it but it will have that imperfection. I can then shoot the same shot with Quyen's ground glass in place once the replacement comes in the mail. But from what I have seen with the Nikon D screen in place, there does seem to be less grain, if not better light transmittance. It's hard to beat Quyen's ground glass in terms of that.

Also guys, for those of you who want lens covers for each side of the Letus35, try the smaller side of lens filter cases overtop each side held on by a rubber band around the whole thing lengthwise.

9v is too much for the motor, thanks.

I agree, I wouldn't run it past 6V. Trust me, it's way noisy at 6V. I would recommend against it.

Although I have been debating setting up a 6V battery pack with a fader type knob to alternate the speeds of the motor. That may be something someone here would like to experiment with.

I wrote a small cleaning how-to and gave it to Quyen, don't know if it is up on his site yet, you might check there for info.

The plastic pieces are a product of the Plastic Moulding that Quyen is making. Nothing major, just compressed air to get rid of it.

hi mandy, this how-to is not up on the site yet. is it possible for you to email to me? i can also host it, if others would like to see it.

thanks!

Although I have been debating setting up a 6V battery pack with a fader type knob to alternate the speeds of the motor. That may be something someone here would like to experiment with.

Tony: That actually wouldn't be too difficult. All that's needed would be the variable resistor (aka potentiometer) between the motor and the power source. These can be had from Radio Shack for a couple of bucks.

I really can't post it without Quyen's permission, so he will have to give you the go ahead, sorry!

Leo,

It's your guide, I don't see any reason you can't post it. There are some differences on the Letus35 version (I am not saying 35A I just upgrade it a little by little without posting). So the guide for your unit doesn't cover all other units but the basics are really similar, thanks for putting the guide together. I just don't have time to make it universal, thanks.

Quyen

Tony: That actually wouldn't be too difficult. All that's needed would be the variable resistor (aka potentiometer) between the motor and the power source. These can be had from Radio Shack for a couple of bucks.

Yes, I know. I'm lazy. I was merely hoping someone else would dop it and tell me how well it works.

I got some blurred spots on my GG on the Letus35, some spots that looks softier than the whole stuff. it is some kind of dirty? how do i clean the GG?

thanks!

This is a long shot, pertains to operating practices and probably invalid but here it is to waste some server space anyway.

Autofocus with the videocamera works for quickly setting up the relay focus but is not always foolproof. Manual focus is preferred. Whe you set up a lot of soft area in your shot, the videocamera is going to chase that which appears sharpest to it, in this case anything in the image path which can be made to be sharply defined, in this case possibly specks which otherwise might not be apparent.

I suspect you may find that when these blemishes are most apparent, overall sharpness may have also gone off, meaning the videcamera focus has moved off the groundglass. When you reset the SLR (front lens) focus to sharp, the videocamera may well go back to whatever can be made to appear sharpest, which may be the groundglass image. Or you may have manually reset the videocamera relay focus yourself before switching back to auto.

With my arrangement, the PD150 and a 2 x 90degree prism path, the path is very prone to getting bits of grit and dust because of my own untidy construction methods with the prototype. If I leave the videocamera on autofocus after initial setup, as soon as I play with focus pulls to create soft focus transitions, the videocamera focus wll crash to the closest sharply definable mark. Sometimes this is a bit of dust on the front glass of the videocamera itself. Focus will stay there and I manually over-ride it.

Whilst specks in the image path are not good and may emerge as out-of-focus dark areas in certain lighting conditions, locking off your manual focus might be a best practice to minimise the defect. I would favour taping over the focus and zoom rings ring so they cannot be disturbed.


My own personally favoured operating practices :-

After relay focus setup, mask over the focus and zoom ring controls to prevent accidental adjustment.

Set video gain to 0db.

Attempt to maintain videocamera aperture setting at no smaller than f5.6. ( if this is a selectable option.) - helps keep specks soft and the autofocus out of temptation's way. This setting also limits diffraction issues relating to small-CCD video cameras.

Use in-camera ND filter selections to keep to this aperture setting or add pieces of neutral density filter gel between the SLR lens and groundglass to bring light levels within a manageable range.)

1/50th sec shutter speed is preferred.

Try to avoid high light levels being predominent in your out-of-focus backgrounds. Any blemishes in the path which coincide with the soft bright out-of-focus zones will be more apparent in these shots.

(The higher contrast caused may also aggravate the tendency for autofocus to chase specks if autofocus really must be remain selected on. - This is a real problem for me when I use the device without the groundglass to aquire via aerial image through really long lenses. I don't use the groundglass with these lenses because they are most often of an aperture smaller than f5.6 which causes the groundglass texture to become apparent.

I use the autofocus to track objects moving towards and away from my viewpoint. Aircraft against a strong bright background sky wll normally hold via autofocus but if the subject momentarily exits the frame or an insect flies through, this is enough to set off an autofocus crash to the closest sharp object, the speck in the relay path.).

Ignore at will as I am no expert. The handling notes for the P+S Technik devices are valid for the alternative devices.