Letus35 FE flare or something at DVinfo.net

Sean Michael · January 28th, 2007, 06:09 PM

With my Letus35 FE, I get this small looking horizontal flare just below the middle of the screen... It comes and goes as it pleases, more apparent with using lights. I get it using all of my nikon lenses. Anyone else have this problem? or could help?

Sean Michael · January 28th, 2007, 06:22 PM

It's almost like a ghosting effect

Bob Hart · January 29th, 2007, 09:28 AM

This issue is an uncommon one, an exception even.

It might be a light leak but more likely a reflection artifact between the SLR camera lens and the front face of the groundglass.

Quyen seems to have taken care to seal the junction between the two halves of the flip enclosure with a tape material of some kind to prevent the possibility of light leaks, fluid and dust ingress, yet retain ability to dismantle the enclosure if needed.

Have you removed this tape, opened the case, gone for a look inside and not replaced the tape??

A reflection artifact has been observed with some home-made adaptors including my own but it seems to be fairly rarely an observable problem more than a minor pinpoint.

Can you provide some more info so the collective brains trust have something more to bite on.

In particular :-

Camcorder type and model.
Shooting conditions.
SLR lens type - Nikon or Canon?
SLR lens aperture when artifact occurred.
Is the SLR lens mount dead square in the front housing of the Letus35.

Post a .jpg frame grab if you can.

If the flare artifact is of a vertical letter "V", "U", or letter "CX" shape laying on its side with the ends facing up like the letter "U" with the "X" on top, then the SLR lens may be simply drooping down at the front and some internal reflection going on.

In this event, the artifact may likely only turn up when you are shooting against a pinpoint light source or a broader strong source hidden behind broken cover like a leafy tree canopy. It may go away if you support the front of the lens.

My comments here may also be the beginnings of a goose chase so don't pay too much heed.

Enquire with Quyen. It may be a new issue which he might need to know about if he has revised the design recently or it might be something easily fixed.

Ram Shani · January 30th, 2007, 04:56 AM

do you work with uv filter on the slr lens

i had the same problem and it was from the uv

Christopher Witz · February 17th, 2007, 10:03 AM

I had the same issues with my flip.... ended up being the side walls inside the flip needed to be made black and non reflective.... I took it apart and painted everything that was not optical with flat black model paint.... the painted the parts of the opticals that were out of image view flat black as well....

the results removed the flare/internal reflections and increase the contrast of the image.

Bob Hart · February 17th, 2007, 12:40 PM

Christopher.

Very interesting. Did you by any chance find a point anywhere in the path where this internal reflection becomes almost sharply focused. There's a fixed pattern artifact being experienced by a few operators with HD cameras.

If you have time, pan your camera/Letus past a bright plain wall or side of a large light coloured motor vehicle with the taking lens aperture at f4.

If your black paint eliminates it, the screwdriver and paintbrush is coming out over here.

Christopher Witz · February 17th, 2007, 03:49 PM

yes.... I 1st noticed it with a pained window ....

The additional painting I did helped allot... but I think if the optical components are "coated", the the reflections would completely disappear.

I don't have the letus anymore.... so I can't do anymore tests.... sorry

January 28th, 2007, 06:09 PM	#1
Sean Michael Regular Crew Join Date: Dec 2003 Location: Phoenix, Arizona Posts: 49	Letus35 FE flare or something With my Letus35 FE, I get this small looking horizontal flare just below the middle of the screen... It comes and goes as it pleases, more apparent with using lights. I get it using all of my nikon lenses. Anyone else have this problem? or could help?

January 28th, 2007, 06:22 PM	#2
Sean Michael Regular Crew Join Date: Dec 2003 Location: Phoenix, Arizona Posts: 49	It's almost like a ghosting effect

January 29th, 2007, 09:28 AM	#3
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,476	This issue is an uncommon one, an exception even. It might be a light leak but more likely a reflection artifact between the SLR camera lens and the front face of the groundglass. Quyen seems to have taken care to seal the junction between the two halves of the flip enclosure with a tape material of some kind to prevent the possibility of light leaks, fluid and dust ingress, yet retain ability to dismantle the enclosure if needed. Have you removed this tape, opened the case, gone for a look inside and not replaced the tape?? A reflection artifact has been observed with some home-made adaptors including my own but it seems to be fairly rarely an observable problem more than a minor pinpoint. Can you provide some more info so the collective brains trust have something more to bite on. In particular :- Camcorder type and model. Shooting conditions. SLR lens type - Nikon or Canon? SLR lens aperture when artifact occurred. Is the SLR lens mount dead square in the front housing of the Letus35. Post a .jpg frame grab if you can. If the flare artifact is of a vertical letter "V", "U", or letter "CX" shape laying on its side with the ends facing up like the letter "U" with the "X" on top, then the SLR lens may be simply drooping down at the front and some internal reflection going on. In this event, the artifact may likely only turn up when you are shooting against a pinpoint light source or a broader strong source hidden behind broken cover like a leafy tree canopy. It may go away if you support the front of the lens. My comments here may also be the beginnings of a goose chase so don't pay too much heed. Enquire with Quyen. It may be a new issue which he might need to know about if he has revised the design recently or it might be something easily fixed.

January 30th, 2007, 04:56 AM	#4
Ram Shani Regular Crew Join Date: Dec 2006 Location: tel aviv israel Posts: 107	do you work with uv filter on the slr lens i had the same problem and it was from the uv

February 17th, 2007, 10:03 AM	#5
Christopher Witz Major Player Join Date: Feb 2006 Location: Louisville, KY Posts: 591	I had the same issues with my flip.... ended up being the side walls inside the flip needed to be made black and non reflective.... I took it apart and painted everything that was not optical with flat black model paint.... the painted the parts of the opticals that were out of image view flat black as well.... the results removed the flare/internal reflections and increase the contrast of the image.

February 17th, 2007, 12:40 PM	#6
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,476	Christopher. Very interesting. Did you by any chance find a point anywhere in the path where this internal reflection becomes almost sharply focused. There's a fixed pattern artifact being experienced by a few operators with HD cameras. If you have time, pan your camera/Letus past a bright plain wall or side of a large light coloured motor vehicle with the taking lens aperture at f4. If your black paint eliminates it, the screwdriver and paintbrush is coming out over here.

February 17th, 2007, 03:49 PM	#7
Christopher Witz Major Player Join Date: Feb 2006 Location: Louisville, KY Posts: 591	yes.... I 1st noticed it with a pained window .... The additional painting I did helped allot... but I think if the optical components are "coated", the the reflections would completely disappear. I don't have the letus anymore.... so I can't do anymore tests.... sorry