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Subject: Important test for TL-120 (Chinese Camera) Users
Date: 2006-11-05 23:57:39
From: Sam Smith
Hi All,

It has been brought to my attention that a prior problem with the
eyepiece of the Chinese TL-120 stereo camera MAY have not been
corrected. It appears the current stock may be using an eyepiece with
too short a focal length, rendering the screen out of focus.

I would like to take a poll to confirm this. Please have a look at the
two images in the PHOTOS section of this newsgroup. It shows a simple
method of finding out if your camera has the same problem.

Please try the following:

1. Remove the prism from the camera, turn it upside down so the flat
side is on top
2. Place a piece of ground glass over the top. If you don't have
ground glass, just run a strip of transluscent Magic Tape tighly
across the metal frame. I used a piece of thin transluscent plastic in
the picture.
3. Point the eyepiece it out a window, making it a camera obscura. If
a distant object at infinity is in sharp focus on the groundglass, you
have a problem. If it is blurry and NOTHING is in focus, you should be
OK. If something in the foreground is in focus, you really have a problem.

I would appreciate it if current owners can respond to this, as I need
to know what exactly is being currently shipped.

Thanks,

Sam
Subject: test for TL-120 (Chinese Camera) Users+ comments
Date: 2006-11-06 18:54:46
From: Dale Yingst
Mine just arrived today. Somehow between looking at it at NSA
and receiving it, it seems to have gotten bigger and heavier
:-) The prism lock is not so great as mine has slid off twice
already just from the general handling of the camera. My big
concern is that my lenses are not matched in the apertures.
They are about 1 fstop off. THere is a gear linking the
lenses, but I won't touch it until someone can tell me if that
is the way. Hopefully it will be easy.

I haven't done the test Sam asked yet, but don't remember
this being a concern in his initial impressions. I can say
that the camera focuses at infinity both before the lens stops
and before the infinity symbol, if that is any indication. Can
needing reading glasses affect this?

Has anyone computed a hyperfocal table specifically for this
camera? I wonder how much faith can be put in the focus range
markings on the lenses? Someone had made such a chart for the
RBT S1 and I reduced it and taped it to my camera and it is
often referred to.

The mounter is a complete cluster f , but does have a neat
light source as John mentioned. I think that I can adapt it
easily to the alignment gauge used by the SAM, but will need to
cut the lenses off at the base and add a spacer for better
focus.

Dale Yingst
Subject: Re: test for TL-120 (Chinese Camera) Users+ comments
Date: 2006-11-06 20:00:03
From: Sam Smith
--- In MF3D-group@yahoogroups.com, "Dale Yingst" wrote:
..
I haven't done the test Sam asked yet, but don't remember
> this being a concern in his initial impressions. I can say
> that the camera focuses at infinity both before the lens stops
> and before the infinity symbol, if that is any indication. Can
> needing reading glasses affect this?

This is an issue of the eyepiece, not of the viewfinder lens at the
front of the camera. Early models did not focus on the screen. I did
bring this up at NSA and in private emails, but this was between the
time when Paul's discussion list ended and mine began. I was actually
under the impression the issue was fixed (and it may be). I just want
proof before I receive the cameras I ordered!

I had emailed a few users recently asking if they were having any
problems with being able to see the screen sharply. The almost
unanimous response was " I can't tell - before I used a Sputnik"!!!

Sam
Subject: Re: test for TL-120 (Chinese Camera) Users+ comments
Date: 2006-11-06 21:35:11
From: Patrick Dube
>:-) The prism lock is not so great as mine has slid off twice
>already just from the general handling of the camera.

Mine does the same thing.


>The mounter is a complete cluster f , but does have a neat
>light source as John mentioned.

Does anyone knows if it can be powered by batteries?

Patrick

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Subject: TL-120 (Chinese Camera) lens filter diameter
Date: 2006-11-07 11:49:03
From: Dale Yingst
I reported my lens aperture misalignment to 3D World today. I
think it will be an easy do-it-at-home fix, but will wait for
their direction. Others may want to check their lenses.

Anyone know the filter diameter for this camera?

Dale Yingst
Subject: Re: TL-120 (Chinese Camera) lens filter diameter
Date: 2006-11-07 11:56:07
From: John Thurston
Dale Yingst wrote:
> Anyone know the filter diameter for this camera?

I think the inside of my lens cover
indicates 46mm. That said, I haven't actually
put a caliper on it or tried threading anything
onto the lenses to confirm.
--
John Thurston
Juneau Alaska
http://stereo.thurstons.us
Subject: Re: TL-120 (Chinese Camera) lens filter diameter
Date: 2006-11-08 00:20:53
From: Dale Yingst
John Thurston wrote:
>
>
> I think the inside of my lens cover
> indicates 46mm.
>
>

46mm it is. I just screwed a filter on.

Dale Yingst
Subject: Re: test for TL-120 (Chinese Camera) Users+ comments
Date: 2006-11-09 01:01:46
From: John Thurston
Dale Yingst wrote:

> Mine just arrived today.. . . The prism
> lock is not so great as mine has slid
> off twice already just from the general
> handling of the camera.

Mine hasn't dropped off the camera yet but
I know what you mean about the lock. When
I pick up the camera, I usually check to
make sure the prism is tightly in place.

I also have found the prism to be a very
handy place to grab the camera when I reach
for the camera in the bottom of my pack.
I am trying hard not to do this as I'm not
sure the prism attachment is designed to
suspend the full weight of the camera :)


> Has anyone computed a hyperfocal table
> specifically for this camera?

I have the test shots on my bench to
evaluate its depth of field. I just haven't
gotten out the loupe and my notepad yet.
To many projects, too little time.
________________________________________
John Thurston
Juneau, Alaska
http://stereo.thurstons.us
Subject: Re: Important test for TL-120 (Chinese Camera) Users
Date: 2006-11-10 17:41:57
From: John Thurston
Sam Smith wrote:

> It has been brought to my attention that a
> prior problem with the eyepiece of the
> Chinese TL-120 stereo camera MAY have not
> been corrected.

> 3. Point the eyepiece it out a window,
> making it a camera obscura. If a distant
> object at infinity is in sharp focus on
> the groundglass, you have a problem. If
> it is blurry and NOTHING is in focus, you
> should be OK. If something in the foreground
> is in focus, you really have a problem.

Due to Veteran's Day (aka Armistice Day) I have
had a happy coincidence of daylight, infinity
and camera.

My prism shows nothing in sharp focus when
the glass is placed directly on the bottom
of the prism. When I lift the glass just
a touch, I am able to focus tree branches
5-10 meters away.

Is this information of value to you, Sam?
________________________________________
John Thurston
Juneau, Alaska
http://stereo.thurstons.us
Subject: Re: Important test for TL-120 (Chinese Camera) Users
Date: 2006-11-10 21:58:32
From: Sam Smith
--- In MF3D-group@yahoogroups.com, John Thurston wrote:

> My prism shows nothing in sharp focus when
> the glass is placed directly on the bottom
> of the prism. When I lift the glass just
> a touch, I am able to focus tree branches
> 5-10 meters away.

What is important is finding where sharp infinity focus lies using the
eyepiece as reference. If when the ground glass (ground side towards
the prism of course) is placed on the flat of the pentaprism casing
and NOTHING is in focus, that should be good news, providing that
infinity actually comes into focus BEYOND the pentaprism casing. If
however you can get a sharp infinity image less than 4mm away from the
prism, the focal length is too short. It seems odd you can get a
closer image when the ground glass is away from the prism, but nothing
on it. In my case infinity was right at the pentaprism entrance, and
focusing on the screen (an extra 4mm away) required eyes that focused
BEYOND INFINITY, something my eyes are not capable of. Can you please
reconfirm there is absolutely nothing in focus at the pentaprism flat?
The camera I showed at NSA was modified by myself using a longer Kern
eyepiece.

What the whole point of this concern is, is to verify if the right
eyepiece was included with your camera. In my particular case, it was
incorrect twice. Another customer also had the same problem, and his
eyepiece was replaced. Unless distributors want to deal with recalls,
I'd strongly suggest you look into this. I just find it absolutely
baffling why I can't get a straight answer as to whether people can
sharply see the screen image or not. Do not judge by the microprism or
splitscreen as these can function when the screen is out of focus. You
must pay attention to the ground glass of the surrounding screen area.
It MUST be absolutely sharp when the image is in focus. I have been
fighting this issue for 5 months and am getting a little frustrated.
It's like ordering a red car and getting a green one, and the
technician explaining "It is red - you are just colorblind"!

Version three will be out soon, but those who ordered version two....

Sam
Subject: Re: Important test for TL-120 (Chinese Camera) Users
Date: 2006-11-11 10:59:31
From: Dale Yingst
I just tried your tape test on my prism and even though tape will not
give a great image, it appeared to be in focus. I just received my
camera . Will the microprism and split screen still work okay even
though the ground glass will be out of focus? Another item for me to
bitch about. I will post some internal pic tures tonight as I am
adjusting my lenses now. It's a nice day for shooting and I am not
going through another series of emails. They were very cordial, but as
yet not very helpful.

Dale Yingst
Subject: Important test for TL-120 (Chinese Camera) and MF comment
Date: 2006-11-11 15:19:31
From: Dale Yingst
Even though putting tape on my prism yielded an in focus image per Sam's
test request, when on the camera, the ground glass, microprism, and
split screen all seem to go into focus at the same point. So is
something still wrong?

Having shot very little MF, I have a couple questions. Since DOF is
less for MF, why are normal lenses used or in the case of the TL120
whose 80mm lens is maybe the equivalent of a 58mm lens for 35mm film?
It seems that many shooters in general like 35mm lenses on their 35mm
cameras if they could only have one lens. The 35 mm lenses on my RBT S1
seem to work in most situations with a little horizontal photographer
movement. Not so easy with the TL120 and its relatively narrow view.
So there is a smaller DOF and a farther near object at any Fstop if
infinity is included with the standard 75mm lenses and worse with the
TL120's 80mm. Also I would like to handhold sometimes and that becomes
marginal at 1/60 second exposures with 80mm lenses. And the stereo
effect with 80mm lenses at 63mm spacing is a little less I think.. So
wouldn't the whole system be improved by using shorter lenses, say 65mm
to 70mm? I know there had been talk about the importance of ortho
viewing, but it doesn't happen in 35mm usually. I prefer my MF viewing
through 65mm lenses. There has to be some reason for going to the
effort and expense of MF shooting, so I want my eyes right into the
images, not set back from them. I even like viewing through 58mm lenses,
but my optics are not too good. I've heard about Don Lopp's short FL
viewer but never looked through it.

Dale Yingst
Subject: TL-120 lensboard removal and adjust
Date: 2006-11-11 22:35:40
From: Dale Yingst
I can probably claim to be the least mechanically minded on this list,
but I removed the lens board and one lens today and adjusted it to match
the other taking viewfinder lenses. I have posted three photos to the
photos section. One shows the lens board off where you can clearly see
the aperture difference I was talking about with my camera. Only three
screws hold on each lens. I removed one lens as shown in another
picture. It was easy to adjust the aperture to match the other lens.
The problem is which aperture was actually at the right setting. From
looking at the marks(aperture and distance) on the lenses, I noticed
the finder and left lens always had the exact same symbols lining up,
where the right lens was a bit different. So I removed the right lens.
The aperture on the detached lens travels both smaller and larger than
the attached lens. A little playing around and the lenses are now in
perfect sync. When I get the ground glass from John, I will properly
calibrate the focus if needed. The markings on all three lenses line up
now and the aperture openings match.so I guess that is the best I can
hope for. I'm counting on the lens construction to be off better
automation and quality control than the hand assembly of the camera.
The aperture blades are not pristine though if you've noticed.

Anyhow it was nice to go out and shoot today.

Dale Yingst
Subject: Re: TL-120 lensboard removal and adjust
Date: 2006-11-12 00:24:38
From: Michael K. Davis
Dale,

Congratulations on your success as a shade-tree camera repairman. I salute
your courage and tenacity. My tinkering skills are so poor I wouldn't even
have allowed myself to loosen the first screw.

Mike Davis

At 09:26 PM 11/11/2006, you wrote:

>I can probably claim to be the least mechanically minded on this list,
>but I removed the lens board and one lens today and adjusted it to match
>the other taking viewfinder lenses.
Subject: Re: Important test for TL-120 (Chinese Camera) and MF comment
Date: 2006-11-13 22:42:41
From: roderickdsage
As I learned it, a normal lens is the same as film diagonal. a*square
x b*square /2 ..
So a 35mm camera normal lens is 43mm. 56x56 film would take an 80mm
lens. 80mm is normal for most 6x6 cameras, rarely 75mm. The cost of a
lens will go up as it gets wider for the given coverage.
Longer lenses should actually give more perception of depth than wider
lenses (at the same shooting distance), so should be an advantage with
narrow lens spacing. Consider the effect of foreshortening with
telephoto lenses (compression of depth). But then then there are the
problems with DOF, shutter speed etc...

Rod S

--- In MF3D-group@yahoogroups.com, Dale Yingst wrote:
>
>>
> Having shot very little MF, I have a couple questions. Since DOF is
> less for MF, why are normal lenses used or in the case of the TL120
> whose 80mm lens is maybe the equivalent of a 58mm lens for 35mm
film?
> It seems that many shooters in general like 35mm lenses on their
35mm
> cameras if they could only have one lens. The 35 mm lenses on my
RBT S1
> seem to work in most situations with a little horizontal
photographer
Subject: Re: Important test for TL-120 (Chinese Camera) Users
Date: 2006-12-17 11:15:46
From: David W. Kesner
--- In MF3D-group@yahoogroups.com, "Sam Smith" wrote:

> It has been brought to my attention that a prior problem with the
> eyepiece of the Chinese TL-120 stereo camera MAY have not been
> corrected. It appears the current stock may be using an eyepiece with
> too short a focal length, rendering the screen out of focus.

Sam, would this test be invalid with the new eye piece with diopter
correction? If not, what effect would adjusting the diopter show or
where should the diopter be set to do the test?

Thanks,

David W. Kesner
Subject: Important test for TL-120 Users & QUestions
Date: 2006-12-17 12:10:28
From: Dale Yingst
Dave K said,

> It appears the current stock may be using an eyepiece with
> > too short a focal length, rendering the screen out of focus.
>


Hello Dave,

My finder failed the test Sam asked us to do. I believe this just
affected the ground glass area and not the split finder and micro prism
area. Yet all three of my focusing areas come into focus at the same
point, so the finder seems to work correctly for my corrected(with
contacts) vision.

Could you answer a couple questions about this new model now that you
have had a chance to handle it? I noticed this model has 4 LEDs in the
finder where mine only has three. Since the fourth is separated from
the others, I wondered if that was a battery level indicator? Also mine
has two electric contacts at the front of the pentaprism where the new
ones have three contacts at the bottom of the pentaprism housing. Since
the metering cells are in the prism, has there been a change of
metering, maybe two cells now? BTW using the waist level finder disables
the metering. My tripod mount is not reinforced as yours is but still a
metal insert, secure enough for tripod shots but not for carrying it on
the tripod over your shoulder. *B*ut that would be pretty stupid with a
camera this heavy anyway. It's great that the improvements come so
quickly. I'm sure the lenses in the next batch will be flocked.

Thanks to whoever (Sam, 3DStereo?) is sending feedback to the company.
Maybe we should be doing the same.

I know most of you have camera packs, but I found a carry bag for the
TL120 that seems like it was custom made for it. Its the Quantaray Pro
C100 bag from Ritz:

http://www.ritzcamera.com/product/441663200.htm

The camera fits in like a glove, the bag is tall enough, well padded,
with both a hand carry strap and very well padded shoulder strap. A
great way to transport it. If I want to transport my S1 and/or P200
twin also, there is another Quantaray carry bag that works nicely.

These quick changes make me want to trade up already, but I think I'll
wait for version 5 (or 6) when they add the Shiatsu back massager and
ice maker.

Dale Yingst


>
>
Subject: One last question
Date: 2006-12-17 13:07:50
From: Dale Yingst
Dave K, one last question,

You said your finder fit very snuggly now. Mine and others are loose
because of the loose fit and the locking lever that is easily moved.
How is yours different?

Dale Yingst
Subject: Re: Important test for TL-120 Users & QUestions
Date: 2006-12-17 13:59:45
From: David W. Kesner
Dale Yingst writes:

> Could you answer a couple questions about this new model now that you have
> had a chance to handle it? I noticed this model has 4 LEDs in the finder
> where mine only has three. Since the fourth is separated from the others,
> I wondered if that was a battery level indicator?

I do not know as the manual they included is for the TL120-1 and shows
only three leds.

> Also mine has two
> electric contacts at the front of the pentaprism where the new ones have
> three contacts at the bottom of the pentaprism housing. Since the
> metering cells are in the prism, has there been a change of metering,
> maybe two cells now?

The manual says that metering "consists of two SPD's (silicon photo
diodes) for light measurement". But once again this is the TL120-1.

I just checked and the site still only has this manual in pdf for
download. Not sure when or if they plan to update to the TL120-2.

I still haven't got a chance to really play with this yet. Once I do I
can give more opinions and test results.

PS - what is the filter thread size?

Thanks,

David W. Kesner
Subject: Re: One last question
Date: 2006-12-17 14:01:37
From: David W. Kesner
Dale Yingst writes:

> You said your finder fit very snuggly now. Mine and others are loose
> because of the loose fit and the locking lever that is easily moved. How
> is yours different?

Not ever having seen the model 1 I am not sure how to answer this. Once I
get done with my NSA/ISU obligations this weekend I can look into it
further.

Thanks,

David W. Kesner
Subject: Re: One last question
Date: 2006-12-17 15:21:44
From: Dale Yingst
David W. Kesner wrote:
>
> Once I
> get done with my NSA/ISU obligations this weekend I can look into it
> further.
>



Well a simple little thing like a dual convention can't take THAT much
time :-)


DAle Yingst
>
>
>