28mm Lens with Letus Econ. issue!

Have you heard from Letus about this? It does sound like you may have a defective adapter. Hien is usually pretty fast about resolving problems.
 
Mmmm...i just don't understand why the 50mm lens works and the 28mm doesn't....Doesn't make sense to me, since if this was a still camera, the lenses still need to focus on the same plane don't they?
 
Strange enough, I have a 28mm Nikon f2.8 and I have the same issue (had the same issue with the M2 and the Brevis as well); so I've given up on using this lens. I did speak with Hien and he also suggested just zooming in past the left screen darkness, but my 35mm achieves the same FOV.

Fortunately I have enough lenses to make up for the lack of a 28mm; I strongly suggest a 24mm lens (Nikon f2.0 is fantastic for Wide Angle).
 
disjecta said:
Have you heard from Letus about this? It does sound like you may have a defective adapter. Hien is usually pretty fast about resolving problems.
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I just emailed them this morning and I'm sure I'll get a response pretty quick.
 
DCP said:
Strange enough, I have a 28mm Nikon f2.8 and I have the same issue (had the same issue with the M2 and the Brevis as well); so I've given up on using this lens. I did speak with Hien and he also suggested just zooming in past the left screen darkness, but my 35mm achieves the same FOV.
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That's the thing -- If you zoom in so far then it really makes you wonder if it's worth getting a 28mm lens with this problem in mind. I used to have the Letus FE but never used a 28mm lens until now with the Economy. I'm really bummed about this since I would like to shoot some scenes in a car with a wide angle lens.
 
MalcolmOng said:
Mmmm...i just don't understand why the 50mm lens works and the 28mm doesn't....Doesn't make sense to me, since if this was a still camera, the lenses still need to focus on the same plane don't they?
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The only thing I can think of is that the narrow path of the 28mm lens with which the adapter has to see through is... well... too narrow with the Economy. I mean the 50mm and 200mm barrel are so wide compared to it. I don't know. I'm not a lens wizzard.
 
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I don't know if someone already asked this, but this are thing easily overlooked.

Is your lens made for a digital 35 mm still camera?

Digital lenses don't need to cover as mush area as the still film cameras.

Is your adapter perfectly perpendicular?
 
Is the lense flush against the mount? Its weird that it would off center like that. I also have a 28mm that works fine on any adapter i put it on.
 
jgastelb said:
This is the second one I got.

http://www.keh.com/OnLineStore/Prod...CC=&CCC=&BCL=&GBC=&GCC=&KW=canon 28mm fd lens
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If you don't change anything you'll get the same results.

That is an economical lens. It is made for digital 35 that means that it doesn't cover the 36 mm X 2 mm required by the adaptor or a 35 mm film still camera.

Ask someone to lend you a lens made for a 12 MP full frame camera and see.

It seams to me that the problem is the lens, but what do I know.
 
Douglas Villalba said:
If you don't change anything you'll get the same results.

That is an economical lens. It is made for digital 35 that means that it doesn't cover the 36 mm X 2 mm required by the adaptor or a 35 mm film still camera.

Ask someone to lend you a lens made for a 12 MP full frame camera and see.

It seams to me that the problem is the lens, but what do I know.
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I'm sorry but I didn't know anything about what you're talking about. I was told by the Letus guys that provided one would get a Canon fd lens then things would be peachy. I got my other lenses (50mm & 2000mm) from KEH.COM and haven't had a problem with those. So what gives here?
Jgastelb
 
Simply put most of the new digital cameras are not full size 35 mm (36 mm X 24 mm). For this reason lens manufactures make inexpensive lenses that only work with the less expensive cameras (Revel etc.). When you use this lenses on cameras that have full 36 mm X 24 mm film plane (including 35 mm adaptors of any brand) they vignette. In other words they don't fill the whole screen.

I haven't kept up with photography for the past 15 years, but this much I know.

I can't know for sure in your case, but. You have 2 lenses that work fine and you have two equal lenses doing the same vignette. That points to the that particular 28 mm lens.

You also seem to have a problem with the CCDs on your camera being off center. A lot of cameras have this problem. You can never tell with the normal lens because the rear projection of the normal lens is wide enough that you'll never notice it.

I hope this helps.
 
Douglas and Jgastelb,

FD lenses cover the full 35mm frame. Canon discontinued the FD mount long before they ever even created a digital slr so there's no way that an FD lens could be designed for a reduced frame digital sensor.

When Canon makes a reduced frame lens they give it the EF-S label. Nikon's digital lenses are DX. Someone correct me if I'm wrong but I think we can rule out the hypothesis that you're using the wrong type of lens. Although, as mentioned, there could still be something wrong with that particular lens. Do you have a still camera on which you can test it?

all the best
davide
 
davide said:
Douglas and Jgastelb,

FD lenses cover the full 35mm frame. Canon discontinued the FD mount long before they ever even created a digital slr so there's no way that an FD lens could be designed for a reduced frame digital sensor.
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This is my understanding as well here. The FD 28mm lens should in theory work just as well the 50mm or 200mm.
 
Douglas Villalba said:
You also seem to have a problem with the CCDs on your camera being off center. A lot of cameras have this problem. You can never tell with the normal lens because the rear projection of the normal lens is wide enough that you'll never notice it.

I hope this helps.
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Thanks! I don't think my CCD is off center. What's off is the Letus frame. I don't mind this as much since I usually zoom past this. With the 28mm, however, it can be a pain since you still get strong vignette.
 
Douglas Villalba said:
Simply put most of the new digital cameras are not full size 35 mm (36 mm X 24 mm). For this reason lens manufactures make inexpensive lenses that only work with the less expensive cameras (Revel etc.). When you use this lenses on cameras that have full 36 mm X 24 mm film plane (including 35 mm adaptors of any brand) they vignette. In other words they don't fill the whole screen.

I haven't kept up with photography for the past 15 years, but this much I know.

I can't know for sure in your case, but. You have 2 lenses that work fine and you have two equal lenses doing the same vignette. That points to the that particular 28 mm lens.

You also seem to have a problem with the CCDs on your camera being off center. A lot of cameras have this problem. You can never tell with the normal lens because the rear projection of the normal lens is wide enough that you'll never notice it.

I hope this helps.
Click to expand...

FD lenses were a thing of the 80's and I'm pretty sure digital SLR's weren't snapping pics back then. I have a Canon A1 with various FD lenses and it's a great camera, full frame and very much a manual system.

It's possible the 28mm lens needs to be physically further forward when mounted to the front of the Letus adapter. Like a projection, the image gets bigger the further the distance between the glass in the lens and the screen it's projecting the image onto.
You may need to put some spacers between the Letus and the lens..
Dunno, may work, may just be some serious bad luck for you... That's my 2 cents worth :)
 
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