Hello,
I recently purchased, not receive yet MTV-3 adapter. I struggle to build my camera setup, based on Sony NEX, for Olympus LB objectives and NFK relay lens.
As I am not so desperate to fight for NFK 1.67 (and I would like to have also more FOV recorded on APS-C sensor, than 1.67 offers), I figured out that circa 1x relay lens is what I need.
My latest trial is to combine NFK 3.3x which I luckily have with 0.3x MTV-3...
Unfortunately, MTV-3 I bought is without silver top c-mount adapter and I am looking for help to get nice drawing or dimensions of one, especially along vertical axis, to assure proper registration distance when I will build my own.
What do you generally think about such combination?
I have c-mount adapter for NEX, which has also M42 thread (very close to camera body) and that is where I put my attention or maybe to combine with m39 adapter (where I could remove m39 thread ring and replace with simple - custom adapter for MTV-3) if registration distance allows.
Best Regards!
Olympus MTV-3
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Re: Olympus MTV-3
The MTV-3 was designed for C-mount cameras with sensors no more than 16mm diagonal. This is not a suitable starting point for attaching a Sony NEX with an APS-C sensor.kriscavok wrote:I recently purchased, not receive yet MTV-3 adapter. I struggle to build my camera setup, based on Sony NEX, for Olympus LB objectives and NFK relay lens.
I suggest trying to cancel your purchase, and look for an Olympus Photomicro Adapter L instead. This was intended for attaching Olympus OM cameras, and you can buy adapters to convert OM lenses to fit NEX cameras.
Then try ChrisR's suggestion of a 2x photo converter; you can buy Olympus OM ones cheaply on eBay.
Alan Wood
Thank you for answer,
My deeper idea is to try if MTV-3 would project circle bigger than 16mm, even only little bigger would be fine for me.
Personally prefer to have whole or most of FOV recorded on the sensor (picture with "cut corners" would be optimum), than have sensor fulfilled wit partial field of view.
In fact I got inspired by your great website where you mention that MTV-3 was designed to deliver 16mm circle coupled with nfk 2.5x . I really like to experiment how it would be with 3.3x.
I am going to try first how MTV-3 will behave when not obstructed by silver c-mount camera adapter, which is kind of field stop in the system.
I will still really appreciate measurements of silver c-mount adapter for proper registration distance.
Regards!
My deeper idea is to try if MTV-3 would project circle bigger than 16mm, even only little bigger would be fine for me.
Personally prefer to have whole or most of FOV recorded on the sensor (picture with "cut corners" would be optimum), than have sensor fulfilled wit partial field of view.
In fact I got inspired by your great website where you mention that MTV-3 was designed to deliver 16mm circle coupled with nfk 2.5x . I really like to experiment how it would be with 3.3x.
I am going to try first how MTV-3 will behave when not obstructed by silver c-mount camera adapter, which is kind of field stop in the system.
I will still really appreciate measurements of silver c-mount adapter for proper registration distance.
Regards!
KrisCavok
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rjlittlefield
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I'm not sure exactly what the question is asking, but see if this helps...ChrisR wrote:This may be not-helpful, but I always wondered, what a projection eyepiece actually does that's different from a teleconverter. M42, 2x, is rather easy in those!
A teleconverter is a Barlow lens. Its optics sit entirely in front of the original image plane. The lens acts to push the image plane back so the image gets bigger but does not invert.
A projection eyepiece -- as diagrammed at MicroscopyU -- is like an ordinary eyepiece that has been raised a bit. Most of its optics sit behind the original image plane and act to re-project it to form a second real image that is inverted with respect to the first. This type of eyepiece can be made in any magnification, enlarging or reducing.
My description of the inversions here is probably confusing. They are with respect to the real image formed by the objective. But when you compare what the camera sees versus what your eye would see through a normal eyepiece, it's the Barlow lens that inverts and the raised eyepiece that does not. Sigh...
In theory, a projection eyepiece could also be made using the principle of a Barlow lens. In that case most or all of the optics would sit pretty far down in the tube. But this arrangement can only enlarge, not reduce, and I don't know which (if any) projection eyepieces go that route.
--Rik
Re: Olympus MTV-3
Rik is correct, of course. A 2x tele converter would make an Olympus NFK 3.3x photo eyepiece behave like a 6.6x, not like a 1.65x.Alan Wood wrote:Then try ChrisR's suggestion of a 2x photo converter; you can buy Olympus OM ones cheaply on eBay.
The distance from the ledge on which the top part of the NFK rests to the film/sensor is 150.0 mm, but you want to add another lens to reduce the image and so this distance is not relevant.
As you know, the NFK incorporates corrections for the LB objectives, and so any extra reducing lens that you add should be a well-corrected achromat. It should not try to correct the objective.
The Sony NEX sensor is 23.4 × 15.6mm (according to Wikipedia), and the circular image from a complete MTV-3 with an NFK 2.5x is about 16mm diameter (my measurement). However, the lens in the MTV-3 is designed for a C-mount camera with a much shorter lens flange to sensor distance than the Sony NEX.
It looks as though it would be possible to use an MTV-3 with a Nikon 1, because it has a 16mm diameter sensor and can be adapted to use C-mount lenses. I do not know if anyone has tried this combination.
As we are all learning, there does not seem to be a way of using a camera with an APS-C sensor on an Olympus microscope that is easy and good and cheap.
Alan Wood
About afocal, take a look at
http://www.photomacrography.net/forum/v ... hp?t=15607
If when you put a normal viewing eyepiece at the photoport the visual image is parfocal with the binocular one, afocal will be easy, you just need the adequate Olympus compensating eyepiece (WHK?) and a camera lens over it.
The relay magnification is:
eyepiece magnification X camera lens focal lengh / 250
For APSC to get 1.6X two good combinations are
- 8X eyepiece and 50mm camera lens
- 10X eyepiece and 40mm camera lens
If interested, take a look to other posts like:
http://www.photomacrography.net/forum/v ... 387#128387
It will end for sure less elegant that a 1.67NFK and a Photomicroadapter L, but IMO it will work very well.
http://www.photomacrography.net/forum/v ... hp?t=15607
If when you put a normal viewing eyepiece at the photoport the visual image is parfocal with the binocular one, afocal will be easy, you just need the adequate Olympus compensating eyepiece (WHK?) and a camera lens over it.
The relay magnification is:
eyepiece magnification X camera lens focal lengh / 250
For APSC to get 1.6X two good combinations are
- 8X eyepiece and 50mm camera lens
- 10X eyepiece and 40mm camera lens
If interested, take a look to other posts like:
http://www.photomacrography.net/forum/v ... 387#128387
It will end for sure less elegant that a 1.67NFK and a Photomicroadapter L, but IMO it will work very well.
Pau