Chamonix H-1 and Imagon 250mm

[olk]

Hi,
I'm confused because I got an Imagon 250mm and I've ordered a Chaminix H-1 (not shipped yet).
The previous owner of the Imagon told me that he was forced to buy an extension for his Sinar F2 - otherwise he couldn't get in focus.

My intention was to use the H-1 with the Imagon for portaits (2,5m - 3m distance to the subject). I've calculated that the focus plane will be at 273mm.
Is that correct?

At the H-1 the bellows can be extended up to 340mm. So I see no reason why it shouldn't work. Maybe the standard rail length of the Sinar F2 is too short?

Oliver

[Tin Can]

Try it and come back

I could test combo. but I am one handed right now

[drew.saunders]

Ebony Camera, before they closed up, had a great page called "Lens Compatibility" that you can still get through the Wayback machine. Here's a good version: https://web.archive.org/web/20161215002237/http://www.ebonycamera.com/articles/lenses.html

Anyway, the flange focal distance, or Flange Back in that chart, of the 250mm Imagon is 276mm. That means to get to infinity, you have to be racked out to 276mm, not 250mm as you might expect for a 250mm lens. If you look at that page, you'll see that most lenses have a Flange Back a bit shorter than the focal length, but the Imagon has all its elements behind the shutter, so needs more extension. What this means is that your bellows are effectively 26mm "short," so to focus at 2500mm, which requires 278mm of bellows extension for a 250mm lens, but with the 276mm flange back of the Imagon, means you have to rack the bellows out to 304mm. With 340mm of bellows, your minimum focus is around 1.22m.

That's a lot of math to say: It should work just fine.

I had both my 250mm Fujinar and 250mm Imagon with me recently, and composed an image with the Fujinar, then decided to try it with the Imagon, and was surprised at how much I had to rack the bellows out to get the same image back into focus.

[John Brady]

If you find you need more extension than your camera allows you can get an extension board to mount the lens to, assuming you don’t have to extend too much.

[Alan Klein]

Check with Hugo, Chamonix's rep.
hugo zhang <hugoz_2000@yahoo.com>

[olk]

If you find you need more extension than your camera allows you can get an extension board to mount the lens to, assuming you don’t have to extend too much.

Unfortunately the H-1 can not be extended.

[olk]

Anyway, the flange focal distance, or Flange Back in that chart, of the 250mm Imagon is 276mm. That means to get to infinity, you have to be racked out to 276mm, not 250mm as you might expect for a 250mm lens. If you look at that page, you'll see that most lenses have a Flange Back a bit shorter than the focal length, but the Imagon has all its elements behind the shutter, so needs more extension. What this means is that your bellows are effectively 26mm "short," so to focus at 2500mm, which requires 278mm of bellows extension for a 250mm lens, but with the 276mm flange back of the Imagon, means you have to rack the bellows out to 304mm. With 340mm of bellows, your minimum focus is around 1.22m.
That's a lot of math to say: It should work just fine.

Thank you - I missed to take into account that the lens is mounted at the back of the shutter.
I'm wondering because with f=276mm I get a little bit different distances (312,5mm for 2.5m distance). I used the simple lens formula: 1/b + 1/c = 1/f (b: distance subject, c: distance image, f: focal length).

[Bernice Loui]

What are the image goals?

Single image ratio case calculations apply to one specific image making example, which will vary LOTs with each and every other image making endeavor.

If the 250mm Imagon is used at infinity focus, those calculated numeric values for camera extension/bellows apply for one specific image case (infinity).
If the 250mm Imagon (or virtually any 250mm lens) is used for head/shoulder portraits, the camera/bellows extension could easily exceed the capability of 340mm. If the 250mm Imagon is used for close-up life-size aka 1:1 camera/bellows extension will exceed 500mm.

The mind-set of camera first, lens and all much less significant appears to be a carry over from fixed lens box type cameras (makes zero difference with brand or model or style or etc) does not apply to the view camera world.

If the image goals are to use this 250mm Imagon for head/shoulder portrait images, not gonna work. Images at infinity should be ok. Slight increase in camera/bellows extension can be had by using a "top hat" lens board.

These are some of the very real limitations of a lightweight field folder view camera.


Sinar F2, F, P, Norma or ... can be camera/bellows extended as needed. Adding a rail extension costing about $50 can add 6" to 18" of rail extension, adding more rail extension results in Sinar set up like this.
219633

Or

219634

Bellows are simply added with a front standard or "aux" standard as needed.

The "forced" of adding rail/bellows extension is completely lens dependent, camera serves this need. If the camera is unable to serve the needs of lens and image ratio needed, image goals cannot be met.


Bernice






Hi,
I'm confused because I got an Imagon 250mm and I've ordered a Chaminix H-1 (not shipped yet).
The previous owner of the Imagon told me that he was forced to buy an extension for his Sinar F2 - otherwise he couldn't get in focus.

My intention was to use the H-1 with the Imagon for portaits (2,5m - 3m distance to the subject). I've calculated that the focus plane will be at 273mm.
Is that correct?

At the H-1 the bellows can be extended up to 340mm. So I see no reason why it shouldn't work. Maybe the standard rail length of the Sinar F2 is too short?

Oliver

[Tin Can]

I will trade a 4X5 Norma for that piece of junk H1

Really:cool:

[olk]

If the 250mm Imagon (or virtually any 250mm lens) is used for head/shoulder portraits, the camera/bellows extension could easily exceed the capability of 340mm.
Is this a guess or did you calculate that more than 340mm bellows extension is required for the Imagon (focal length nominal 250mm but as Drew mentioned it is actually 276mm) for head/shoulder portraits?

Oliver

[Bernice Loui]

Point being, calculations are not as useful as one might believe due to the unpredictability of how images and their required image ratios vary all over the place due directly to the nature of view camera lenses which do NOT have a fixed back focal length as with fixed lens box based cameras.

At some point it is quite possible a lens with longer than 250mm / 10" focal length could be needed. Once above 300mm, the bellows/camera extension of 370~ mm will prove to be no where near enough.

These are the very real world limitations of a light weight field folder cameras that modular monorail cameras simply do not have. Camera choice is completely dependent on lenses needed to achieve the image goals and what hardware is required to achieve the expected image goals.


Bernice




Is this a guess or did you calculate that more than 340mm bellows extension is required for the Imagon (focal length nominal 250mm but as Drew mentioned it is actually 276mm) for head/shoulder portraits?

Oliver

[Bob Salomon]

Point being, calculations are not as useful as one might believe due to the unpredictability of how images and their required image ratios vary all over the place due directly to the nature of view camera lenses which do NOT have a fixed back focal length as with fixed lens box based cameras.

At some point it is quite possible a lens with longer than 250mm / 10" focal length could be needed. Once above 300mm, the bellows/camera extension of 370~ mm will prove to be no where near enough.

These are the very real world limitations of a light weight field folder cameras that modular monorail cameras simply do not have. Camera choice is completely dependent on lenses needed to achieve the image goals and what hardware is required to achieve the expected image goals.


Bernice
Except Wista that makes extension beds and bellows for their field and technical cameras.

[Bernice Loui]

Ok Bob, I'll bite.... once.

Well Bob, how much "extension" could be put on a Wista field folder... 2000mm or more possible?


Bernice


Except Wista that makes extension beds and bellows for their field and technical cameras.

[Bob Salomon]

Ok Bob, I'll bite.... once.

Well Bob, how much "extension" could be put on a Wista field folder... 2000mm or more possible?


Bernice

Believe max is about 2000mm.

[Bernice Loui]

How about 6,000mm Bob?

Bernice



Believe max is about 2000mm.

[Bob Salomon]

How about 6,000mm Bob?

Bernice

Been too long since I sold them but there could be a 6K bed and bellows.

[drew.saunders]

Thank you - I missed to take into account that the lens is mounted at the back of the shutter.
I'm wondering because with f=276mm I get a little bit different distances (312,5mm for 2.5m distance). I used the simple lens formula: 1/b + 1/c = 1/f (b: distance subject, c: distance image, f: focal length).

Focal length is still 250mm, so to focus at 2500mm, it’s
1/250 - 1/2500 = 0.0036
1/0.0036 = 277.77777

You need to rack out 28mm from your starting point of 276mm or 304mm.

Telephoto lenses work the other way, your starting point is much less than the focal length, but any 250mm lens focused at 2500mm needs to move the rear nodal point forward 28mm, whether by bellows, focusing helicoid, or internal focusing wizardry of modern lenses.


Sent from my iPad using Tapatalk

[olk]

You need to rack out 28mm from your starting point of 276mm or 304mm.

thanks, I got it.

So I've to think about the camera. The Chamonix H-1 can not be extended and the F2 is in stock in 4 months (or maybe later) ...

A Sinar F2 is suitable but heavier - portable/lightweight enough for hiking (photographing landscape)?

[Oslolens]

Change the focal length if the camera is not long enough. A +1 diopter could be what you need if you don't want to use a prolonged lens board.
I am sure someone can present a distance piece for the back in a couple of weeks ;)

Sent fra min SM-G975F via Tapatalk

[Bernice Loui]

All view cameras are a fixed set of trade offs, there IS NO ideal view camera for all image making needs.

~If you're back packing long distances for very extended durations, this image making needs mostly demands a light weight field folder with small light weight lenses, tripod and all related view camera items to meet this requirement. Traded off, large aperture lenses that are not light weight, camera with limited movements with limited camera/bellows extension and camera/bellows compression to allow using wide angle lenses with significant camera movement.

~Monorail camera such as the Sinar F2 has FAR more camera/bellows extension and camera compression, camera movements than ANY field folder. This allows using nearly ANY optic in the Sinar system. Couple this with the Sinar shutter allows using barrel lenses. Modularity allows configuring the camera as needed to meet most any view camera image making need. Sinar monorail system is no where near as compact/foldable as a lightweight field foldable and can never be folded up into essentially a box for compact and ease of transport.

Take the time to read this before deciding.
https://www.largeformatphotography.info/forum/showthread.php?164634-Sinar-F2-Vs-Sinar-Norma-(4x5)


Again, primary or top priority is deciding the kind of images you're interested in making, the lenses-optics needed to achieve this, then consider which style of view camera meets the majority of these needs and demands most.



Bernice



thanks, I got it.

So I've to think about the camera. The Chamonix H-1 can not be extended and the F2 is in stock in 4 months (or maybe later) ...

A Sinar F2 is suitable but heavier - portable/lightweight enough for hiking (photographing landscape)?

[Bob Salomon]

All view cameras are a fixed set of trade offs, there IS NO ideal view camera for all image making needs.

~If you're back packing long distances for very extended durations, this image making needs mostly demands a light weight field folder with small light weight lenses, tripod and all related view camera items to meet this requirement. Traded off, large aperture lenses that are not light weight, camera with limited movements with limited camera/bellows extension and camera/bellows compression to allow using wide angle lenses with significant camera movement.

~Monorail camera such as the Sinar F2 has FAR more camera/bellows extension and camera compression, camera movements than ANY field folder. This allows using nearly ANY optic in the Sinar system. Couple this with the Sinar shutter allows using barrel lenses. Modularity allows configuring the camera as needed to meet most any view camera image making need. Sinar monorail system is no where near as compact/foldable as a lightweight field foldable and can never be folded up into essentially a box for compact and ease of transport.

Take the time to read this before deciding.
https://www.largeformatphotography.info/forum/showthread.php?164634-Sinar-F2-Vs-Sinar-Norma-(4x5)


Again, primary or top priority is deciding the kind of images you're interested in making, the lenses-optics needed to achieve this, then consider which style of view camera meets the majority of these needs and demands most.



Bernice

It does not have “far more movement” then say a LInhof TK 45 or the TK 45S. And the TK has separate locks for all movements front and back.

[Bernice Loui]

Meh, Bob. Cannot stop the Linhof marketing promo stuff..

Linhof TK IS a monorail variant, no?


Bernice


It does not have “far more movement” then say a LInhof TK 45 or the TK 45S. And the TK has separate locks for all movements front and back.

[Bob Salomon]

Meh, Bob. Cannot stop the Linhof marketing promo stuff..

Linhof TK IS a monorail variant, no?


Bernice

Folding monorail.

[Bernice Loui]

Monorail....





Folding monorail.