8mm Forum: iscorama 42

»	8mm Forum » 8mm Forum » iscorama 42

UBBFriend: Email this page to someone!

Author

Topic: iscorama 42

Louis Li
Expert Film Handler

Posts: 159
From: SG
Registered: Feb 2007

posted May 12, 2008 05:34 AM

am planning to purchase the iscorama 42mc 1.5x
mainly for shooting.

on researching on the lens, i found some thing a little different on the focusing of this lens.
that is the camera's lens is always at infinity while you focus distance through the anamorphic?
i remember john whittle once mention to me to focus both camera lens and anamorphic. so i need some clarification.
i wonder if this is just unique to the iscorama's?
in a way i guess its user friendly, less hassle.

on another note. regarding scope prints. they are usually 2x?
if i were to project scope prints with this lens.
i guess there will be a slight squeeze to it.
is that ok?

thanks for your help.

| IP: Logged

Jan Bister
Darth 8mm

Posts: 2629
From: Ohio, USA
Registered: Jan 2005

posted May 12, 2008 09:14 AM

As far as I know, all super-8 scope prints are 2:1 so you'll still get a visible squeeze to the image... although it beats not having a scope lens at all. [Wink]

Not sure about the focusing part when shooting with the Iscorama lens... I think both is correct: when projecting, you focus both the prime and anamorphic lens, but when shooting, the camera lens stays at infinite and the anamorphic lens is used to focus.

I could be wrong, though...

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

John Whittle
Jedi Master Film Handler

Posts: 791
From: Northridge, CA USA
Registered: Jun 2003

posted May 12, 2008 07:43 PM

Which lens are you looking at purchasing? Do you have a link to some specs? Normally when I shot with either a Moller, Sankor, Kowa or Panavision Superama, I'd focus the camera prime lens first then put the adapter lens in front and focus for the final image. It doesn't seem right that you'd leave the camera lens at infinity unless they figure you're shoot distant landscapes.

I have a still camera set-up with a 1.5x lens which is an Iscorama and it fits on it's own lens and they made them for Nikon, Canon etc back in the 50s. You could use these with a movie camera if you used a Nikon to C mount adapter. Something I was planning on doing someday.

As for the compression ratio. All commercial scope films now are 2x. The size of the 35mm frame yields the 2.4:1 image. If you shoot with a 1.5x lens, you should project with a l.5x lens which in Super8 or 16mm would give you a 1.33 x 1.5 or 2:1 picture size.

Most of the anamorphic lenses sold for personal use in the 1950s and 60s were 1.5x which includes the Bolex Moeller, The Vistascope (although they did make a 2x 16mm version as well) and a little Yashicascope lens.

However the Bell & Howell 16mm Filmoscope lens (not the Kowa which came later) was 2x and designed for photography and projector. It sold for about 600 dollars back in the 1950s which would be several thousand in today's dollars. I guess they were trying to recoup their engineering costs but didn't sell many lenses and when it was copied/replicated by the Japanese lens makers they lost out.

John

| IP: Logged

Louis Li
Expert Film Handler

Posts: 159
From: SG
Registered: Feb 2007

posted May 13, 2008 10:47 AM

i found some specs on the lens

NAME: ISCORAMA 42
Compression Factor: 1.5x
Maximum length (front to rear): 83.0mm
Front diameter (outside): 87.0mm
Filter thread: 82.0mm
Rear element diameter: 42.0mm
Rear barrel diameter: - ? -
Rear barrel thread: 62.0mm
Weight: 750g
Focusing range: 2m-infinity

| IP: Logged

John Whittle
Jedi Master Film Handler

Posts: 791
From: Northridge, CA USA
Registered: Jun 2003

posted May 13, 2008 10:23 PM

I think that's the same lens I have. The anamorphic is just one of three parts of the system. There is a prime back up lens for the camera with an iris. The anamorphic snaps into it and has a focusing ring.

Then there is a slide projector lens that the anamorphic is used with for projection.

I don't think you'd use the anamorphic alone for photography, but with the prime and lens and a suitable "C" mount adapter you could use it on a 16mm camera.

For projection you'd have to choose a different adapter such as the prism Panavision 16 which adjusted for 1.5 and 2x or the Vistascope or the Bolex Moeller.

Bolex did make an anamorphic for the standard 8mm cameras and projector which fitted the H-8 and B-8 cameras and p-8 projector. Complete brackets, viewfinders, etc. Of course none of these would work with a zoom lens because the zoom lens would vingette by photographing inside the anamorphic lens.

John

| IP: Logged

Louis Li
Expert Film Handler

Posts: 159
From: SG
Registered: Feb 2007

posted May 15, 2008 11:43 AM

john i think ill just test the lens with my primes, and hope for the best. i don't see a problem fitting it like a normal A-lens. (just in front of the camera lens)

however, i want to ask about the bracket to hold the A-lens for the camera. usually, do people just custom make one from some metalwork factory? majority of brackets i see seem to have a similar "holding A-lens ring attached to a rod attached to the base of the camera"

| IP: Logged

John Whittle
Jedi Master Film Handler

Posts: 791
From: Northridge, CA USA
Registered: Jun 2003

posted May 15, 2008 08:17 PM

Coming up with a bracket depends on the camera. With the Bolex H series, two rods were placed in the turret lens places and then a bracket slid on those rods to align the adapter with the prime lens.

The Iscorama lens actually clips into the 50mm prime lens they made for the camera. That spring loading allows you to rotate it for proper orientation. With a SLR camera the aspect ration is 3:2 or 1:1.5 and with the 1.5x lens it becomes 4.5:2 or 1:1.25 of very close to Cinemascope. With 8mm or 16mm with a 1.33 aspect ratio it become 2:1.

If you have a reflex camera, check out the lens through your viewfinder and see what you're getting. Some lenses were afixed with a slip ring that screwed into the filter threads. The problem with this is it puts a great deal of stress on the lens mount to the camera. If you have a Bolex or Arri with bayonette mount it shouldn't be a problem but with a C mount of D mount 8mm lens it could be a problem. Also with a zoom you run the risk of the delicate often plastic gears inside the lens being stressed and deformed so keep that in mind when testing and try and support the adapter apart from the prime lens.

John

| IP: Logged

All times are Central

Printer-friendly view of this topic

UBB.classic^TM 6.3.1.2