Anamorphics

Aaron Shaw · January 27th, 2005, 09:19 AM

Thanks Emmanuel :)

My plan is to keep this as cheap as possible. Any actual profit will be a bonus in my eyes. It can be rather expensive to have custom lenses manufactured (which is a must for this sort of project). I'm just trying to gauge the general price range people are willing to spend so I can adjust the design to be maximally efficient for a target price range!

Ryan Koo · January 27th, 2005, 11:25 AM

I think the price point sort of depends on what 35mm lens mounting system becomes somewhat of an accepted and widespread system. For example, if James' Micro 35, which costs less than $100, does end up being very high quality, then you'll have a very hard time selling a $500 adapter to go anamorphic... In this situation I'd think it would have to come in at or under the $300 pricepoint... my 2 cents.

Aaron Shaw · January 27th, 2005, 11:34 AM

Excellent point. Perhaps a few quality options and varying price points would be best.

Justin Burris · January 27th, 2005, 06:38 PM

Aaron,

How versatile could we expect this to be? For instance, I have a full line of minolta primes (28, 35, 50, 85, 100, 135), plus a sigma 28-200 zoom (all in minolta mount). Would I be limited in what lenses I could use with your adapter? Would I expect to only be able to use a certain range of f-stops? Some of my lenses go all the way down to f1.4. I would hate to lose the lower stops in order to go anamorphic. Would I lose my close-focusing ability? Again, some of my lenses come as close as 12 inches in focusing. I would be willing to lose a little, but I don't want to go out to 3 feet like some of the front anamorphics.

Also, I would be looking for a 1.25x anamorphic. Would this be possible?

If I could have the 1.25x, use all of my lenses at all or most of their f-stops, still be able to focus pretty close, and have no chromatic abberation, I would probably pay $600.

Justin Burris · January 27th, 2005, 06:44 PM

Aaron,

By the way, have you considered an anamorphic lens behind the ground glass; in other words, between the ground glass and the video camera?

It seems like it would make the whole thing a lot easier for you to make, since you would only need to be able to focus on one plane: the ground glass. The lenses in front could do their own thing, uninhibited by the anamorphic process happening on the other side of the groundglass.

Do you know of reasons why this would not work?

Aaron Shaw · January 27th, 2005, 06:46 PM

Hi Justin. I don't have 100% solid answers for some of these questions yet but here is what I expect:

1) You should be able to use any prime or zoom lens you wish so long as they all have the same mount.

2) You would not be limited in the range of f-stops you can utilize. You WILL loose light though (this varies with the compression desired etc) - how much is yet to be seen. In any case, there should be no restriction on the ability to choose a specific f-stop.

3) I *believe* you should be able to retain the ability to focus up close. I don't see any reason why this would be affected. Something to test for sure.

Chromatic aberration is one of my main concerns and I will try to deal with it as best as possible.

Why a 1.25x? It could be done, just curious as to the reason for the specific compression :).

Justin Burris · January 27th, 2005, 06:50 PM

Aaron,

The Reel Stream Andromeda (also known as Juan's Mod) produces an image that is 990 DV pixels tall by 1546 wide. A 1.25x anamorphic will give me a 16:9 image.

Aaron Shaw · January 27th, 2005, 07:07 PM

Ah, ok! Maybe a means of changing the compression via some ring/lever would be a useful feature as well then.

Justin Burris · January 27th, 2005, 07:09 PM

You could do that?!!

In that case, I would want one to go from 1.25-1.66. Then I could have 16:9 and 2.35. Woo-hoo!!

The lever/ring would, of course, need markings and the ability to lock down somehow.

Aaron Shaw · January 27th, 2005, 07:15 PM

Oh yes, it's possible :). I don't know how much more it would cost. It's something I'll definitely look into though as I am sure others would find it of use as well.

Keith Kline · January 27th, 2005, 07:35 PM

Okay so here's the one thing that i'm not understanding. I know I'm stuck on the front mounted anamorphic, but it just seems like it would be easiest to mount/remove.

If it were a lens mounted with a rear filter ring to thread onto the front filter threading of the lens... why wouldn't it give the same compression on different lenses? I mean there are add on wide angle lenses that fit on standard 35mm lenses right? I mean those have a set magnification. Why would it be any different for an anamorphic lens.

Sorry, I just don't understand the difference. If someone could explain, that would be great.

Aaron Shaw · January 27th, 2005, 08:05 PM

Keith, the front anamorphic could be easier to mount/remove - you are right. However, if done correctly, the rear would not be any harder. One option is to have bayonet mounts on either end of the adapter so you would merely snap the adapter onto the 35mm mount and then the lens onto the adapter. The downside is you would have a slight increase in focal length.

Anway, on to your question:

Such a lens would indeed give the same compression regardless of which 35mm lens you used it on. The problem is that you would have to have a very large adapter to cover most of the diameters that 35mm lenses use. These can range anywhere from 45mm diameter to 90mm etc. It would just make a front system more complex to use, larger, and more expensive.

For a quick summary of the benefits and downsides to each type:

Front Anamorphic Disadvantages:

- Causes the lens to have two focal planes; one for each axis. Because of this you have to play around with both focal planes so they are both in focus at the same time. This can severly limit the ability to choose a specifc aperture and/or focal length for creative purposes (which partially defeats the purpose of a 35mm adapter in the first place).

- Can cause strong horizonal and/or vertical flare due to the lens shape and proximity to direct sunlight. Some people like the effect but it can also be rather annoying to have a huge flare across th entire screen from a light in the corner of the room.

- Very few matte boxes are designed to work with square lens shapes. Also, the wider anamorphics can cause severe vignetting unless you have a very, very wide mattebox.

- Limit your close focusing abilities due to multiple focal planes.

- Filters are harder to come by

- Need an adapter which can fit many different lens diameters. This causes the need for a very large diameter lens (and consequently more expensive/slower).

Rear Anamorphic Disadvantages:

- Out of focus points can become squarish instead of round. Some people find this to be bad others don't even notice. The amount varies. This effect can be seen in films such as "Apocalypse Now"

- More light loss. At least a 1/3 of a stop for 16:9 and more for higher compressions such as 2.35:1 (at least 2/3 of a stop)

- Depending on the mechanical design, could possibly extend the focal length of your lens slightly.

- Actually looses vertical field of view to create tha anamorphic image. Much like cropping the image in post but done optically so you don't loose res. This isn't a problem for most people as they would have cropped in post anway (again no resolution is lost only vertical field of view).

Front Anamorphic Advantages:

- Out of focus points are always oval in shape (note: not round as you would get with a straight 35mm spherical lens). Some prefer the stretched oval shape.

- Extends your view by approx 33% for a 16:9 adapter. This can be both good and bad actually. It can cause some strong barrel distortion at times.

Rear Anamorphic Advantages:

- Easy to use when made correctly. Just a simple piece between your lens and the body.

- Does not suffer from the strong artifacts that can plague front adapters in terms of distortion and flare.

- No need to have an adapter that can fit many lens diameters as it mounts to the rear.

- You can keep using your current matte box and accessories.

- Smaller, lighter, less expensive

I hope I remembered everything... I may update this if I realize I forgot something!

In any case, I think the rear has many advantages which make it more attractive. This is, of course, just my personal assessment.

Keith Kline · January 27th, 2005, 09:21 PM

Thanks for the info. Things are making alot more sense now. I know I don't know alot about how these systems work, but I'll help out with whatever i can.

Keith Kline · January 28th, 2005, 02:08 AM

Aaron, do you think it's possible to make either a front or rear mounted anamorphic conveter with a combination of existing lenses (cylinders, etc) or do you think the adapters would have to have custom made glass?

Oscar Spierenburg · January 28th, 2005, 06:25 AM

I know this tread is mostly setup for the pricing enquiry, but I have a technical suggestion or question.
I pointed out to make the lens shape of a clear lens filter and bend the anamorphic curve with a acryl (or other flexible) glass. This would be made waterproof on all edges. Now I suggested filling it up with water, but for the obvious risks I'm wondering if there is something within our reach to fill it up with something that will harden and turn it to a solid matter.

And Aaron, will the curves be different for a front or a rear lens?

January 28th, 2005, 02:08 AM	#29
Keith Kline Regular Crew Join Date: Aug 2004 Location: Akron, Ohio Posts: 153	Lenses Aaron, do you think it's possible to make either a front or rear mounted anamorphic conveter with a combination of existing lenses (cylinders, etc) or do you think the adapters would have to have custom made glass?

January 27th, 2005, 09:19 AM	#16
Aaron Shaw Major Player Join Date: Jul 2004 Posts: 587	Thanks Emmanuel :) My plan is to keep this as cheap as possible. Any actual profit will be a bonus in my eyes. It can be rather expensive to have custom lenses manufactured (which is a must for this sort of project). I'm just trying to gauge the general price range people are willing to spend so I can adjust the design to be maximally efficient for a target price range!

January 27th, 2005, 11:25 AM	#17
Ryan Koo Regular Crew Join Date: Mar 2004 Location: New York, NY Posts: 92	I think the price point sort of depends on what 35mm lens mounting system becomes somewhat of an accepted and widespread system. For example, if James' Micro 35, which costs less than $100, does end up being very high quality, then you'll have a very hard time selling a $500 adapter to go anamorphic... In this situation I'd think it would have to come in at or under the $300 pricepoint... my 2 cents.

January 27th, 2005, 11:34 AM	#18
Aaron Shaw Major Player Join Date: Jul 2004 Posts: 587	Excellent point. Perhaps a few quality options and varying price points would be best.

January 27th, 2005, 06:38 PM	#19
Justin Burris Regular Crew Join Date: Jan 2004 Location: Olympia, WA Posts: 54	Aaron, How versatile could we expect this to be? For instance, I have a full line of minolta primes (28, 35, 50, 85, 100, 135), plus a sigma 28-200 zoom (all in minolta mount). Would I be limited in what lenses I could use with your adapter? Would I expect to only be able to use a certain range of f-stops? Some of my lenses go all the way down to f1.4. I would hate to lose the lower stops in order to go anamorphic. Would I lose my close-focusing ability? Again, some of my lenses come as close as 12 inches in focusing. I would be willing to lose a little, but I don't want to go out to 3 feet like some of the front anamorphics. Also, I would be looking for a 1.25x anamorphic. Would this be possible? If I could have the 1.25x, use all of my lenses at all or most of their f-stops, still be able to focus pretty close, and have no chromatic abberation, I would probably pay $600.

January 27th, 2005, 06:44 PM	#20
Justin Burris Regular Crew Join Date: Jan 2004 Location: Olympia, WA Posts: 54	Aaron, By the way, have you considered an anamorphic lens behind the ground glass; in other words, between the ground glass and the video camera? It seems like it would make the whole thing a lot easier for you to make, since you would only need to be able to focus on one plane: the ground glass. The lenses in front could do their own thing, uninhibited by the anamorphic process happening on the other side of the groundglass. Do you know of reasons why this would not work?

January 27th, 2005, 06:46 PM	#21
Aaron Shaw Major Player Join Date: Jul 2004 Posts: 587	Hi Justin. I don't have 100% solid answers for some of these questions yet but here is what I expect: 1) You should be able to use any prime or zoom lens you wish so long as they all have the same mount. 2) You would not be limited in the range of f-stops you can utilize. You WILL loose light though (this varies with the compression desired etc) - how much is yet to be seen. In any case, there should be no restriction on the ability to choose a specific f-stop. 3) I believe you should be able to retain the ability to focus up close. I don't see any reason why this would be affected. Something to test for sure. Chromatic aberration is one of my main concerns and I will try to deal with it as best as possible. Why a 1.25x? It could be done, just curious as to the reason for the specific compression :).

January 27th, 2005, 06:50 PM	#22
Justin Burris Regular Crew Join Date: Jan 2004 Location: Olympia, WA Posts: 54	Aaron, The Reel Stream Andromeda (also known as Juan's Mod) produces an image that is 990 DV pixels tall by 1546 wide. A 1.25x anamorphic will give me a 16:9 image.

January 27th, 2005, 07:07 PM	#23
Aaron Shaw Major Player Join Date: Jul 2004 Posts: 587	Ah, ok! Maybe a means of changing the compression via some ring/lever would be a useful feature as well then.

January 27th, 2005, 07:09 PM	#24
Justin Burris Regular Crew Join Date: Jan 2004 Location: Olympia, WA Posts: 54	You could do that?!! In that case, I would want one to go from 1.25-1.66. Then I could have 16:9 and 2.35. Woo-hoo!! The lever/ring would, of course, need markings and the ability to lock down somehow.

January 27th, 2005, 07:15 PM	#25
Aaron Shaw Major Player Join Date: Jul 2004 Posts: 587	Oh yes, it's possible :). I don't know how much more it would cost. It's something I'll definitely look into though as I am sure others would find it of use as well.

January 27th, 2005, 07:35 PM	#26
Keith Kline Regular Crew Join Date: Aug 2004 Location: Akron, Ohio Posts: 153	Okay so here's the one thing that i'm not understanding. I know I'm stuck on the front mounted anamorphic, but it just seems like it would be easiest to mount/remove. If it were a lens mounted with a rear filter ring to thread onto the front filter threading of the lens... why wouldn't it give the same compression on different lenses? I mean there are add on wide angle lenses that fit on standard 35mm lenses right? I mean those have a set magnification. Why would it be any different for an anamorphic lens. Sorry, I just don't understand the difference. If someone could explain, that would be great.

January 27th, 2005, 08:05 PM	#27
Aaron Shaw Major Player Join Date: Jul 2004 Posts: 587	Keith, the front anamorphic could be easier to mount/remove - you are right. However, if done correctly, the rear would not be any harder. One option is to have bayonet mounts on either end of the adapter so you would merely snap the adapter onto the 35mm mount and then the lens onto the adapter. The downside is you would have a slight increase in focal length. Anway, on to your question: Such a lens would indeed give the same compression regardless of which 35mm lens you used it on. The problem is that you would have to have a very large adapter to cover most of the diameters that 35mm lenses use. These can range anywhere from 45mm diameter to 90mm etc. It would just make a front system more complex to use, larger, and more expensive. For a quick summary of the benefits and downsides to each type: Front Anamorphic Disadvantages: - Causes the lens to have two focal planes; one for each axis. Because of this you have to play around with both focal planes so they are both in focus at the same time. This can severly limit the ability to choose a specifc aperture and/or focal length for creative purposes (which partially defeats the purpose of a 35mm adapter in the first place). - Can cause strong horizonal and/or vertical flare due to the lens shape and proximity to direct sunlight. Some people like the effect but it can also be rather annoying to have a huge flare across th entire screen from a light in the corner of the room. - Very few matte boxes are designed to work with square lens shapes. Also, the wider anamorphics can cause severe vignetting unless you have a very, very wide mattebox. - Limit your close focusing abilities due to multiple focal planes. - Filters are harder to come by - Need an adapter which can fit many different lens diameters. This causes the need for a very large diameter lens (and consequently more expensive/slower). Rear Anamorphic Disadvantages: - Out of focus points can become squarish instead of round. Some people find this to be bad others don't even notice. The amount varies. This effect can be seen in films such as "Apocalypse Now" - More light loss. At least a 1/3 of a stop for 16:9 and more for higher compressions such as 2.35:1 (at least 2/3 of a stop) - Depending on the mechanical design, could possibly extend the focal length of your lens slightly. - Actually looses vertical field of view to create tha anamorphic image. Much like cropping the image in post but done optically so you don't loose res. This isn't a problem for most people as they would have cropped in post anway (again no resolution is lost only vertical field of view). Front Anamorphic Advantages: - Out of focus points are always oval in shape (note: not round as you would get with a straight 35mm spherical lens). Some prefer the stretched oval shape. - Extends your view by approx 33% for a 16:9 adapter. This can be both good and bad actually. It can cause some strong barrel distortion at times. Rear Anamorphic Advantages: - Easy to use when made correctly. Just a simple piece between your lens and the body. - Does not suffer from the strong artifacts that can plague front adapters in terms of distortion and flare. - No need to have an adapter that can fit many lens diameters as it mounts to the rear. - You can keep using your current matte box and accessories. - Smaller, lighter, less expensive I hope I remembered everything... I may update this if I realize I forgot something! In any case, I think the rear has many advantages which make it more attractive. This is, of course, just my personal assessment.

January 27th, 2005, 09:21 PM	#28
Keith Kline Regular Crew Join Date: Aug 2004 Location: Akron, Ohio Posts: 153	Thanks for the info. Things are making alot more sense now. I know I don't know alot about how these systems work, but I'll help out with whatever i can.

January 28th, 2005, 06:25 AM	#30
Oscar Spierenburg Major Player Join Date: Jan 2005 Location: (The Netherlands - Belgium) Posts: 735	I know this tread is mostly setup for the pricing enquiry, but I have a technical suggestion or question. I pointed out to make the lens shape of a clear lens filter and bend the anamorphic curve with a acryl (or other flexible) glass. This would be made waterproof on all edges. Now I suggested filling it up with water, but for the obvious risks I'm wondering if there is something within our reach to fill it up with something that will harden and turn it to a solid matter. And Aaron, will the curves be different for a front or a rear lens?