I don't think we should propose it as something they should consider adding to their catolog, or marketing to dv enthusiasts, we should approach it as requesting them to make a certain amount for our purposes and requesting a price quote.

My opionion is that this is an alternative to going to a machine shop. A place you give your specs and they build what you need, because they have the tools and expertise.

Sigma is in the same position as that, except they build lenses, that is what they do. We do not need them to do massive R&D. We give them the specs, they should know how to accomplish it without any R&D.

We need way to attach it to our cameras, some sort of xl mount. We need a lens that will allow our cameras to capture a 36x24mm frame off of a gg, and a mount in front of that gg at the correct flange depth. To a lens maker, this may be a strange request, but certainly not difficult or prohibitively expensive. There are no moving elements, everything could be locked down.

Xl mount could be a problem if it needs to be licensed. for the front element, I would vote c-mount or f-mount. Im not terribly interested in sigma lenses, but as you say, it may be a selling point for them.

stephen

by the way, I've read in other threads where people have arranged this sort of deal with japanese lens manufactureres, this is why I am optomistic..

not 100% sure, but it seems if they will send you the relay lens, than all you need is to build the gg and mount in front of it. if you look at the pdf of the innards of the lens, you can probably deduce where the "relay" ends and the gg element part begins. If there are no more optics (besides gg), then yes, all you have to do is put a gg in front of it and get a mount.

everyone check out the other thread, its starting to see some more life.
http://www.dvinfo.net/conf/showthread.php?s=&threadid=23451&perpage=15&pagenumber=3
stephen birdsong

I was ordering my gg from optosigma today, and I spoke with an engineer. They do custom manufacturing. Its as simple as that.

He gave me lots of advice on the lens (alot of which I did not understand). And he said that I need to figure out exactly what I need and they would do it.

that was easy.

Of course, I did not get a price, that could be the catch.

He spoke of it as if it were easy, and something he could do in half an hour. (design the lens).

so, back over to the other thread where, hopefully, we can get this ball rolling and figure this out.

stephen

Mike, I'm not really biting into the debate, I just gave advice about the most economical and marketable solutions. If you go to a pricey manufacturer with a low volume market you will get very expensive product, like just for XL users (we are talking thousands of units to start to get economies of scale, hundreds maybe not). You might as well go to an engineering firm with a worked out design for a custom order. If you have high volume, with quality low priced manufacturer, then you can get lower price than going to an engineering firm with small order. My design suggestion allows an manufacturer to target hundreds of thousands of users. The price of adaptors is cents (for casing) to dollers (for mechanical lense control mechanisms) in this sort of volume. The price difference between 35mm and MF focus screen/condensor lenses (furthure relay can be normal size) to their respective manufacturers is going to be dollers as well. But this is only an idealistic suggestion, MF is not really needed for most people). You could specify only the most common lense mountsd (Nikon, Canon, etc). So if you pick the right company they can get the parts cheap, or manufacture them cheaper, but probably not in runs of less than thousands (hundred thousand is even cheaper).

You probably could go to them with a XL1 system , with a backup universal system suggestion if they don't think the XL market is big enough to worry about for less than $5-10K a peice.

Well that's my input, I'm not really interested in it for myself (though maybe a universal one). Just remember when the HD Canon models come out you'll want one for that too (so the best GG would be best to start with, I'm wondering about something simular to the Canon laser bright focusing screens which have 220 million microlenses) . Mike, have you thought of talking with people in the Alda/Agnus threads and Canon forum to gather interest. Like you, the people there have also been talking about ordering batches of custom adaptors in times past. The people there could probably input into a complete design that could be made at an engineering firm?

Wish you luck.


Thanks

Wayne.

Okay, we need to start somewhere and I guess we need to decide where that is.

Are we going to start looking around for someone capable of fabricating an adapter for a relay lens to attach to the XL1s?

This seems to be the place to start for me--- at least I think it is.

Do you think that the P+S relaylens has somekind of a freshnel lens built in?

Just yesterday I was reading through the latest issue of "Outdoor Photographer" and ran across an ad for two new Sigma lenses.

The interesting thing though is that they were designed *specifically* for small format digital SLRs! Isn't this _precisely_ the thing we have been needing? I'm not sure how large the chips in a DSLR are but if they are currently making lenses for the purpose of removing the magnification factor I think they could certainly work something up for 1/3" chips...

This, if I understand the problem correctly, would give us 35mm lenses without the need for GG and loss of light.

<<<-- Originally posted by Aaron Shaw : The interesting thing though is that they were designed *specifically* for small format digital SLRs! -->>>

canon makes these as well they are called "efs" lenses, they basically set the rear element back so its not so close to the chip, reality is i feel its more marketing then anything else, i have seen little difference using these types...

as for lens petition its a good idea, i feel that there is a market for primes with real manual focus controls...with 3 generations of the xl mount out there it should pay off well, if a mini 35 can be made for 10gees by an upstart a tamaron or sigma should be able to build great lenses with there eyes closed...

with all this talk about an open lens system for under 6 grand i still can't put a prime on my camera for under 10grand

Found one of the lenses. Couldn't find the other oddly...

The two new lenses are 18-55mm and 55-200mm giving good coverage of both wide angle and telephoto. Both will cost MSRP $319 USD (together).

http://www.sigma-photo.com/Html/pages/18_50_EX_DC.htm

>>
canon makes these as well they are called "efs" lenses, they basically set the rear element back so its not so close to the chip, reality is i feel its more marketing then anything else, i have seen little difference using these types...<<

Really? That's too bad :(

P+S have no own lens. They use a 25mm high quality c-mount lens from Schneider Kreuznach. This lens is a very fast lens (under 1), so also 16mm filmmakers love this lens since years. Here in germany the lens cost round 900,- euro.

Close behind the GG is a condenser lens. This is because the hotspot, but P+S use NO other lens. With the Schneider lens there is no vignetting in the image and it can focus on short distance. The distance between lens and GG is round 11cm (prisms + mirror = 10cm).

If you wont a bright picture, but without DOF, you can remove the GG (but not the condenser).

This way work a adapter form Angenieux:

http://www.smsprod.com/products/lenses/angenieux4.html

It reduce the image size from 35mm film lenses to a video sensor. But this very expensive part have no prism, so the picture is upside down. Okay this is only for 2/3" sensors, but just have a look inside.

EF-S lenses have the rear element set closer to the chip. This is why they only fit cameras modified to use them. The mirror is made slightly smaller and it swings back and up to avoid hitting the rear element. They have a new 10-22 mm lens coming to market soon. It will have the 35mm equivalent of 72-158 on the XL/1 series and 96-211 mm on the XL2.

<<<-- Originally posted by Jeff Donald : EF-S lenses have the rear element set closer to the chip. -->>>

errr i have that backwards thanks for correcting me ...efs lenses can protrude further in

Wayne.

forgive me, I somehow missed your first post.

I think you have a great idea.
That is definately a shift from what I was thinking, my only concern is if they turn it into a major marketing thing, ps technics will probably crack down and possibly stop production. I believe they have a patend, although I don't know how much their patend covers. Although there is movietube, which is already advertising their product. I don't really know.

If ps technics is charging $10k+, and sigma researches the market, that could seriously hurt our efforts, as they will most likely want to cut ps technics, but not by too much.

Stephen

Rai, are you saying that p+s uses the Angenieux as their relay lens? or are you saying that they use another companies lens as their relay lens, one that we could purchase on our own. If so, that is great news, as the relay lens is where most of us are stuck on our xl1 systems.

stephen

1. We need to figure out what focal length we need for our relay lens.
2. we need to figure out what focal length we need for our condensor lens (hot spot issues).

our options for relay lens are:
a. using a standard 35mm lens with some sort of mount adapter
b. using an achromatic doublet and fashioning our own mount system.


I did some research today. My first concern is to figure out what focal length relay lens we need.

If I had taken a geometry class, I would be able to solve this very easily, so maybe I can get some help.

if we know the angle of view of various focal lengths, and we know approximate distance from film plane, than with the angle of views, we can calculate the focal length.

here is the info I have:
in 35mm fl
14mm-81 degrees
17mm-70 degrees
20mm-61 degrees
24mm-53 degrees
28mm-46 degrees

No it's there, Mike has the first post, I was just adding onto his idea.

There are probably many patents, most defunct, so just aviode the non-defunct ones. PS-Technics can try, but where ever they can suceed is another thing, they need to have the right/right patent, otherwise they can just make life miserable. As I said this is an old subject int he Agnus/Alder threads, they might like to get involved.

stephen, read carefully what rai wrote.
Everything is in the first paragraph: Schneider Kreuznach 25mm f 1:0,95 - the only thing to change is the mount (from c-mount to xl-mount).

dietmar

Look at this

http://de.geocities.com/raiorz/vibro_old/relaislens_1.jpg

My company have made the Canon Lens Adataper.
And also all other parts you need for a 35mm vibration solution. The case is ALU, it have 2 build-in light weight support rods. The vibration drive need 6V DC, but only 35mA

look at this

http://de.geocities.com/raiorz/vibro_old/relaislens_1.jpg

Its only the relaislens, but original the same like P+S.
My company have made the Canon Lens Adataper.
And also all other parts you need for a 35mm vibration solution. The case is ALU, it have 2 build-in light weight support rods. The vibration drive need 6V DC, but only 35mA.
We cant sell the adapter (because P+S patent etc.) but maybe the parts

look at this

http://de.geocities.com/raiorz/vibro_old/relaislens_1.jpg

Its only the relaislens, but original the same like P+S.
My company have made the Canon Lens Adataper.
And also all other parts you need for a 35mm vibration solution. The case is ALU, it have 2 build-in light weight support rods. The vibration drive need 6V DC, but only 35mA.
We cant sell the adapter (patent etc.) but maybe the parts

Rai: why would this have anything to do with the P+S patents?
From the looks of it your adapter has no rotating or vibrating
ground glass?

I just bought a relaylens from P+S for 1090 euro. But it doesn't look exactly like the lens you are showing in the link. The iris ring is closer to the camera than the focus ring. But perhaps they are otherwise identical!

Anders,
what is your plan to mount the lens to your camera?
Im curious to know what you find out from your lens, fill me in.

Stephen

Anders,
Schneider Kreuznach made the inside lenses but the Housing came in differnt design and under differnt names (Angenieux or Schneider Kreuznach or others). But inside it is the same

So basically, if you buy the relay lense from Schneider, you then have to mount your own ground glass in front of it, and somehow connect a mount (PL, Nikon, whatever) to the ground glass.

Look at this

http://de.geocities.com/raiorz/vibro_old/relaislens_1.jpg

My company have made the Canon Lens Adataper.
And also all other parts you need for a 35mm vibration solution. The case is ALU, it have 2 build-in light weight support rods. The vibration drive need 6V DC, but only 35mA

Great. How much does it cost to make? Are you going to distribute plans or are you willing to make more and sell them?

And I'm assuming, the plans.

How much are the parts going to cost?

My estimate: 1100 Euro for the lens and 300 USD for the kit.

I was wondering about the whole prism (rotate image) question. Doesn't the prism and mirror steal F-stops??
Because on the XL-1 you can simply flip the eyepiece to the other side and the image is corrected. Then in post you can just use the:

http://www.leadtools.com/SDK/Multimedia/Direct-Show-Filters/Multimedia-DirectShow-Rotate.htm

during capture (without loss I hope). If this is true then I would rather avoid bothering with prism and mirrors.

Or am I wrong???

We can sell the relay lens for Euro 900,- (round $ 1.115,-)

We found a cheaper one, but i dont know how good it is. We check it next 2 weeks

A mount adapter (to connect the lens to the Canon) cost Euro 198,- ( $ 245,- )

BTW: only with this lens (without the other GG adapter parts) you can make good night shoots. ( F stop = 0,95 )

Anders,
yes, the prism "steal" a little bit light but. In F-stops? I think only 0,05.

The prism is a expensive part, because you need a "big on" with inside more than 40mm diameter and it must be color corrected. I will check out the best price till next week Without the prism you need 10cm more distance.

I don't understand why it needs to have 10 cm more distance!
In a normal still-camera the lens is only about 5 cm from the film... I can see that without the prism and mirror the light will travel a shorter distance but... I'm sure that you are correct but could you explain it to me?

I would properly be interested in buying a colorcorrected prism then - So it would really like to know the best price you find.

In the PDF file showing the PRO35 there is something called "Schutz glas" - Is that a fresnel??

Thanks

schutzglas means protective glas

The way through a prism is longer than the prism outside. A still-camera have also build in a prism. So the way in a still-camera is also more then the outside dimensions.

But in different to the still-camera prism, you need a bigger one, because the relay lens have more than 30mm light circle. Thats why you need the big prism and thats why it take more distance.

Okay, you can mount a macro lens in front of the relaylens to reduce the distance, but than you will have some distortions.

The "SCHUTZ GLAS(S)" is only a clear glass to protect (SCHUTZ=protection) the inside parts for dust and dirt.

To reduce (elimate) the hot spot there is a convex lens with the plan side very near behind the vibration GG (sorry last day i call this condenser, thats wrong)

That's a little over $1700 American. Still, at 1/5 the price of the Mini35, if it works, it wouldn't be too bad an investment.

My biggest problem with the idea of buying the Mini35 (I've rented it, but I really, really don't like renting equipment - I like to own so that I can spread out cost over years and keep individual production costs down) is the idea of putting $10,000 worth of equipment on a $3,000 camera. For that kind of investment, I would just as soon buy a better camera.

You say that the prism is expensive - what are talking here, $100 ? $500??????

I can't help but believe that there has to be a slightly less expensive way to do this--- yeah, 1700 bucks isn't as bad as 5000 but still we are talking about a fairly simple idea here.

I've used the Mini-35 with some pro 35mm lenses myself (had a client pay the tab for renting it) and loved what it gave me and have to believe there is a way to do an Agus35 for under a grand.

Maybe I'm out of touch (which might be so) but I have seen others do them for lesser cameras for next to nothing.

Im with you Kevin.

This lens is not the only way to go.
What it affords us is this:
c-mount (which can be converted to xl mount)
very fast at f.95 (all i can say is, wow)
and wide enough at 25mm to capture 24x18mm frame
moderately small min focus distance

the downside is that it is $1100.

if we can find a lens that isnt quite as fast, but is wider (able to capture the still 35mm frame) and has a mount that can be coverted to xl, then we are in luck.

OR, we can continue to test building from scratch, ie the info I got from the optical engineer at optosigma, using a achromatic doublet as our relay lens (24mm) and a pcx as our condensor, and a gg, with a simple mount in front of the gg. this may be the way to go if cost is an issue.
all of these items are obtainable through optosigma website.

I also found out that you can return optics to optosigma as long as they are in good condition, that way we have the ability to use trial and error.

the gg that you can buy from them is 1500 grade, probably better quality than I can make by myself, it costs $24. All of the other parts are cheap, between $20-50. We could probably get a mount made at a local machine shop using the cap that came with our camera, have it reversed machined or whatever.

The most difficult thing I am foreseeing is constructing a system to make accurate at fine tunings to distances, and having an effective method to measure that data. This could be more difficult to to than the lens itself.

stephen

now you are talking... I would love it if I had the money to drop on a more expensive solution but if that was the case I'd just breakdown and buy a Mini-35 but I doubt that I can talk the wife into selling off a kidney or a second mortgage for that sort of thing.

I seem to see the big problem as being finding a cheap adapter to go from the XL mount to a standard (relay) lens mount.

I don't have the brain cells left to start reading through the several thousand post long Agus35 threads here but when I have I see people will very practical skills at figuring out focal lengths and solutions--- I think we need to invite a few of these brainy folks to advise us on this.

There are plenty of folks out there with XL1, XL1S and XL2's that would be interested in this sort of project--- we just need to get them in here and helping out!

What would be good, is if we could consolidate the xl1 35mm adapter threads. As of today, there are 3 active ones.

wonder if a moderator could merge them. There simply isnt enough resources to split up our efforts.

I cant order them right now, I may have to wait a week or so, but here are the lenses needed in case someone else wants to start:
relay lens (achromatic doublets) 20mm and 25mm
http://www.optosigma.com/miva/merchant.mv?Screen=PROD&Store_Code=OS&Product_Code=pg49-52&Category_Code=Achromatic+Doublets

condensor lens need to figure out what focal length
http://www.optosigma.com/miva/merchant.mv?Screen=PROD&Store_Code=OS&Product_Code=pg55-61&Category_Code=Spherical+Lenses

ground glass 50mm diameter (1500 grade)
http://www.optosigma.com/miva/merchant.mv?Screen=PROD&Store_Code=OS&Product_Code=pg211&Category_Code=Filters+%26+Apertures

prime lens mount and housing is something we need to figure out how to do, as pvc is somewhat limited in its adjustability.

I encourage everyone to try and participate in this process and not just wait for me to succeed. Achieving a solution will be much quicker that way.

stephen birdsong

Okay... here's the deal. I'm starting a "Consolidated XL1 35mm Adapter Thread".

I would ask that folks here copy over the relevant posts (with the name of who posted them originally) and we can get things rolling along in one single thread.

Since we've got three different threads covering the XL1 and creating an adapter for it we decided we wanted to move it all over into one.

At this point (I believe) the place to start off is with an adapter for a relay lens to the XL mount.

I ask everyone copy over any relevant posts into this thread so we can keep rolling on this and make some progress.

Hi.

Since we've got like 3 or 4 threads going on the XL1 adapter issue and I think things are starting to move forward toward an organized option I'm starting a "Consolidated XL1 35mm Adapter Thread".

I would ask that folks copy over the relevant posts (with the name of who posted them originally) from the assorted threads and we can get things rolling along in one single thread.

here's a couple of the recent posts from Stephen Birdsong:

-----
1. We need to figure out what focal length we need for our relay lens.
2. we need to figure out what focal length we need for our condensor lens (hot spot issues).

our options for relay lens are:
a. using a standard 35mm lens with some sort of mount adapter
b. using an achromatic doublet and fashioning our own mount system.


I did some research today. My first concern is to figure out what focal length relay lens we need.

If I had taken a geometry class, I would be able to solve this very easily, so maybe I can get some help.

if we know the angle of view of various focal lengths, and we know approximate distance from film plane, than with the angle of views, we can calculate the focal length.

here is the info I have:
in 35mm fl
14mm-81 degrees
17mm-70 degrees
20mm-61 degrees
24mm-53 degrees
28mm-46 degrees
----------------------------------

if we can find a lens that isnt quite as fast, but is wider (able to capture the still 35mm frame) and has a mount that can be coverted to xl, then we are in luck.

OR, we can continue to test building from scratch, ie the info I got from the optical engineer at optosigma, using a achromatic doublet as our relay lens (24mm) and a pcx as our condensor, and a gg, with a simple mount in front of the gg. this may be the way to go if cost is an issue.
all of these items are obtainable through optosigma website.

I also found out that you can return optics to optosigma as long as they are in good condition, that way we have the ability to use trial and error.

the gg that you can buy from them is 1500 grade, probably better quality than I can make by myself, it costs $24. All of the other parts are cheap, between $20-50. We could probably get a mount made at a local machine shop using the cap that came with our camera, have it reversed machined or whatever.

The most difficult thing I am foreseeing is constructing a system to make accurate at fine tunings to distances, and having an effective method to measure that data. This could be more difficult to to than the lens itself.

----------------------

What would be good, is if we could consolidate the xl1 35mm adapter threads. As of today, there are 3 active ones.

wonder if a moderator could merge them. There simply isnt enough resources to split up our efforts.

I cant order them right now, I may have to wait a week or so, but here are the lenses needed in case someone else wants to start:
relay lens (achromatic doublets) 20mm and 25mm
http://www.optosigma.com/miva/merchant.mv?Screen=PROD&Store_Code=OS&Product_Code=pg49-52&Category_Code=Achromatic+Doublets[/url

condensor lens need to figure out what focal length
[url]http://www.optosigma.com/miva/merchant.mv?Screen=PROD&Store_Code=OS&Product_Code=pg55-61&Category_Code=Spherical+Lenses

ground glass 50mm diameter (1500 grade)
http://www.optosigma.com/miva/merchant.mv?Screen=PROD&Store_Code=OS&Product_Code=pg211&Category_Code=Filters+%26+Apertures

prime lens mount and housing is something we need to figure out how to do, as pvc is somewhat limited in its adjustability.

I encourage everyone to try and participate in this process and not just wait for me to succeed. Achieving a solution will be much quicker that way.

it would probably be better to have a moderator do it.

stephen

So bear with this question for a second:

Can some one tell me the benifit of the Mini 35 adaptor, Canon's or otherwise?

What would I want to use it for?

Flexibility with DOF or depth of field. One of the most noticable characteristics of dv that sets it apart from 35mm is its enourmous dof.

A good starting point might be getting your hands on an adapter that JVC used to make. It adapted Nikor lenses to 2/3 inch bayonet for video cameras. This was just a relay lens adapter and there was no magnification of focal lengths. You could possibly reverse engineer the adapter for use with the XL mount.

jeff, could you be more specific on how this would be of help?
whether there are optics in the adapter or not, a larger format lens will always produce what is arguably called a multiplier effect. Not sure of the acurate way to say it, but a 10mm 2/3 in will act like a longer 1/3 inch.


stephen