Jump to content


Photo

switar rx lenses for super16


  • Please log in to reply
18 replies to this topic

#1 adam berk

adam berk
  • Sustaining Members
  • 168 posts
  • Director

Posted 16 December 2006 - 08:13 PM

Does anyone know of, or could anyone quickly type out a list of the switar rx lenses that are OK for super16?
  • 0

#2 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 16 December 2006 - 09:07 PM

all but the 10mm - both standard and preset, although the preset is slightly better so I've heard
  • 0

#3 Jeremy Rumas

Jeremy Rumas
  • Basic Members
  • PipPip
  • 95 posts
  • Other
  • USA

Posted 17 December 2006 - 05:31 PM

all but the 10mm - both standard and preset, although the preset is slightly better so I've heard


What will the results look like if shooting S16 with the 10mm switar? I was hoping to use this lens once I get my Bolex converted to S16.

Also, what do you mean by standard and preset?

thanks,

Jeremy Rumas
  • 0

#4 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 17 December 2006 - 07:02 PM

What will the results look like if shooting S16 with the 10mm switar? I was hoping to use this lens once I get my Bolex converted to S16.

Also, what do you mean by standard and preset?


There are two 10mm Switar lenses made for the reflex cameras - the older one, and the newer one - the newer one has little aperture preset arms and is made to connect with the 5.5mm aspheron attachment also.

If your lens looks like a lens then you have an older one, if your lens looks like a lens but with sticky-outy bits then its a preset 10mm

The preset arms make it easier when focusing and composing the shot when using small apertures but it does not alter the lens quality, however the optics on the preset lenses are better anyway (they had more time to think about it I suppose)

As for what your vignetting will look like see this:

its a short I found linked in another forum - shot on a bolex, although at youtube they say the vignetting was caused by the 'wide' 26mm but I think they are incorrect - I have had experience with both lenses, the 26mm does not vignette and the 10mm vignettes just like that seen in the film. Prob just got their wires crossed.

With the 10mm on super16 it is often zoomed in slightly in telecine, effectively turning it into a 12mm or so - still both great lenses, you'll pay a premium for the presets though...
  • 0

#5 Sir Alvin Ekarma

Sir Alvin Ekarma
  • Basic Members
  • PipPipPip
  • 209 posts
  • Director

Posted 18 December 2006 - 12:21 AM

According to JK camera www.jkcamera.com , a RX-collimated 12.5 Computar CCTV lens is not only S16 safe but comparable to a switar. In my own tests, the lens looks good but I didn't have a 10mm switar to compare it to.
  • 0

#6 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 18 December 2006 - 01:36 AM

but its a 12.5mm not a 10mm so the comparison is like apples and pears (that have a hint of apple in them) -

You can get the CCTV lenses for under $100 new on eBay a new Switar 10mm will cost $2000 - it will focus down to 8" but the price difference is extreme so somethings gotta give - either the computars are crappy (I would suggest especially when shooting open) or the Switar is waaaay over priced (like every other piece of film industry IP that turned into a product)
  • 0

#7 Sir Alvin Ekarma

Sir Alvin Ekarma
  • Basic Members
  • PipPipPip
  • 209 posts
  • Director

Posted 18 December 2006 - 03:46 AM

You can get the CCTV lenses for under $100 new on eBay a new Switar 10mm will cost $2000 - it will focus down to 8" but the price difference is extreme so somethings gotta give - either the computars are crappy (I would suggest especially when shooting open) or the Switar is waaaay over priced (like every other piece of film industry IP that turned into a product)


Wide open, the computar didn't look so hot but okay-- about as well at wide open as the 25mm switar I was testing it against; still, it's not like I'll be shooting by candle light any time soon. At f4, the image quality was comparable for both lenses. Surprisingly the lenses that totally crapped out wide open in my tests were a 15mm angenieux and 50mm takumar SLR lens.
  • 0

#8 adam berk

adam berk
  • Sustaining Members
  • 168 posts
  • Director

Posted 18 December 2006 - 04:03 AM

so the 25mm switar 1.8 doesn't look so hot wide open? I just snagged myself a great deal on one. Should have it next week. I am trying to stick with nikon's in addition to the 16mm switar I have. I figured a 25mm switar would be a good stepping stone between the 16mm switar, and my 50mm equivalent nikon.

Wide open, the computar didn't look so hot but okay-- about as well at wide open as the 25mm switar I was testing it against; still, it's not like I'll be shooting by candle light any time soon. At f4, the image quality was comparable for both lenses. Surprisingly the lenses that totally crapped out wide open in my tests were a 15mm angenieux and 50mm takumar SLR lens.


  • 0

#9 John Film Runner Smith

John Film Runner Smith
  • Guests

Posted 18 December 2006 - 11:52 AM

According to JK camera www.jkcamera.com , a RX-collimated 12.5 Computar CCTV lens is not only S16 safe but comparable to a switar. In my own tests, the lens looks good but I didn't have a 10mm switar to compare it to.


The Switar 10mm (f1.6) covers Super 16 as long as your lens mount is re-centered.

You don't even need to collimate the Computar. Your focus marks shift ever so slightly on a REX. But you need to have the proper model number Computar, problem is it doesn't say the model number on the lens.

I will try and find the model number and post it here.

High end lens dealers won't want to hear this, but the proper model number 12.5mm Computar outperforms most lenses costing ten times as much.

But, again, the Switar 1.6 10mm WILL fully cover Super 16mm as long as your lens mount is re-centered.

F.R.
p.s. and the 12.5mm computar has so much coverage it will FULLY cover the Super 16mm aperture even if you didn't re-center the mount! A great lens.
  • 0

#10 Sam Wells

Sam Wells
  • Basic Members
  • PipPipPipPip
  • 1751 posts
  • Cinematographer

Posted 18 December 2006 - 01:02 PM

It's not only a question of collimation with a wide angle lens wide open on an RX, it's correction for spherical aberration (which can look beging in some cases) and astigmatism.

A test I would try with the Computar is this -- shoot a face in MCU with sharp objects (chart etc) immediately in front of and behind the subject. Does the face look soft in relation ?

Question for Nick M - WAS your lens recentered ?

-Sam
  • 0

#11 Sir Alvin Ekarma

Sir Alvin Ekarma
  • Basic Members
  • PipPipPip
  • 209 posts
  • Director

Posted 18 December 2006 - 01:15 PM

so the 25mm switar 1.8 doesn't look so hot wide open?


I lit it for around f1.4 using 7212, and the image held together. Still, it didn't want to make me shoot everything with a single 250w photoflood.


A test I would try with the Computar is this -- shoot a face in MCU with sharp objects (chart etc) immediately in front of and behind the subject. Does the face look soft in relation ?


I did this in one of my tests: one test was a long shot, the other a MCU, both times with shots at f4, f2.8 and wide open. As I mentioned, it held up well against my 25mm switar and Switar zoom in image quality but I regret not being able to to test it against a 10mm switar. Surprisingly , the lens that had the best image (at f4 and f2.8) was the Angenieux-- not devastaingly slow, but noticeably.
  • 0

#12 adam berk

adam berk
  • Sustaining Members
  • 168 posts
  • Director

Posted 18 December 2006 - 03:07 PM

I lit it for around f1.4 using 7212, and the image held together. Still, it didn't want to make me shoot everything with a single 250w photoflood.
I did this in one of my tests: one test was a long shot, the other a MCU, both times with shots at f4, f2.8 and wide open. As I mentioned, it held up well against my 25mm switar and Switar zoom in image quality but I regret not being able to to test it against a 10mm switar. Surprisingly , the lens that had the best image (at f4 and f2.8) was the Angenieux-- not devastaingly slow, but noticeably.



just went ahead and bought one of these computar's for $14 on ebay. This should be interesting. I'm just hoping I got the right one... ha :P
  • 0

#13 John Film Runner Smith

John Film Runner Smith
  • Guests

Posted 18 December 2006 - 03:58 PM

It's not only a question of collimation with a wide angle lens wide open on an RX, it's correction for spherical aberration (which can look beging in some cases) and astigmatism.


That is utter marketing brainwashing horse manure to get people to buy RX lenses.

RX lenses do not correct for astigmatism. That is impossible unless you have a way to lock the lens in place like the frames of a pair of glasses do on a persons head.

You put a c-mount lens on your REX, your focus marks shift slightly. That's it.

F.R.
  • 0

#14 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 18 December 2006 - 05:07 PM

It's not only a question of collimation with a wide angle lens wide open on an RX, it's correction for spherical aberration (which can look beging in some cases) and astigmatism.

A test I would try with the Computar is this -- shoot a face in MCU with sharp objects (chart etc) immediately in front of and behind the subject. Does the face look soft in relation ?

Question for Nick M - WAS your lens recentered ?

-Sam


Its not my gear, but I have experience with it ... (I personally own the same stuff but its not super16 yet)

The conversion in question was done at Bolex - you can choose between normal or super16 by loosening the prism/bayonet housing and moving it left or right... if its set at normal you get heavy vignetting on one side anyway

It can be clearly seen in telecine where its easy to pull out and see the full frame, slightly less so in projection (reg16 projection looking at one side) - but still there nevertheless

So you have a 10mm with no vignetting ? what SN, details ... etc... maybe there is a range that has the coverage, would love to find out

Has anyone looked at that youtube video I linked ? Its the perfect example of vignetting with a 10mm that I'm talking about...

Edited by Nick Mulder, 18 December 2006 - 05:08 PM.

  • 0

#15 Sir Alvin Ekarma

Sir Alvin Ekarma
  • Basic Members
  • PipPipPip
  • 209 posts
  • Director

Posted 18 December 2006 - 05:23 PM

just went ahead and bought one of these computar's for $14 on ebay. This should be interesting. I'm just hoping I got the right one... ha :P


They're pretty much all the same; you can basically tell by the picture-- if the c-mount thread has some odd looking lens elements that really shoot out, you don't want it. What gets me is that there's some guy who sells them like they're some kinda super secret gadget and he'll shot by the mafia if he gives the brand name.

Re: collimating for RX. Yeah, you can focus by eye and even Chambless told me that focusing on the ground glass will take care of most of your worries, but.... better safe than sorry. Dieter at Procam can do it for a decent price.

Edited by Sir Alvin Ecarma, 18 December 2006 - 05:26 PM.

  • 0

#16 Sam Wells

Sam Wells
  • Basic Members
  • PipPipPipPip
  • 1751 posts
  • Cinematographer

Posted 18 December 2006 - 08:40 PM

You put a c-mount lens on your REX, your focus marks shift slightly. That's it.

F.R.


I'm not going to argue with you; I've read Dennis Couzin's paper on this and actual use of RX and non RX lenses on Bolex cameras would tend to confirm what he says.

-Sam


So you have a 10mm with no vignetting ? what SN, details ... etc... maybe there is a range that has the coverage, would love to find out


No I haven't done the conversion yet.

I'd like to hear from someone who can confirm they've used a 10mm Switar and fully covered the S16 frame' so far I haven't

-Sam
  • 0

#17 Jeremy Rumas

Jeremy Rumas
  • Basic Members
  • PipPip
  • 95 posts
  • Other
  • USA

Posted 18 December 2006 - 08:45 PM

Has anyone looked at that youtube video I linked ? Its the perfect example of vignetting with a 10mm that I'm talking about...


Checked it out. Really beautiful footage, though I don't want vignetting like that. That does look a lot more like the 10mm than the 25mm throughout. As the vignetting is equal on each corner, it would seem the lens mount was recentered on his Bolex. Thanks for all the info.

As a sidenote, at the right of the frame there were quite a few places in the footage where there was a red blow out. Is this from a light leak into the daylight spools while loading/unloading most likely? I've yet to shoot S16, but keep reading about how loading in daylight is so much more critical with S16 as opposed to R16.

Jeremy Rumas
  • 0

#18 Nick Mulder

Nick Mulder
  • Basic Members
  • PipPipPipPip
  • 1023 posts
  • Other
  • Auckland, New Zealand

Posted 18 December 2006 - 08:48 PM

its getting off topic here with collamating RX/non-RX issues getting involved - perhaps that discussion could be had in the other thread just started up...

In the meantime I'd still like anyone interested to take a look at this:



Its not too bad, shot on a Bolex and has vignetting in the wide shots just like what I've seen with the 10mm Switars... it isnt so apparent through the viewfinder, but as I've said one you are in a telecine suite and can zoom out to see the full frame there it is ...
  • 0

#19 Sam Wells

Sam Wells
  • Basic Members
  • PipPipPipPip
  • 1751 posts
  • Cinematographer

Posted 18 December 2006 - 08:58 PM

RX lenses do not correct for astigmatism. That is impossible unless you have a way to lock the lens in place like the frames of a pair of glasses do on a persons head.


Astigmatism as defined as a lens aberration refers to inabilty to simultaneously focus radial and axial rays so I don't think correcting for it requires the lens to be "locked" in any position.

-Sam
  • 0


Paralinx LLC

Media Blackout - Custom Cables and AKS

CineLab

Rig Wheels Passport

Technodolly

rebotnix Technologies

Metropolis Post

Glidecam

Ritter Battery

Tai Audio

Visual Products

CineTape

Broadcast Solutions Inc

Willys Widgets

FJS International, LLC

Aerial Filmworks

Opal

Wooden Camera

The Slider

Gamma Ray Digital Inc

Abel Cine

Gamma Ray Digital Inc

Opal

Metropolis Post

Broadcast Solutions Inc

Abel Cine

Visual Products

Rig Wheels Passport

Tai Audio

rebotnix Technologies

Technodolly

CineTape

CineLab

The Slider

FJS International, LLC

Ritter Battery

Willys Widgets

Media Blackout - Custom Cables and AKS

Aerial Filmworks

Wooden Camera

Paralinx LLC

Glidecam