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-   -   Lenses for SI-2K (https://www.dvinfo.net/forum/silicon-imaging-si-2k/317065-lenses-si-2k.html)

Alex Raskin August 24th, 2009 12:56 PM

Lenses for SI-2K
 
Wouldn't it be great to have a thread here that summarized practical experiences with lenses for SI-2K - what do you think?

With the conflicting info floating out there, lens acquisition becomes a costly adventure. Anything that sheds more light on the subject would be useful, IMHO. For instance, two Kern Switar lenses, 10mm and 16mm, that are described as covering the S16 sensor, in fact were not in my experience, and vignetted instead.

Here's the good news: just discovered a never-before mentioned machine vision lens 2/3" Tamron 8mm wide-angle. It appears to be sharp, fast at f1.4, and it covers the entire SI-2K sensor in my tests. Cheap, too!

Tamron | 23FM08-L 2/3 8mm F/1.4 High Resoluti | 23FM08L | B&H

Maybe you could also share your own practical experiences and recommendations re, lens choices for SI-2K.

Alex Raskin August 27th, 2009 09:08 AM

I still don't understand the issue completely, so it'd be great to collaborate with people who have practical experience with SI-2K cam and different lenses.

Here's what I have figured so far (please feel free to point out my errors, which I'm sure are there):

- Machine vision lenses produce cold, unpleasant image. Focus is hard to pull because the DOF is razor thin. On the flip side, they are cheap (around $300 new), very fast (1.4 no prob), and easy to get. Example: Fujinon machine vision

- Manual SLR 35mm lenses - mixed bag, depends on the lens. I like Zeiss - super clear but pleasant image, easy to get (but not wide angle ones.) I have and love 50mm and 100mm Planar's, F mounted. Also have some great Nikon lenses. Use them with an F to C mount adapter. C-mount plate sits on my SI-2K permanently now.

- Old Super16mm cine lenses, like Kern Switar. Very moody, wide angled ones do produce vignetting in my case, BUT I love their creamy, 3D-like, contrasty image of the closeups. Not much luck with focusing on infinity in some cases. Very small and lightweight, yet great image quality. Pricing on eBasy seems around $200 - $500 depending on condition, and up to $1,300 for certain models like Switar 26mm 1.1

Now, if you go that route like I did, and collect different type lenses to cover the range of prime focal lengths, then you end up with a bunch of all different sizes and mounts. Makes it virtuially impossible to effectively use follow focus when you need to change lenses a lot.

So the next step is to buy a set.

Then all lenses are matching optically and mechanically, including FF gear on front elements. No more swapping adapters for rear elements, either.

But: Sets are expensive. Optar Illuminas seem to go for $14,500 for a set of 6 new. Used Zeiss Superspeeds seem to go for $17,000 for 4 - 5 lenses.

So here goes my question. If you actually tried Illuminas and Zeiss lenses on SI-2K... what was your impression - are they optically so much different (better, sharper) than say SLR Nikon/Zeiss glass, or than little Switars?

Or are they optically so close to the cheaper ones that you can't discern much optical difference, but the set gives you that "professional" look and a convenient, unified way to mount and control all lenses?

Lior Molcho August 27th, 2009 04:39 PM

Hi Alex

I own a small set of zeiss super speeds purchased at Alan Gordon's in LA 9.5,16,25mm
having compared them to about 10-12 different misc sets of 35mm lenses:
Digiprimes, old primes and optars they held up very well in resolution tests, color unity and operation
mind you, a digiprime on a dedicated 35mm sensor\gate will (almost always) be much sharper than on the mini, but compared to the s16mm lenses on the mini, the difference is hard to find, and in some sets, the 16mm seiss even top 35mm sets that are considered very expensive

As much as I understand your "quest" for reports on lens behavior,and which one is "best" in the end I feel that it really depends on the eye of the beholder and what's practical for you to use in terms of geography and budget
personally I wouldnt mind lenses that were even softer, or would flare more , so it really is a question of how to use each lens's qualities to the best of your project

my two cents

Lior

Alex Raskin August 27th, 2009 04:54 PM

Lior, you seem to imply that Optar Illuminas stand higher quality-wise than your Zeiss Superspeeds, so you were a bit surprised to see that your Zeiss lenses stood their own comparing to Illuminas.

Did I get it right?

Which Superspeeds did you get - MK II?

Bob Hart August 28th, 2009 01:55 AM

The two SI2K cameras here in Western Australia use the same lenses in two sets as 3D is in the pipeline in the near future.


Lenses are :-


Cinema Products ( made by KOWA ) Ultra T*

9mm T1.35.
12.5mm T1.25.
16mm T1.25.
26mm T1.25.


Angenieux :-

17.5mm - 70mm T2.5 "Compact" zoom.


Subjectively, the last stop on the Ultra T* lenses seems to be a bit flary and maybe a little softer.

Notes on the web suggest they are as sharp at tighter apertures but warmer in colour than Zeiss which seem to have a cool modern look.

The 9mm has to be modified for Super16mm or SI2K coverage. This mod consists of four reliefs cut out of the front element retention ring on front of the lens where the ring itself introduces a vignette.


OTHER LENSES.

Other lenses used which seem as standout sharp as the Zeiss and Ultra T* have been Nikon (Noct Nikkor) 58mm f1.2, (an expensive lens no longer made), Nikon 28mm f1.4 (an expensive lens no longer made), Micro-Nikkor 55mm f3.5, which also focuses very close.


Two old Cooke (Taylor, Taylor and Hobson) Speed Panchro Series II 35mm cine primes of 50mm T2 and 70mm T2 come up very nearly as sharp as the Nikons. Mint specimens may be better. The ones I have played with are well used and were fungussed before I took them apart. Both have 12-blade irises which yield a nice round softfocus area on soft background pinpoint highlights.

A Schneider-Kreuznach 28mm T2 35mm cine lens also comes up quite sharp. This specimen had a jammed iris and fungus before I tried it. The iris I was able to restore however the original fault remained and one special blade subsequently fractured along a crease line which I had straightened when the fault - a missing mechanical end-stop recurred in use.


Kinoptik made a 9.8mm f1.8 35mm cine prime in ARRI standard mount. This lens will not focus on infinity with the SI2K unless a custom PL adaptor is created with about 0.7mm skimmed off the front face. This lens is not as sharp as any of the Ultra T*, Zeiss or better Nikon prime lenses.

The same lens was rebarrelled by Century with geared focus and given a PL-Mount. This is collimated to a 35mm cine camera and will be too far forward for the SI2K for infinity focus without a custom IMS to PL-Mount adaptor.


Kinoptik made a 5.7mm f1.8 standard 16mm prime in various mounts, C-Mount, ARRI standard mount and Cameflex seem to the the common ones.

This lens will cover Super16mm and the SI2K sensor at 2048 x 1152. It is a little softer than the Ultra T* lenses, the better Nikons and Zeiss lenses but is about as wide a view as you will get short of a fisheye.


In C-mount form, the one I use required the flange of the mount to be rearwards about 1.7mm compared to the normal C-Mount. I caveat this comment in that I don't know whether the C-Mount specimen I have was collimated for Bolex H16RX5 or not. There is a difference.


An old Angenieux 25mm - 250mm T2.3 zoom 35mm cine lens, yields a nice contrast and colour however it is quite soft and I would not by one to use on the SI2K. It was regarded as questionable even on 35mm cameras. A later version apparently was sharper.


Pan Cinor Som-Berthoit 17mm - 85mm T Zoom. C-Mount version.

As an old lens and a zoom, this lens surprised me with its sharpness, nearly almost as good at the Ultra T* primes when they are wide-open. It covers Super16mm and the SI2K for a useful portion of the zoom range, however, this lens suffers from a distinct corner brightness falloff which goes away at about f4. It has a prism split to an optical sidefinder.

It will mount up only to the Mini head separated from the recorder unit with the sidefinder in place. If the sidefinder is removed , the optical port must be covered to prevent a light leak back into the lens.

It needs to have additional support as the C-mount will turn in back of the lens. I would not go out of my way to buy one however if already in possession of one, it may be a handy option for operating the Mini head bare without the OLED electronic viewfinder.

Bob Hart August 30th, 2009 11:27 AM

4 Attachment(s)
Here are some images from the 50mm Cooke Speed Panchro Series II lens. This is a 35mm film camera lens originally part of an ARRI 35mm kit. The owner had bought in Zeiss Ultras and the Cookes were retired into storage.

Frame 4 is a res chart with the Pan Cinor Som-Berthiot 17mm-85mm zoom which is a standard 16mm lens, not Super16mm. There is a it of softness at the edges of the 2/3" frame and pincushion distortion evident but apparent centre resolution seems quite good.

Alex Raskin August 30th, 2009 11:36 AM

Thanks Bob!

Cooke lenses are very expensive though...

I'm trying to, mostly, line up my Kern Switars, S16mm movie lenses, at the moment. Phenomenal contrast/colors, and look pretty sharp to me. Super tiny, they weigh nothing. Downside: how do you pull focus with them?.. Another downside: of course now everyone is after those lenses (+ adapter) because of Pana G1/GH1, driving prices super high all over sudden >:|

Bob Hart August 30th, 2009 11:44 AM

Alex.

These are old Cookes by Taylor, Taylor and Hobson and 35mm purposed lenses not 16mm. I think I saw one on that famous auction site at about $600.00. They are small in size and do not appear to be coated or if so, the coating is uncoloured. The fungus cleaned straight off the glass. The owner, a DP, suggests they are more flary than modern lenses.

Ken at Whitehouse AV suggests that the Kern Switars are good lenses.

Lior Molcho August 31st, 2009 11:15 AM

hey Alex

Never meant 'optar' were or are supposed to be better than 'zeiss'. far from it.
just wanted to illustrate that we checked quite a few sets, and that optar were amongst them.
But once again, were mostly talking about used /refurbished equipment right?
if so then it really comes down to specific lenses , each with its own "history"

really, you should just set up a proper comparison test at your chosen seller's and gauge how well the set that is in your price range looks compared to the seller's best , most expensive set possible

looking at someone else's rez charts or opinion on his specific used/refurbished set might mislead you

best of luck
Lior

Alex Raskin August 31st, 2009 12:22 PM

Thanks Lior, I'd gladly do this but no such opportunity yet to compare the sets.

So I'm trying to pick up as much sensible/useful info based on other people's experiences as possible at this time...

Many thanks for yours!

Bob Hart August 31st, 2009 08:41 PM

I would have to concur with Lior. You can only yourself be your own keeper.

It is difficult however if you are isolated from access to product. You can end up buying and reselling a lot of stuff before you end up with anything near a colour matched lens set.

There are other practical issues. The CP Ultra T* for example. The rear elements are vulnerable. The lens body is quite heavy. When easing out of a PL-mount in particular, they can drop suddenly before you can react and the rear element will clash on the PL rim. Sooner or later there must be a chip.

Because they are quite scarce now, all of a sudden you no longer have a matched set when that happens. Ken Whitehouse is seriously examining the cost of a manufacturing run of replacement rear elements for these lenses so there must a be a few damaged ones around.

Your decision might also depend on how replaceable a lens is and to choose from the most common.

Justin Lovell September 3rd, 2009 10:09 AM

For Documentary work where switching prime lenses is too time consuming (especially considering the dust on the sensor factor) I use my Switar POE 16-100, t-1.9. Very fast, and sharp all the way through. I do love this lens.

Justin
FrameDiscreet.com transfers // cinematography

Alex Raskin September 3rd, 2009 10:46 AM

Justin, these POE zooms - I could only find one with bayonet mount...

How do you mount yours on the Mini? Where did you get your zoom from?

Thanks!

Justin Lovell September 3rd, 2009 11:50 PM

frame discreet lenses
 
Try with:
jean-louis seguin <seguin@alcor.concordia.ca>
Works out of Montreal at Concordia University.

I had my bolex modified to Super 16 with him, he is fantastic. He also had a wide selection of C-Mount lenses...

Justin lovell
Frame Discreet - regular 8mm, super 16mm, super 8mm, film transfers to dvd toronto


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