CP ULTRA T* ( BY KOWA ) SWEET SPOTS.

[Robert Hart]

For interest of anyone shooting an approx Super16mm sized frame, I was moved to recheck a set of CP Ultras for backfocus after one was found to be noticeably sharp compared to the rest of the set. Using the numbers on the SI2K camera, I thought I would also see where the best sharpness for iris settings fell.


The 9mm T1.35 peaks at T3. It is the sharpest lens. Unmodified, this lens will crop the corners of a Super16mm frame. The mod is fairly simple, dressing out the front element retention ring.
The 12.5mm T1.25 peaks at about T3.8.
The 16mm T1.25 peaks at about T3.5.
The 25mm T1.25 peaks T4.

The Angenieux "Compact" zoom 17.5mm - 70mm T2.5 peaks at T4.

A Century-Kinoptik 9.8mm T2 peaks at T5.6.


These lenses are 16mm film lenses and not intended to cover a 35mm film frame.

 

[Albert Schrijvers]

Hello Robert,

How do you think these lenses compare to the equivalent Zeiss superspeeds?

 

[Robert Hart]

Hello Albert.


I am not able to offer a personal comparison of both lens systems however a thread on cinematographer com a while back suggested that the CP Ultra T* family are a warmer colour cast than the Superspeeds which apparently have more of a blueist modern look. The Superspeeds are apparently sharper.

The reviewer ranked the Optar Illuminas next down on the list from the Superspeeds with CPs coming up next.

Varying across the CP lenses, their last half to 1.5 stops to wide open yield loss of sharpness and flare.

The CP 9mm is a magical lens compared with the other CPs. The apparent sharpness is superior and this has been also mentioned by reviewers. It has been suggested the 9mm and 12.5mm vignette Super16mm. The 9mm will but the 12.5mm does not. The 9mm can be modified by dressing the front element retention ring to relief out the corner vignettes. Ken Hale at Whitehouse AV or Visual Products should be able to it for you. Ken Hale definitely can as he did mine.

The focus movement on the CP Ultras "walks" slightly in a consistant spiral movement as focus is pulled. This is more apparent on some lenses than others. I don't think they are ideal for focus pulls in 3D. The pattern of the "walk" may be identical on identically collimated and mounted lenses but I would not count on it.

The 9mm apparently has a hybrid helicoid and cam actuation of the focus movements. There is an observable "bounce" as the cam actuation initiates and a slight change of speed of focus pull.

The CP Ultra focus moves the whole assembly barrel of elements physically forward and back and the lens body extends. There is no apparent breathing. The lens barrel does not rotate.

The rear elements of all the CP Ultra T* lenses are open to injury and this is the typical cause of their demise. I plan to turn some cylindrical extensions out of delrin to protect mine, as shutter mirror clearance is no longer an issue with most digital cinema cams. Ken Hale at one point was apparently contemplating having a production run of rear elements done but this may not be commercially viable. I have not heard any more on the subject.

The CP Ultra T*s are most commonly found in ARRI standard mount or CP-Mount which is a three sector bayonet mount similar to AATON. The ARRI versions can be conveniently mounted to modern PL Mounts with an adaptor. Ken Hale can change the ARRI Standard mounted or CP-Mounted Ultra T*s to a geniune correctly collimated PL-Mount. I imagine Visual Products can do the same.

The CP Ultra T* 16mm on the SI2K appears to interact optically with the sensor face of the SI2K to generate a faint internal reflection artifact. It is a very faint grey if visible at all. It does not seem to move with camera moves. It appears to be there when the full dynamic range of the SI2K image is used.

The CP lenses came with a screw-in metal cap. The thread become gritty and tight unless appropriate standards of camera hygeine are maintained. Except for the 9mm, the filter diameters are 52mm and the filter threads are standard pitch.


These comments are based on my observations of the lenses on CP16 film and SI2K digital cinema camera. The pixel count for 2K on the SI2K is 2048 x 1152. I understand the pixel size is 5 microns. How that compares with the RED/EPIC/SCARLETT windowed down to 2K, I do not know.

The 9mm and 12.5mm are apparently harder to find than the 16mm and 25mm. When I bought the 9mm from Ken Hale, it was then his last in stock but that was three years ago.

 

[Albert Schrijvers]

Hello Robert,
This is very interesting information.
I can only say what my personal experience is with my lenses. I own a 9mm CP Ultra T and a 12mm Zeiss superspeed. This experience is based on viewing 16mm prints, because this is how I work (I don’t have a digital camera).

I must say the 9mm CP never let me down when it comes to image quality. I use it all the time, and 50% of the time wide open. I never found that the image quality was significantly degraded when using it wide open. Also I found that it flares a little less wide open than the superspeed. Even using it at f stop 22 (the Zeiss goes to f11?) didn’t visibly degrade the image: beautiful of contrast, color and sharpness. The color rendition is very, very close to the Zeiss, the whites as well. (I own a Cooke zoom 9-50mm as well: its whites are much "warmer"). The contrast is also very close to the Zeiss.

I found that the superspeed showed significant darkening of the corners used at f stops smaller than f 5.6. That is: at viewed at the fiber screen of my camera. That is the reason that I never used the Zeiss at small f stops, although this effect could also be an artifact of the viewfinder of my camera? The Zeiss is crazy sharp at f 4. I think that the superspeed are optimized for using at stops from T 2 to T 4. The CP’s maximum sharpness could be lower, but to my experience is that the lens is usable over a very wide range of f stops.
Of course viewing a print is something quite different than testing a lens on a bench.

My last questions to you Robert would be: why did you choose to by an 9mm CP form Whitehouse, when you could by a (second hand) 9,5mm superspeed for half the price?

 

[Robert Hart]

Why did I choose a CP lens. Initially it was because I was still deluding myself I could afford to keep running my CP16R camera and the lens mounts were compatable. I had used C-Mount primes on an old Bolex and missed that bit of extra clarity primes give.

The affordability of prime lenses was coming within my range and my personal preference is to use prime lenses. The Angenieux zoom had come with the camera.

The only primes I had for the CP had been 35mm stills Nikons via the CP-Nikon adaptor. I had initially bought a 25mm and 12.5mm off eBay, was muchly impressed with them and had also moved to the SI2K digital cinema camera. The 25mm had a backfocus issue which I only recently resolved. It had been tampered with as it turned out. Another SI2K owner-operator joined forces to provide a 3D camera pair. I enquired with Ken Hale. He had a complete second set in pristine condition he let me have for a good deal along with fitted and collimated PL-Mounts.

Ken sent me the original CP-Mounts so that I could refit for the CP camera when needed. He also supplied the second 9mm. It was one lens I had not been able to find on eBay. He also modified both 9mm lenses for Super16mm.

My experiences with flare are that it is very much there to be provoked in a test environment, however in most real world circumstances where the wide-open aperture would be needed, flare has not been an apparent problem. Likewise in the practical real world, the sharpness of these lenses wide-open remains better than the Angenieux zooms, by far better than the 10 x 150 and a trace better than the 17.5 x 75 in its comfort zone.

These two clips might be of interest.

http://www.youtube.com/watch?v=A-AOBZsmz_Q

Shot with Angenieux 17.5 - 75 zoom, Kinoptik 5.7mm and CP Ultra T 9mm.

http://www.youtube.com/watch?v=NvZHQNY7IMY&feature=relmfu

Shot with Sigmatel-for-Nikon 135mm, CP Ultra T 16mm, CP Ultra T 12.5mm, CP Ultra T 25mm, though I cannot now remember exactly any but the tracking shot with the 16mm.


In the prison cell shot of the guard, my DoP counselled me to make sure I kept a note of the lens and not to lose or let it be damaged.

In the orchard clip tracking shot, before the image was coloured up from raw, ( the editor's personal preference versus grading off the looks ), there was a very faint but visible grey patch travelling with the camera occupying about a centre third of the image. You will also observe a flash flare from the nightsoil can as it is emptied into the hole. I think this may also be sensor-lens reflective interaction. I am not getting all heartbroken over it.

 

[Albert Schrijvers]

Hello Robert,

I myself own a CP GSMO camera and don’t have plans to move to digital to in the near future. I couldn’t afford it anyway, being an amateur…

About the orchard clip: I only saw the flare issues after I viewed it a second time in slomo, after I read your remarks about it.
For the rest: fantastic images: terrific tonality and the highlights are very good as well.

 

[Robert Hart]

Albert.


These were basically my last hurrahs in shooting film. Our nearest lab is right over on the other side of the country and the film has to run the gauntlet of clowns with xray scanners.

http://www.youtube.com/watch?v=W-r6sg1RQ0Y&feature=relmfu Launch of replica of H.M.Bark Endeavour in 1993. Lens was an Angenieux 10 - 150 which as you will observe vignetted on wide shots. There was also a shutter timing issue with the Super 16mm frame which I had not caught.

http://www.youtube.com/watch?v=43KPM55B-FU ANZAC Day March. Perth Western Australia. By this time the Angenieux 10 - 150 has gone quite yellow and I found to fix it and get a rather mundane lens at best was more expensive than buying a "new old stock" Angenieux 17.5 - 75 from Ken Hale. They were inventory left over from the curtailed production run of the CP GSMO model which you have.


If I could shoot film on my projects affordably I still would. There's a loose crew of indies here who still prefer to shoot film. Their last was done on an Aaton Super16mm with production value-adding like professional lighting, sound recording and professional DoP Alex McPhee. They kept the shooting ratio really tight and disciplined and found a good deal on getting it scanned. It looks absolutely the best all graded up.

I ended up buying the SI2K because it was a demonstrator going for a good price and was going to be lost to Western Australian production. I did not intend to keep it but move it on to another buyer. Then the REDs came out and there were eight of them over here in pretty quick order. That pretty much fixed my scheme but I am happy enough with what I have now that I have it. Full 35mm sensor would be nicer but that's for another day well ahead from now if at all.

For the orchard clip, I had the benefit of a cameraman and a professional DoP overseeing him and a soundie, so I could attend to actually directing. That is not my talent as I am more of a writer.

 

[Albert Schrijvers]

Hello Robert,

I should have figured why the SI2K was that good: it was film then!
I agree that working with film these days is difficult and expensive. I send my films to the Barandov Studios in Prague, Czech republic, 900 kilometres away from my place in Holland. It cost me a fortune in shipping costs and 4 weeks tot see my print (I don’t even want to think about xray scanners). I try to practice every shot before I actually shoot.
About the Angenieux 10-150 zoom: I use the Cooke 9-50mm zoom for standard 16mm. It’s a terrific lens and it can by had for a ridiculous low price as 350 Euros on eBay these days. Of course it only covers 2k in Red, or even not that.
BTW, if you have definitely given op shooting with your CP16R I might be interested in your CP to Nikon adapter… ;-).