Thread: Speedbooster for the UMpro: Full frame to to S35

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  1. #21  
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    Paul, I am not trying to be negative, just realistic. There is ore to,optical designs than just putting lens elements on the back end of a lens. Not done correctly, you can reduce the lens sharpness, IQ and add other optical,artifacts. I was passing along what Brian C. had previously stated about doing this. Can it be dine?. Possibly, but the question is how much do you need to modify the camera to make it happen.

    Also, you need to determine if there is sufficient market demand for such a product or modification, to make it economically doable.

    These are the issues I see trying to do this. Another member here has managed a Nikon F adapter/Spled Booster in the Ursa Turret, and he looked at what it took to do this, measured the UM Pro, and determined due to the filter elements in the camera optical patch, between the lens mount and the sensor, there was not enough room for the SB optical elements that he had previously used.
    Cheers
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  2. #22  
    http://www.newsshooter.com/2017/09/1...2-red-cameras/

    A speed booster for the red cameras. We knew this could be made, but cool this is being produced. They are looking into other cameras like the Alexa mini. The Alexa mini has similar problems to the Ursa mini pro as it has nd filters restricting the distance to the sensor, so if they release the mini version yhen there's a chance they can make a ursa one. Hopefully cheaper than 3500 euros!
    Paul Ross Jones


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  3. #23  
    For the ARRI ALEXA, I think that there would have to be alteration within the camera body and/or a redesign of the Caldwell optical cell. There are really very limited options and workspace to design within. As with the big URSA, there would be a limitation on just what PL-Mount lenses could be used if they remain usable at all due to the 4mm approx shortening of the flange to focal plane distance which is introduced by the Caldwell optical cell.

    According to the Hanso Innotech's information on their website, they have used a "modified optical block" from Caldwell. With a 4 weeks delivery time I suspect they are making the devices to order. From the description my guess is they are using the same 0.71 "Ultra" optic I have used on the big URSA. I'm not getting much love from BM or Caldwell or Metabones, so maybe an officially sanctioned one is in the works for the BM flagship from this or another outfit.

    The modification for the RED DSMC2 platform may be purely mechanical, like taking some material off the rear diameter of the Caldwell optical cell and maybe some off the threaded section of optical cell to allow clearance in the DMSC2 camera throat but I am only guessing wildly. By integrating the OLPF material in their product, my guess that the original RED OLPF and maybe its holder have to be removed to provide clearance.

    They have gone the extra mile compared to my meagre efforts in that they have integrated the mount assembly and the support of the optical cell into a single module. I took the wimp's way out with separated two-piece arrangement. Hansa Innotech's arrangement is as donkeyproof for owner installation as it can be made and I respect their good work.

    It appears that the thread support for the optical cell remains and with it, an option for fine adjustment. I doubt this would be necessary if correctly collimated lenses are used. A zoomed view of the device shows the start of a thread.

    I think the URSA Mini Pro with its two ND filter wheels throws up a different can of worms. It may be that with the IR filter removed, there "might" be sufficient clearance for the 0.71 optical cell but it would be a big "if". No one's URSA Mini Pro has gone under a bus or over the side of a boat yet, so I have no exemplar to work from. I am not about to go buy one just to pull it to bits.
    Last edited by Robert Hart; 09-19-2017 at 03:33 AM. Reason: error
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  4. #24  
     

  5. #25  
    froess. That's the URSA Mini 4K and 4.6K. The URSA Mini Pro has less available workspace within the camera throat without possibly destructive or crippling modification.
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  6. #26  
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    Yes, they talk about it in the link. The man who managed to create the speedbooster for the ursa said it wasn't possible for the ursa mini pro. That's why I shared the link.
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  7. #27  
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    Is the extra stop really worth this mod for the 4.6k models? The 4k model can definitely use this, but the 4.6 sensor is already pretty good in low light as it is. Also going from cinema Super 35 to a still photography standard doesn't make sense to me, especially since you're not getting the real benefits of an actual FF sensor's extra photosites. Not to mention all the possible imperfections you'll get from the additional piece of glass.
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  8. #28  
    Quote Originally Posted by TheInternet View Post
    Is the extra stop really worth this mod for the 4.6k models? The 4k model can definitely use this, but the 4.6 sensor is already pretty good in low light as it is. Also going from cinema Super 35 to a still photography standard doesn't make sense to me, especially since you're not getting the real benefits of an actual FF sensor's extra photosites. Not to mention all the possible imperfections you'll get from the additional piece of glass.
    The full frame, vista vison look is the most important thing. The lens quality is better as you are reducing the magnifications.
    Paul Ross Jones


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