URSA Broadcast Lens choice..SD=>4K?

I recently upgraded my camera setup to the URSA Broadcast and started off with the Canon EF mount so I can re-use my lenses, but also wanted a parfocal broadcast style lens as that is what I'm used to and really liked about my old Canon XLH1 setup (I have the 16x manual lens) so purchased a cheap Canon YJ20X8.5B4 KRS.

This allowed me to get going with the camera straight away and kept cost down. But, I have noticed significant softening around the edges of the frame, roughly in a circle shape, on some shots. Today I did a quick lens test against a brick wall and found that it is less obvious (but still there) on smaller apertures. Some screen shots attached. These are recorded in 4K and zoomed in x2 to show the bottom right of frame. The top left of frame is more or less the centre of the picture and is in focus.

f/2.0 HD Zoom x2

J20X8 F/2

YJ20_F2.0.jpg (811.24 KiB) Viewed 1889 times

f/11 HD Zoom x3

Y20X8 F/11

YJ20_F11.jpg (859 KiB) Viewed 1889 times

Clearly stopping down introduces many challenges.

I am considering getting the 4K LA16x8BRM Fujinon lens. Can anyone with more lens experience vouch that such a lens would yield as good if not better results optically than stills lenses (which don't have the softening I have seen on the B4 SD lens. Is the issue I am seeing one that is related to the Y20X8 being an SD lens? Is that the purpose of qualifying lenses as HD or 4K, so that you have that consistency across the range?

You can see there is a lot of falloff in the corners as well. The big difference in the quality of broadcast lenses is how they handle the extremes of aperture and focal range. 75mm @ f5.6 you can't find a bad lens. 800mm@f2.8 and a 150K lens is disappointingly soft.

That Canon YJ was never a top dog even in SD.

The Canon YJ20X8.5B4 KRS was a good lens for SD, but expecting a lens designed for 400-600 line TV camera to perform adequately, let along wee, on a HD larger sensor camera is asking too much. If you want better image quality, then you need to get at least a good HD B4 ENG Zoom lens.
Cheers

If you want better image quality, then you need to get at least a good HD B4 ENG Zoom lens.
Cheers

I thought as much. I got the lens for a song and was quite impressed with it overall, but it does depend on what you're shooting and the settings. I have not seen this kind of issue in any lens before, but I have only been using HD, the URSA is my first 4K camera.

Even with the XLH1 setup, the 16x lens is rated as SD, but hasn't shown these type of issues and worked perfectly for HD. I'm interested in getting the 4K LA16x8BRM Fujinon lens, but can't get a demo. I would expect not to see these kind of issues at all in that but as Howard said

800mm@f2.8 and a 150K lens is disappointingly soft.

, so I just need some confidence that if I invested in that lens, then it would be uniform across the frame. HD B4 lenses seem to be around the same sort of price.

Would the BMD B4 mount adapter also be at play as this has glass designed to converge the the image and expand it?

The XLH1 lens and sensor are matched, so the issues you are seeing with the UB and SD (standard definition) were corrected. When that SD ENG lens was made, TV/Cameras were 200-400 lines of resolution, now it is 4X+ that, so for what it is, the old lens is doing OK, but a HD lens, let alone 4K it is not. Every part of the image chain from lighting in the set, filters, lens, and sensor all determine the final quality of any image. Skimp on any component in this chain, and the results in image quality will be degraded.

Yes the Opticsl block in the BM B4 Mount is a 1.5X teleconverter, so it is going to slightly soften the image, and it corrects the RGB projection of the lens to match a single sensor. So the better a lens you use, the better the results. The new Fujion 4K ENG zoom that is developed for the UB, will give the best performance, followed by 4K and HD ENG zooms. The new Fujion Zoom, is corrected for the B4 Mount.

What would be even better, would be a full Servo ENG style zoom, made for the UB’s 1-inch sensor, in a PL mount that would eliminate the B4 corrected mount, and then you have an even better image. And the UB becomes a S16 Cinema Camera, that handles like an ENG camera.
Cheers

Thanks for that Denny, very informative. I totally agree about all the elements that go towards a final image, but I have been in "pixel watching" mode to get to understand the limits of the lenses / equipment I have. One surprisingly good lens I've used was the Canon 100-400mm. In fact all the EF lenses performed ok, but still lenses are horrible to work with in my opinion.

Very interesting about the Fujinon lens. I guess if it has been made especially, including taking into account the B4 mount, then it's likely to perform very well.

What would be even better, would be a full Servo ENG style zoom, made for the UB’s 1-inch sensor, in a PL mount that would eliminate the B4 corrected mount, and then you have an even better image. And the UB becomes a S16 Cinema Camera, that handles like an ENG camera.
Cheers

Now that would be quite something! I love working with ENG lenses as they are quick to frame and focus and like you say, a PL mount version would be an awesome combination.

For what you get, the Fujinon MK series are on my wishlist. Especially like that the SLR Magic 1.33x-65 Anamorphot adapter was designed for the MK zoom lenses with the 82mm screw-on is threads. I was reluctant to go with that Anamorphot but know it’s my go-to choice paired with the SLR Magic 32mm APO prime until I can use the Fujinon 18-55mm MK. If anyone wants to go that route, I’m controlling focus of both lens and Anamorphot synchronously with the PD Movie follow focus.


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I can tell you, you must have some luck with the SD lenses..

I have some that are razor sharp, i had some that were soft. Even with the same lens type.
Late SD helps a lot. But i have some YJ12, YJ18 lenses that are sharp. Sold off the ones that were not good enough.

The same applies to box lenses.. I'm blessed with my 66x box that is up to 60x zoom very good.. After that there is some fall off noticeable. But those box lenses have soft limits you can adjust. So mine is locked off in 60 / 62x zoom.

But i have seen Late SD box lenses that were way too soft.. So it all depends on luck.. If i buy a lens.. Always put it on the camera and make a few test shots to really see what it does.