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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Red lenses

Matt Uhry said:
It was a 10foot distance,not distance. projector was OK. Results confirmed on camera.
Click to expand...

Not quite following you there Matt. But I guess it doesn't matter if the camera agreed. So what your saying is if you focused at the long focal length it did not hold focus as you zoomed to the wide end?

Just a couple of after thoughts about the 18-50 zoom. While I haven't had my hands on one, I do know that most zooming optics can generally be improved upon from their factory performance. Adjustments done to the front (focusing) group, the second or what is called the variator and the third or compensator group can most always lead to improved tracking, focus holding and chromatic correction. And of course final back focus adjustments done to the rear or collimation group (and some tracking errors also). The overall good notices on this lens would make it worthwile for some optical repair facility to invest the time to learn the particulars of this lens.
 
We mounted the our lens on a project in Sydney and did almost the same thing.
We got similar results - but no chromatic aberration to report.

These comments by the Swiss are plain wrong. I have spoken to three rental houses locally and the answer is the same - not as good as a $35,000 prime - much better than one could have expected, its an impressive lens for the price.

Mike
#22


Matt Uhry said:
We put Gibbys 18-50 zoom on the lens projector at Panavison Calgary and here's what we found:

-the lens is very sharp. at any focal length I could get 200lp/mm in the center and at least 100 at the edges ( a bit less good as you go towards 50mm )

-It's very low distortion. Really good. a little bit of moustache on the wide end and barrel distortion on the long, but really good nothing that's going to be a problem in normal shooting, better than lots of respected lenses that are out there.

-good field illumination. image is of even brightness across frame.

-very minor chromatic aberation a little purple fringe going inward at the far edges. did I say it's minor?

-on Gibby's lens the focus was not exactly to scale. This could be tweaked by a technician and made better. but at 18mm 10 actual feet focused at 20 feet on the scale. Same was true at 50mm 10 actual feet focused at 13 on the scale. The lens needs to have a little (.02mm ? ) material removed from the mount. Not a big deal, but would be nice for a new lens to arrive in better tune.

- There was a bit of image shift most pronounced at 50mm when you focus the image jumps up and down a little. It's pretty minor, maybe 1-2% of image height but this kind of thing tends to worsen as the lens gets worn in. No observable image shift at 18mm.

It's cool how close it focuses, but I would give up the last foot of of close focus away if it got me a more expanded scale from 4-50 feet.

This is just what Finner, Gibby and I observed on this one sample lens - your results may be different.

All in all it's a good value, with just a little care you can shoot great images with it. No excuse from the lens if you shots aren't great.

Matt Uhry
www.mattuhry.com
Click to expand...
 
chuck colburn said:
Not quite following you there Matt. But I guess it doesn't matter if the camera agreed. So what your saying is if you focused at the long focal length it did not hold focus as you zoomed to the wide end?

Just a couple of after thoughts about the 18-50 zoom. While I haven't had my hands on one, I do know that most zooming optics can generally be improved upon from their factory performance. Adjustments done to the front (focusing) group, the second or what is called the variator and the third or compensator group can most always lead to improved tracking, focus holding and chromatic correction. And of course final back focus adjustments done to the rear or collimation group (and some tracking errors also). The overall good notices on this lens would make it worthwile for some optical repair facility to invest the time to learn the particulars of this lens.
Click to expand...



Yeah, sorry the last comment was made from my phone between shots and hard to type. I agree with you that it's more represents the need of a tune-up or even maybe set up and not a systemic problems with the lens. Fixable in my estimation, good choice for those looking for a lens of that size and in that price range. ( and who want to get a bit more than what they pay for )

Matt Uhry
www.mattuhry.com
 
How does the 18-50 perform with rack focusing, is there breathing noticeable ?

Manuel
 
Ive done some resolution chart tests here:

http://www.projectred.net/forums/viewtopic?id=33

I've been shooting with the RED 18-50mm for a few weeks now. The consensus is that its a pretty amazing lens for the price. Very sharp glass.

Where the lens could use some improvement is in the mechanics. Its more of a variable prime than it is zoom. There is considerable 'play' on the barrel when zooming, that is, you can slightly wiggle the barrel back and forth without changing your focal length. This may cause a judder if you were trying to pull a smooth zoom during a shot. I tend to never zoom while shooting so its not so much of a problem for me but for ENG style production, it could be. Also, the focus marks are too compressed to dial in focus accurately. Ideally they would be much more spread out but I assume the mechanics required to do this are more complex and thus too expensive for a $6,500 lens.

Overall Im very happy with it, it's a pretty incredible offering for $6,500.
 
My 2c: Really small, light, nice.

Suggestions: when / if they make the 18-85 or revise the 18-50, I'd love to see it done to a similar quality level as their 300mm prime, which felt solid to me. Beautiful feel.

Specifically:
- less play in the mechanism (I thought it was not just zoom but focus too on the one I played with?)
- somehow expand the focus scale - the distance between 10ft, 20ft and infinity is a tad small (would happily sacrifice CF for this)
- less breathing (again, can sacrifice CF for this)
- smoother mechanism - the one I played with felt a little rough on both zoom and focus compared to, say, the Red 300mm (if this makes it a bit heavier, that's fine by me)

Again, not huge problems but after just playing with their 300mm prime there was a significant ergonomic difference.

Matt, I think you agree but are just being tactful? Gibby, Evin? You guys agree or not?

Chuck, you talked about sending it somewhere for a tune up... hope that works! If the ergonomic niggles could be fixed easily (expanded focus scale notwithstanding) this would rock.

Bruce Allen
www.boacinema.com
 
I like the lens a lot but I'm not going to buy one. Less because of the optics or build and more because of range. I need something more like an 18-100 or 20-100 Cooke. I'll be interested if Red does finally get the 18-85 done what that optic is like.
 
Any opinions out there as to how the Red zoom compares to a Cooke 18-100?
 
manuelwenger said:
How does the 18-50 perform with rack focusing, is there breathing noticeable ?

Manuel
Click to expand...

would not be my 1st choice on a rack shot - if we are talking narrow DOF/tight rack anyway -

There is a bit more play than I like - but as others said - the lens it sharp as hell and for the price, a very good value.

I don't really think of it as a ZOOM - I'd say it's a variable prime.
 
jimarri said:
Any opinions out there as to how the Red zoom compares to a Cooke 18-100?
Click to expand...

Different animals, the cooke is corrected for breathing, has great mechanicals, goes to 100mm and weighs 12lbs. Needs a 5x6 or 6x6 matte box. It's big and shoots very nicely. Fine for tripod work but not good for hand held.

The Red lens is a compact Zoom.

If you got both lenses, or the 18-100 and some primes that would be the beginning of a good lens package. You really should go somewhere and try out any lens you are interested in. Personal taste and the kind of jobs that you work on come into play here to.

Matt Uhry
www.mattuhry.com
 
I'm hoping the RED Primes will have a better build like the 300mm as the Zoom I played with at IBC was poorly made.
 
I would be interested to learn the findings of anyone who has tested the 18-50 in terms of aperture marking accuracy. Did anyone perform a controlled test and would be willing to share their results?
 
Does anyone know who is making the lens...
 
only Red knows ...

taking a wild guess - glass could be from Sigma's 18-50 CF F2.8 ... outer housing by ? ...
 
outer housing by?... someone who should have better QC

The one I saw at IBC had loads of play in the focus and zoom gears. Seems a shame RED have done so much on the camera to be let down on the lens.
 
Is the play in the lens something that could be resolved by a lens repair service? I have been planning on purchasing the 18-50 since I heard the announcement at NAB, but things like this make me scared. I understand 6500 is very cheap for a lens like this, but I don't have 40 grand for the lightweight Cooke zoom, and a used 18-100 Cooke is impractical for me because of the weight. I also don't really want to go the Nikon or Eos direction because of dealing with mount changes between rentals and whatnot.
 
I'm in the same boat. I was going to purchase the Zoom until i saw one for real.

Its crazy that you would have to take a brand new lens to a repair center and pay to have it work correctly.

Now I'm almost about to purchase a set of Zeiss Standard Speeds but have heard they give a porthole effect on the 16, 24, 32mm.
 
Yeah, I just saw the lens for the first time too, but it was a complete run n' gun situation at night while trying to hold the camera on my shoulder with no shoulder pad(painful) or handles in a dark car while driving around the city for 30 minutes. So I didn't really get a chance to evaluate it too closely.

And yes, it would be crazy to have to take a new lens to a repair center, but if it eliminated the play... Any guestimates on how much that might cost?
 
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