Introducing new wide zoom!!!!

[FocusOptics]

Hope to see all of you at the NAB come and see our ruby series wide zoom
Stuart

 

[FocusOptics]

Thank you!!!

Thank you!!!

Good day,

we want to thank everybody for stopping by to take a look at our ruby at the nab, and also want to thank those of you who put in your order. Just for your info, we will be posting footage that was taken on the red and we will also be putting our ruby into the s.a.l.t test.

Stuart

 

[Matthew Duclos]

Good to hear.
I can assure you the test will be nothing less than professional.

 

[BigLu]

I wonder if Matthew and Stuart are ever going to make a Lens together...

 

[FocusOptics]

Woo-Hoo!!

Woo-Hoo!!

Hello Everyone,

I just wanted to share some exciting news with all of you, we just went to Otto Nemenz International in Hollywood, and we put the Ruby lens 14-24mm T2.8 on there projector, Dan Lopez and Otto commented that at 14mm the lens is just as sharp as a 14mm master prime. The image does not fall out at all at the extreme edges of the format which is 35mm full chip. This is very exciting! =)

Stuart

 

[chuck colburn]

Hello Everyone,

I just wanted to share some exciting news with all of you, we just went to Otto Nemenz International in Hollywood, and we put the Ruby lens 14-24mm T2.8 on there projector, Dan Lopez and Otto commented that at 14mm the lens is just as sharp as a 14mm master prime. The image does not fall out at all at the extreme edges of the format which is 35mm full chip. This is very exciting! =)

Stuart

That's great. Does it hold focus as you zoom? Or that is to say how far out of focus does it shift at the two points of the "S" curve.

 

[FocusOptics]

Zoom curve

Zoom curve

That's great. Does it hold focus as you zoom? Or that is to say how far out of focus does it shift at the two points of the "S" curve.

Chuck,
The zoom holds focus threw the whole Zoom range. And the and does not image shift also the T stop is a true t2.8
Stuart

 

[Michael Lindsay]

Chuck,
... also the T stop is a true t2.8

I'm impressed and a perhaps a little confused by this... how did you manage this?

kind regards

Michael L

 

[FocusOptics]

I'm impressed and a perhaps a little confused by this... how did you manage this?

kind regards

Michael L

Michael,
25 years of optical experence helped make this happen
Stuart

 

[Michael Lindsay]

Michael,
25 years of optical experence helped make this happen
Stuart

That bit I might of guessed ;-)... it was the details I was hoping for?

I'm assuming the original lens was a 'little' conservatively marked?

regards

Michael L

 

[Evin Grant]

Yes the original Nikon is probably more like an F2.6 at 14mm. It does ramp a slight bit toward 24mm, ending at a T3. This is not unusual, even the Optimos ramp a tiny bit.

 

[chuck colburn]

Stops change on zooms, that's fine. But how much does the flange focale depth change thru out the focale length change? It's a given that it will.

 

[FocusOptics]

back focus

back focus

Stops change on zooms, that's fine. But how much does the flange focale depth change thru out the focale length change? It's a given that it will.

Chuck,
The focus is constant threw the zoom you do not have to refocus at any point.
Stuart

 

[Matthew Duclos]

Flange focal depth would only change if the mount was moving... Which I don't think is the case. (in fact I know.)

Chuck, are you referring to loss of focus throughout the zoom due to internal mechanics?

 

[FocusOptics]

the image

the image

Flange focal depth would only change if the mount was moving... Which I don't think is the case. (in fact I know.)

Chuck, are you referring to loss of focus throughout the zoom due to internal mechanics?

The image does not go soft all the mechanics have been changed from the still version.
Stuart

 

[Stephen Williams]

I think Chuck is talking about the S curve of the zoom lens focus.

 

[Matthew Duclos]

I think Chuck is talking about the S curve of the zoom lens focus.

In that case, it would be entirely up to Stuart's zoom mechanism design.
Nothing to do with flange focal distance other than the fact that error in zoom curve can be compensated for by adjusting back focus and effectively splitting the difference in the zoom curve.
I think Stuart said he redesigned the focus mechanism (he must have to obtain proper focus rotation).
In which case I can't imagine he would overlook something as critical as zoom curve. But I would be curious to know how much of the original converter group is adapted.
This all begs another query. What sort of optical mechanical adjustments are included?
Stuart, did you adapt any axial alignment recourse for critical optical groups? Or does the lens not really require such calibration?
Regardless, this conversion looks very well done to me. Bravo, Stuart.

 

[chuck colburn]

All zooms have focus shift as they vary their focale length. The best have very little. But all of them have some. You can get it spot on at the long end (front focus) and the wide end (back focus) and at a spot about 1/3 to 1/2 way done the focale length range. The mechanisim that contols focus shift is called the compensator. It is the group of moveable elements behind the variator group which is the one that varys the focale length of the lens. As lens mechanical design, optical formula and glass types have improved over time the focus shift has become less and less. But it does exist.
And it can be measured.

 

[zak forrest]

Has the connoisseur du glass given his opinion on the RPP's yet? Did I miss something?

 

[Matthew Duclos]

Zak,
I haven't yet. I'm visiting RED on Thursday (I think).
I'm sure I'll have some words to share at that time.