RED Prime Lens Set

[Matt Uhry]

You guys are all kidding... right?

Jim

Not Kidding at all.

Here's the approximate horizontal angle of view of the proposed focal lengths at 4k:

15mm 73.7 deg
18mm 64 deg ( missing )
25mm 48.5 deg
35mm 35.6 deg
50mm 25.5 deg
85mm 15.1 deg

It's a hell of a big leap between 15mm and 25mm. For many DP's 15mm is a specialty wide and an 18mm is the wide end of your usual set. It's called a "set" of primes because they are all the same T-stop.

I'm glad you made the 18-85 and I'm glad you are planning to make a 15mm prime. I'm just talking about what I would expect in a prime "set"

Matt Uhry
www.mattuhry.com

 

[Dj Joofa]

Generally it has to do with wavelength convergence. Film has multiple color layers, so a "perfect" film lens would have red, green and blue converge at slightly different flange depths. Blue would be the deepest, followed by green and red up front [if memory serves].

I think blue wavelength has the shortest focal length and red longest. I tend to think that the first layer in a film is blue, but I could be wrong.

Conversely, Bayer-pattern digital sensors are "flat" - all three colors exist on the same plane. As such, when one is designing a lens for a digital sensor, the goal is to make all wavelengths converge at exactly the same flange focal depth.

Not sure what you mean by "flat". Blue has the shortest wavelength and hence least penetration on the silicon. Green penetrates more and red the most. That is one reason it is difficult to filter out infra red as it is longer wavelength and penetrates deep down into silicon. I think green wavelengths penetrates at an optimal depth and that is why it response is typically better than red/blue.

 

[Jannard]

Not Kidding at all.

Here's the approximate horizontal angle of view of the proposed focal lengths at 4k:

15mm 73.7 deg
18mm 64 deg ( missing )
25mm 48.5 deg
35mm 35.6 deg
50mm 25.5 deg
85mm 15.1 deg

It's a hell of a big leap between 15mm and 25mm. For many DP's 15mm is a specialty wide and an 18mm is the wide end of your usual set. It's called a "set" of primes because they are all the same T-stop.

I'm glad you made the 18-85 and I'm glad you are planning to make a 15mm prime. I'm just talking about what I would expect in a prime "set"

Matt Uhry
www.mattuhry.com

Matt... no, I'm asking if you are kidding about us not knowing. Do you really think we don't want to get an 18mm in the mix as soon as possible? Really?

As I said, there is a lot more behind developing a set of primes than just saying... "this is what I need"!

Jim

 

[Jannard]

We try to keep you guys posted without having to tell you what we eat for breakfast. But more and more there is a definite gap in what you want and what it takes to pull of this whole project from scratch. Trust me when I tell you it is way more difficult than you could ever imagine. Companies are in business decades before they have credibility to compete at the top of this industry.

We are listening, and have made many changes based on the feedback of this group. But we are not "dumb as mud". If we can't do something, it is more likely that you are naive in the development process than we are in trying to do the right thing. This thread is frustrating me... greatly.

Of course we know how important an 18mm lens is. Do you know anything about developing one? Or do you just assume that you push the "I need an 18mm lens button"?

Jim

 

[Matt Uhry]

Matt... no, I'm asking if you are kidding about us not knowing. Do you really think we don't want to get an 18mm in the mix as soon as possible? Really?

As I said, there is a lot more behind developing a set of primes than just saying... "this is what I need"!

Jim

My Apologies Jim, I'm not privy to what goes on behind the "Red Curtain".

Did I mention how freaking great I think the camera is ? It's freaking great.

Matt Uhry
www.mattuhry.com

 

[Jannard]

My Apologies Jim, I'm not privy to what goes on behind the "Red Curtain".

Did I mention how freaking great I think the camera is ? It's freaking great.

Matt Uhry
www.mattuhry.com

Thanks, Matt. I'm a bit testy tonight. We are trying so hard to get things done, but sometimes it feels like no matter what we do it will never be enough. Pretty discouraging.

Jim

 

[ericyoung]

...Its great that they will be the 1st Designed for Digital although I'm yet to understand what they means in reality...

To add to Brook's educated guess about RGB focal planes - I would also guess this means the back elements are multicoated to reduce internal reflections between the sensor/OLPF (which are typically more reflective than film) and the back elements - something which lenses specifically designed for DSLRs already do.

Also the final light path would be made as orthogonal to the sensor as possible as sensor photosites are less sensitive to light coming in from an angle which may be a factor especially with wide angle lenses.

 

[Dj Joofa]

To add to Brook's educated guess about RGB focal planes

There are two issues here:

(1) focal length of blue light vs. red light
(2) ordering of layers in a film negative.

Both (1) and (2), incidentally depend upon the (shorter) wavelength of blue light. In a naive implementation without correction for chromatic aberration, one might think that blue layer is the top on a film negative because blue is focusing first. However, more sophisticated lens systems (that use a multitude of lenses) might like to to correct for chromatic aberration, then what should be the ordering of the layers on the film negative? I would tend to think that even in that case, it makes sense to have the blue layer as the top layer as blue being shorter wavelength would penetrate less than red.

 

[Brook Willard]

I think blue wavelength has the shortest focal length and red longest. I tend to think that the first layer in a film is blue, but I could be wrong.

Yeah, I figured I was wrong on a few points... it's been a while since I've played around with film.

Joofa makes very good points. I expect that I was simply wrong in my layer ordering and wavelength description. The concept is sound, but I buggered up a few details.

Thanks, Matt. I'm a bit testy tonight. We are trying so hard to get things done, but sometimes it feels like no matter what we do it will never be enough. Pretty discouraging.

Jim

Jim, I know you don't need to hear it from me... but you guys are kicking serious ass either way. It is almost in our nature now to ask for more than is offered... and certainly to ask for more than is possible in a given time frame or at a given price point.

In the way that you looked at your DSLR and asked "why not 24 frames?", we now look at a 4K camera and accessibly priced lenses and accessories and ask "why not more?" Yet while you took the reins and made it happen... we choose to demand features from the comfort of our desk chairs. So take it with a big grain of salt.

Some days the forums are all love and worship of RED... and some days the forums are all complaints, demands and disappointment in what we've already received. Both are obnoxious in their own way... but one seems to yield results and/or information.

If it wasn't in our nature to demand more, we'd be in a cubicle. Keep kicking ass.

Oh, and send me a demolition camera... :whistling:

 

[Evin Grant]

Jim,
I think the response to the lack of an 18mm may be because a lot of us (naively) don't see this as a set of lenses that is marketed to the larger community. Primes are the 35mm shooters bread and butter, especially cinema and commercials and so a few very vocal pros here (especially me) see this as our #1 interest beyond the camera system it's self. The EFP, corporate and low budg Redusers are more disposed to go with the zooms or Nikkors than a prime set that cost twice as much or more and requires a slower more deliberate style. But again to the vocal minority this is the holy grail, we lust after S4s and Ultra Primes and beg the heavens for a Set of lenses we can both adore and afford. I purchased my 20 year old Zeiss T2.1 prime set in good but not great condition for the same price as your set will be new! I could probably turn around and sell it foe $25K tomorrow because the Red One has created such a demand for good, attainable primes. In the end you need to do what's good for the books but we all really hope in our heart of hearts that, even if it cost's a few thousand more you'll at least give us the option of swapping for an 18mm T1.9. This is our sincere dream and you are already soooo close to making it a reality. I will say no more on the subject and leave your work hoping you understand that we beg because we love, and whatever you decide we will of course appreciate your efforts.

 

[Jarred Land]

Epic Films.... Settle Down. (again)

I don't think Evin is still asking for the 18mm. He is just expressing his opinion in a courteous manner.

That said.... I think everything that needed to be said has been said here.. time to close it down.