Red lenses

[Proteus]

Everything will be more objective a week or two after RED is released...

Now if RED can provide 1080p digital output by downconverting from 4k (which it should) then I will definitely use a still 35mm lens (with FF gear etc) to take advantage of the extra definition provided from the downsampling. I consider this an absolutely critical feature. I hope the RED team won't underestimate it.

BTW, if the light is adequate you can always stop down the lens a couple of stops to increase the depth of field and make focus easier...
So if I get RED I would avoid window mode except if I want 120fps or digital stabilization, but this can also be done with a full frame lens while the opposite is NOT true...

Besides, why get RED if your are not going to take advantage of 4k either for higher res or for the advantage of downconversion?
You could get Silicon's for less money.

 

[Greg Lowry]

Now if RED can provide 1080p digital output by downconverting from 4k (which it should) then I will definitely use a still 35mm lens (with FF gear etc) to take advantage of the extra definition provided from the downsampling. I consider this an absolutely critical feature. I hope the RED team won't underestimate it.

I agree.

BTW, if the light is adequate you can always stop down the lens a couple of stops to increase the depth of field and make focus easier...
So if I get RED I would avoid window mode except if I want 120fps or digital stabilization, but this can also be done with a full frame lens while the opposite is NOT true...

I don't follow the second part of that statement.

Besides, why get RED if your are not going to take advantage of 4k either for higher res or for the advantage of downconversion?
You could get Silicon's for less money.

The point is that one can grow into the RED's higher-end capabilities without having to get an entirely new camera.

 

[Proteus]

I mean, with a full frame lens you can have all the features including full sensor advantages and whenever you want you can switch to windowed mode (of course with the associated consequences as is the increased focal length etc). With a smaller format lens you'll be stuck always to the smaller ccd area.

 

[Proteus]

The point is that one can grow into the RED's higher-end capabilities without having to get an entirely new camera.

Ok, this can be a reason...

 

[nalu]

more

more

Great thread guys, really enjoying it and learning!

The point is that one can grow into the RED's higher-end capabilities without having to get an entirely new camera.

Also can't we anicipate that RED at 1080p will outperform Silicon's results????

I'll be looking at either a ENG style setup as described by Gibby a few pages ago or a S16 zoom - hard to decide between the two. I'll be a one man team for shooting and also do the majority of my own post production so 1080p and 2K will be the only formats I will deal in. Unless, I'm rented for 4K project.

I'm planning to build a water housing for RED - predominantly for above/just below water shooting (i.e. not deep diving) - action sports such as surfing etc.
Anyone have thoughts on an approrpiate Prime lens. I'm figuring I'll need something with a massive depth of field (want focus to begin just beyond the housing).
I don't know much about film lenses - what would be the options here??? Need to have everything in focus over a wide distance.

PS - Gibby? did you get my email as requested??

 

[Proteus]

Also can't we anicipate that RED at 1080p will outperform Silicon's results????

If downconversion from 4k will be implemented, it is obvious that it will outperfom Silicon. If not, it will be similar.

 

[Greg Lowry]

I mean, with a full frame lens you can have all the features including full sensor advantages and whenever you want you can switch to windowed mode (of course with the associated consequences as is the increased focal length etc). With a smaller format lens you'll be stuck always to the smaller ccd area.

The problem with this is that still camera lenses (like the Zeiss ZFs) will be fine for use on the full frame, but they become mostly normals or telephotos on a small sensor area.

A lack of wide angle variety is always a problem when using still camera lenses for motion picture use.

 

[Proteus]

The problem with this is that still camera lenses (like the Zeiss ZFs) will be fine for use on the full frame, but they become mostly telephotos on a small sensor area.

A lack of wide angle variety is always a problem when using still camera lenses for motion picture use.

As I posted to this thread http://www.dvxuser.com/V6/showthread.php?t=64025&page=2 it's only a 1.475 multiplier. That's not too much IMO. For example my favorite still lens Nikon 17-35 would be just 25-51.

And a wide prime 11mm would be about 16.2mm still wide enough IMO for many situations.

 

[Greg Lowry]

Well a 25mm on an S16 camera is a normal lens. Consider that Zeiss makes 6mm, 8mm, 9.5mm, 12mm and 14mm wide angles just for S16 format. They offer these lenses because wide angles are very important. Maybe the kind of shooting you do doesn't require wide angles, but most does. And if you look at the range of ARRI Zeiss 35mm format cine lenses, there is a very broad range of wide angles for the same reason. They're invaluable.

For me, the weakness of the Zeiss ZF option is the very limited wide angle lenses (when the full range becomes available, right now it's just the 50 and 85 that are trickling out of the factory). Perhaps an acceptable situation for S35 use, but a real problem for S16.

I think you have misinterpreted Jim Jannard's conversions in the link you provided, because the ratio you quote is for still camera lenses used on the full sensor, not a windowed sensor. But perhaps I have misunderstood YOU. Always a possibility. haha.

 

[Proteus]

Well a 25mm on an S16 camera is a normal lens. Consider that Zeiss makes 6mm, 8mm, 9.5mm, 12mm and 14mm wide angles just for S16 format. They offer these lenses because wide angles are very important. Maybe the kind of shooting you do doesn't require wide angles, but most does. And if you look at the range of ARRI Zeiss 35mm format cine lenses, there is a very broad range of wide angles for the same reason. They're invaluable.

For me, the weakness of the Zeiss ZF option is the very limited wide angle lenses (when the full range becomes available, right now it's just the 50 and 85 that are trickling out of the factory). Perhaps an acceptable situation for S35 use, but a real problem for S16.

There is a misunderstunding (or two) somewhere...
Obviously the focal lengths of the S16 Zeiss lenses you refered, are not characterized in terms of 35mm still format.
So the equivalent focal lengths to 35mm still lenses will be:

6mm S16 = 19.5mm (35mm still equivalent)

8mm S16 = 26mm (35mm still eq)

9.5mm S16 = 31mm (35mm still eq)

12mm S16 = 39mm (35mm still eq)

14mm S16 = 45mm (35mm still eq)

So if you use e.g the Nikon 14mm f/2.8D ED AF Nikkor it will be converted to 20.6mm (35mm still eq) S35 for RED, similar as the wider 19.5mm (35mm still eq) S16 Zeiss.

I think you have misinterpreted Jim Jannard's conversions in the link you provided, because the ratio you quote is for still camera lenses used on the full sensor, not a windowed sensor. But perhaps I have misunderstood YOU. Always a possibility. haha.

Yes, I meant the still lens' focal length increase for full frame "S35".

P.S If you think my calculations are wrong please discuss it...
.

 

[taubkin]

This keeps getting better and better. It's an honor to be part of this wealth of information, and intelligent thinking.

It's also unfair that I get to be listed as "experienced" ammongst the the masters in here here, such as acoreasc, gibby, greg, proteus and etc.

Since we're thanking everyone...

Cheers!

-EDIT- But I still don't understand Proteus's math. If you use a 14mm still lens, but have to use a S16 windowed capture, you'll fall with an equivalent of a 40mm. An S16 16mm lens roughly equals a 50mm still. But sure, if you're using full S35 sensor, a still wide angle can be wide enough for most people's needs!

 

[acoreasc]

thank you Taubkin - but I am helpless infant compared to the guys you listed.....really, like a crying, diapered infant...but I'm learning!

Can at RED or anywhere build a lens conversion chart for s16 and 35mm still lenses to the particular RED Sensor of choice.....just thinking

 

[Emanuel]

I'm somewhat confused by all the fervor over s16 and 2/3" lenses on RED. Isn't the S35mm sensor and the accompanying DOF one of the biggest draws of the camera?

:thumbup:

I truly believe that the latest generation of still lenses from the better optics houses will outperform any of the S16 zooms from the 80s or early 90s. And any of the good 2/3" HD zooms are more expensive than a set of T2 Zeiss primes.

:thumbsup:

It is really not as hard to mount follow focus gears on to these lenses as you may think. Most are designed for professional use and can take the FF pressure just fine. And although the distances may be less accurate you will most likely be using an HD monitor to set marks anyway. I'm all in favor of using cinema glass when the budget and project demands, but blowing $ on a smaller format zoom seems silly to me.
My 2¢.
E.

Posted before by Filmmaker1977, just for example and as to prove...so simple than what offers:

http://www.dandiaconu.com/newweb/mug.htm

 

[Greg Lowry]

Proteus: The points I was trying are simply these:

1. One could use the Zeiss ZF lenses for the RED 35 and S35 formats but the focal length range at the wide end is limited. Not a major issue.

2. For those considering the ZF option for windowed and S16 formats, the ZF's are a bigger problem because of a complete lack of meaningful wide angles. Not very practical.

The reason I listed the Zeiss S16 format lenses was to illustrate how important wide angles are to modern cinematography. I personally would not buy the ZFs if I were shooting the smaller formats, but I'm eager to buy a set to play with for other purposes.

I'm curious to know your level of experience. Feel free to email me if you prefer. Thanks.

 

[Greg Lowry]

I'm not entirely sure i want to wade in on this post because I still don't understand Proteus' point of view, but here goes.

An S16 format 6mm lens may be the equivalent of a 35mm format 19.5mm (i'll assume your math is correct) but the opposite obviously isn't true. So your exercise in lens conversion doesn't help those who are considering still camera lenses for the smaller formats.

Once again I strongly point out that a lens is NOT "converted" to a different focal length when used on a different format. A 10mm is a 10mm no matter what the format. Semantics are important in this discussion and the use of the term "conversion" is absolutely wrong. One reason why this is crucial is that depth of field computations are based on the focal length of the lens.

Read my previous post on this subject for further explanation.

So the equivalent focal lengths to 35mm still lenses will be:

6mm S16 = 19.5mm (35mm still equivalent)

8mm S16 = 26mm (35mm still eq)

9.5mm S16 = 31mm (35mm still eq)

12mm S16 = 39mm (35mm still eq)

14mm S16 = 45mm (35mm still eq)

So if you use e.g the Nikon 14mm f/2.8D ED AF Nikkor it will be converted to 20.6mm (35mm still eq) S35 for RED, similar as the wider 19.5mm (35mm still eq) S16 Zeiss.

Yes, I meant the still lens' focal length increase for full frame "S35".

P.S If you think my calculations are wrong please discuss it...
.

 

[mike the beginner]

Quote: personally can't imagine doing any sort of fast-paced documentary or grab style shooting with a set of primes. By the time you change lenses, your subject has left town or you're dead.
__________________________________
Thats why i could only use primes in scenes when that would not apply. Underwater (part submerged) filming fish close up perhaps. Scenic landscapes with appropriate primes. Hope ive got that right?

Just thought i should mention that Graeme Nattress has already confirmed that Red WILL downconvert the full sensor to 2k in camera and then cropped in post. He also hinted that Red is considering also trying to downconvert from full sensor to 1080p in camera. The comments were made over at DV info. Much discussion has since came about with Mike Curtis mentioning how much of a pain cropping would (IS he said) be from 2k to 1080p. Graeme did come back at him with 4 different options on 1080p. Might be useful to know so thought i would mention.

Thanks again all of you for confirming the difficulty of focusing whilst using s35mm lenses. Great posts there brilliant

My brain cells are still burning though and none more so when Proteus mentions what i am thinking regarding the use of s35mm lens, even the swapping over from full sensor to windowed 2k to get the 120fps on occasions. BUT.....It is the two or three stops to increase depth of field that was lurking in my brain cells. You see my theory learning suggest that because we have such a large sensor AND used with a s35mm lens we have a massive aperture opening compared to a 1/3rd camera. EDIT
AND ADD "to begin with"

IF....artistic options are briefly ignored for now and all you want to film is the whole area in focus then would that not be an option without the worry of crtical focusing. Accepted you loose a lot of low light advantages (important to me) but surely you would still have more low light capabilities than if you were restricted to a 1/3rd ccd with appropriate lenses. What do others think? have i failed to grasp the theory in this situation?

Michael

 

[Greg Lowry]

A "massive aperture" means less depth of field, not more.

T1.4 is a large aperture setting (shallow DOF), T16 is a small aperture (deep DOF).

A T1.4 maximum lens aperture remains a T1.4 maximum lens aperture no matter what the format.

 

[mike the beginner]

Quote: A massive aperture" means less depth of field, not more.

________________________________________

Greg i mention the massive aperture opening as meaning "you begin with a lot of available light using an s35mm lens" and a huge sensor. But you then have a very shallow depth of field and focusing problems.

By THEN reducing the aperture size i increase depth of field and focusing becomes less of an issue. My point being how far can i go doing this but still be well ahead in low light capabilities compared to a 1/3rd ccd camera with oppropriate lenses. Now do you get what i am saying

Michael



This i thought would give you more leeway to close the aperture and increase the depth of field thereby also reducing the focusing requirements

 

[Greg Lowry]

A large sensor isn't necessarily more sensitive than a small sensor. in fact, with currently available large sensor cameras the opposite seems to be the case. And you can only stop down to increase depth of field if the exposure sensitivity of the sensor allows it, so I think your basic premise is flawed. I don't mean to be a hard-ass, I'm just trying to keep the facts straight. Sometimes the terminology you use makes it difficult to understand your meaning, but that's perfectly OK. If I misunderstand you, let me know and I'll try harder to understand.

At this point we don't know what sort of exposure index (EI) rating the RED sensor will have. (You may prefer ASA or ISO. I use EI because it's now the way film stocks are rated and it gives me a frame of reference I immediately understand. It's also the way the large sensor, film-style digital cinema cameras usually rate their sensors.) The ARRI D20, Panavision Genesis and Dalsa Origin large format sensors are rated at about EI 320(ish). Current 1/3" CCD camera sensors generally have a higher EI than that (the DVX's EI is 640, isn't it? I'm no expert on 1/3" CCD cameras, so help me out if I'm wrong).

Hopefully RED will work its magic and come up with a sensor with a high EI rating. It won't be long before EI 1000+ large format sensors are widely available. In fact there is at least one camera with that capability now but the pixel pitch of the sensor is 12.5 microns (red is 5.4 microns). Large pixels help with light sensitivity and low noise, but not as many 12.5 micron pixels will fit on an S35 sensor, thus limiting spatial resolution.

 

[stephen natanson]

Just to heip with the lens "conversions" (may be better to say equivelent lens angle) according to professional (and they get things wrong every now and then) tables and sticking to typical still camera range.

35 photo 21mm = s35 film 14mm = s16 7mm
35 photo 26mm = s35 film 17mm = s16 8mm
35 photo 31mm = s35 film 21mm = s16 10mm
35 photo 39mm = s35 film 26mm = s16 13mm
35 photo 50mm = s35 film 33mm = s16 16mm
35 photo 81mm = s35 film 54mm = s16 27mm

I underlined the same (almost the same) focal length lens in each sensor size to make it clear that a wide angle photo lens becomes less wide in s35mm film format and is a portrait lens in s16mm. Looking at the table, if you are shooting with still camera lenses and using the whole s35 film sensor area, the only lens that you would be missing is the super wideangle 14mm, they are available for 35mm photo cameras but are expensive and worse very heavy with massive front elements. I think that the sensors which are slightly smaller than traditional 35mm used in the first batch of pro and semi pro still cameras such as the Canon Eos range are closer than to S35mm film size and they developed lenses for those cameras which could fit the wide angle spot. The lenses are however very "automatic" and would have to be modified and may also not be sharp enough.

I find the idea of using massive traditional cinema zooms on the red camera ridiculous, even cinema primes are larger and often heavier than the body. Instead of building a cage and fixing the camera to the tripod it would make more sense to figure out a way of fixing the lens to the tripod and just attaching the red sensor to that.

Actually I very rarely use zoom lenses to zoom in shot when I film so I think the idea of using small light photo zoom lenses very pleasent for situations where there is enough light and where a shallow depth of focus is not wanted. Who knows some genius may figure out a way of modifing them to make them behave better (smooth zooming, breathing focus problems etc.). I have an old cinema zoom and it is a horrible lens, one forgets at time how bad some of the old technology was, I am sure that photo zooms are better. May be fun to use on the red however.

One issue which may be a problem is all the amout of extra light going into the sensor area as the lenses cover much more than necessary. In cine cameras stray light reflecting on the mirror mechanism etc. could be a big problem causing general fogging or strange light smears. I am sure the red team is spending time and attention to light baffles and anti reflective surfaces but just in case thought I would try and remind them.

I really enjoy reading these forums, makes me think that something is moving after all. Keep it up and hopefully Red, and the competition, will deliver wonderfull new, cheaper and lighter tools we can tell our stories with.