Is T2.0 lens worth it?

[Christoffer Glans]

7-56mm, which would be about the same field of view as 27-216mm on a full-frame 35mm still camera.

How do you calculate that?

 

[Eryc Tramonn]

"I would gladly burn in HELL if that was possible...
Carefull what you wish for. LOL

I second that.

 

[Chris Newman]

Ramping aperture

Ramping aperture

I know this is blasphemy, but I actually think a ramping aperture is a good thing. Consider for a moment Scarlet with a lens that ramps from T2.0 on the wide end to T2.8 on the tele end. The aperture at the tele end tends to be most of what determines the size/weight/cost, so you get the T2.0 on the wide end nearly for free. If you don't want the ramping, you can just set the lens to 2.8, and maybe there could be a switch to prevent you from setting it below 2.8.

T2.8 is plenty to blur the background at the tele end; the wide and medium focal lengths are where it is hard to limit the depth of field, and we would want the T2.0. Plus, for me, I think about 80% of my shooting is in first half of the zoom range (27-108mm equiv.) anyway.

 

[Christoffer Glans]

75% of my footage is 17 - 40mm
It's a very good wide range.

But another thing that is very very important is the close up ratio.
How close can we get to the subject? Can we film the eye of a person, filling the frame with that eye?

 

[Chris Newman]

How do you calculate that?

In Brook Willard's FAQ in the Red One forum, he compares formats (there is a nice graphic, if you haven't seen it). He says 2/3" is 10.4x5.9mm, and I happen to know that full-frame 35mm is 36x24mm, so the crop factor is about 3.5 or 4, so to keep the same angle of view (using similar triangles from geometry), you would multiply or divide the focal length by this number. I guessed Scarlets starting equivalent focal length to be around 27mm because it is a bit wider than most cameras in its class, which is what most people seem to be asking for. Much wider than this and the lens would start to get a lot more expensive.

 

[Peter Majtan]

I thought Hell froze over when Jim started shipping the RED One... :biggrin:

That's what I thought... :biggrin:

 

[Peter Majtan]

In Brook Willard's FAQ in the Red One forum, he compares formats (there is a nice graphic, if you haven't seen it). He says 2/3" is 10.4x5.9mm, and I happen to know that full-frame 35mm is 36x24mm, so the crop factor is about 3.5 or 4, so to keep the same angle of view (using similar triangles from geometry), you would multiply or divide the focal length by this number. I guessed Scarlets starting equivalent focal length to be around 27mm because it is a bit wider than most cameras in its class, which is what most people seem to be asking for. Much wider than this and the lens would start to get a lot more expensive.

You lost it couple of post above. Please do not mix 35mm STILL with 35mm CINE. The RED's S35 sensor is actually "only" 24.4mm x 13.7mm - half of your measurement... I am not going to even get to the other issues - way too tired after pulling all-nighter. Going to get couple of hours sleep... :calm:

 

[Christoffer Glans]

Do people consider the fact that there are lenses that adapt to cropfactors?
Like EF-S lenses by Canon that adapt to the DSLR's with a cropfactor of 1.6 making a 20mm lens... 20mm.

So, if a lens is developed specific for the Scarlet, might it not be possible to make it 15 - 120mm without any cropfactor?
That way we don't need to go down to extremes like 7mm. If you want extreme fish eye, there's good adapters for that, but for a good range I'd suggest 15 - 120mm for the 8x lens.

As earlier said, it would be possible to make it 2.0 at it's widest and 2.8 on the tele end.

All in all, 15 - 120mm would be a really good range. 20 - 160mm works too, but 20mm or less on the wide end is a must in my view.

 

[Chris Newman]

Glazarus,

I wish I could draw pictures to help explain this. For a particular camera, we choose a lens based on angle of view rather than focal length. Depending on the format of the camera, the angle of view that we want will end up being different focal lengths. You said that 15mm is good for the wide end. I'm guessing that means you are used to working with DSLRs, Red One, or 35mm cinema. On a camera with a smaller sensor, everything gets smaller, including the distance from the sensor to the lens (focal length), so 7mm is a good wide angle for this format. It is not "extreme" or fish eye, because we are only capturing a small rectangle of the image. Outside of that rectangle, we don't care if the image gets dark. On a larger camera, 7mm would be extreme because the image has to be good across a larger rectangle.

I don't know if I'm helping, but keep asking questions.

 

[Chris Newman]

Peter,

full-frame 35mm still format is commonly used to compare equivalent focal length fields of view, and to be sure, I explicitly said "full frame 35mm still". You are correct, Red One has a crop factor of about 1.6 vs. full-frame 35mm still (similar to a DSLR), so the crop factor between Scarlet and Red One is about 2.3 (so the 7-56mm Scarlet lens would be equivalent to 16-128mm on Red One or a DSLR).

If there is anything inaccurate in any of my calculations or statements, please let me know (after you get some sleep of course).

(I'm hoping we can constructively trade ideas, admit if we are ever wrong, and learn from each other without getting defensive or flaming each other.)

 

[Christoffer Glans]

Glazarus,

I wish I could draw pictures to help explain this. For a particular camera, we choose a lens based on angle of view rather than focal length. Depending on the format of the camera, the angle of view that we want will end up being different focal lengths. You said that 15mm is good for the wide end. I'm guessing that means you are used to working with DSLRs, Red One, or 35mm cinema. On a camera with a smaller sensor, everything gets smaller, including the distance from the sensor to the lens (focal length), so 7mm is a good wide angle for this format. It is not "extreme" or fish eye, because we are only capturing a small rectangle of the image. Outside of that rectangle, we don't care if the image gets dark. On a larger camera, 7mm would be extreme because the image has to be good across a larger rectangle.

I don't know if I'm helping, but keep asking questions.

I'm using 1.6crop DSLR's, 35mm still, 1/3 cameras, but I also use mini35 adapters which makes a 15mm lens a 15mm lens on any camera.
15mm at it's actual focal length based on a 35mm image is the angle of view I'm talking about.

7mm can create other problems with aparture and stuff...

Still, you can use EF-S on a 1.6 crop Canon DSLR camera to make 15mm equal to 15mm. If Scarlet use a lens that is specific for the camera, it should be made with the cropfactor counted in so that 15mm is equal to 15mm on a 35mm fullframe.
Reason that Red One is 1.6 cropped is because it uses interchangeable lenses. I don't know if anyone with the Birger Canon EOS mount tested an EF-S lens or not, but those should remove the 1.6 cropfactor when calculating focal lengths. Nikon has such lenses too I guess.

So, if the lens is created with the cropfactor in mind, then it's no big deal making a 15 - 120mm what it is, without having to go down to 7mm to reduce the result of the cropfactor.

 

[Chris Newman]

another thing that is very very important is the close up ratio.

As I said before, all else being equal, everything gets smaller when you go to a smaller format, and that includes the distance to the subject, so smaller format cameras tend to have better macro capabilities. However, a longer zoom counteracts this effect. This is one reason that larger formats don't have zoom ratios as long. 8x is not a huge zoom ratio, so I would expect that Scarlet will be quite good at close focusing.

 

[Alsone]

There still seems to be confusion about equivalent focal lengths. I would expect Scarlet's lens to be about 7-56mm, which would be about the same field of view as 27-216mm on a full-frame 35mm still camera. I think a 216mm telephoto is a enough for most things

OK maybe its time to demonstrate just how useless a small focal range is for sport and thus general consumer / prosumer usage been as around 90mm or 120mm or 240mm have been mentioned on here as possible long end maximums.


This clip is shot using a 120mm lens at full zoom:

http://www.vimeo.com/957092


The surfer is like an ant and this is taken from a headland side on to the beach. The distance to the beach is probably 3 times the distance to the surfer from the side position. So thats at least 360mm just to get this ant like view from the beach.

As for teleconvertors, I've commented elsewhere about these but in summary they degrade image quality, they double the minimum aperture from f2.8 to f5.6 (2x convertor) and they increase the DOF as a result.

Even so, to get this frame filling might take around 600mm from where I was stood or double that from the beach so even with a teleconvertor added, a 600mm + unconverted lens is needed for this shot (teleconverted to 1200mm + from the beach).

Think this is unusual, ever been to a grand prix? The stands look close on television but the real distance to the track is vast. Ever tried to video jets at an airshow in an aerial display? - if so you got ants again. What about that concert where you were 100 yards back from the stage. Windsurfers, boats at sea, Kayakers (out in the river), mountain climers on a face, hang gliders etc etc.

Sports footage isn't possible with less than 500mm to 600mm at the long end unconverted and most consumers / serious amateurs shoot sports as their subjects not studio dramas / sit coms.

If Red are serious about making the Scarlett a mass market camera, they need to address this issue with a lens with a focal length similar to that on the XH-A1.

 

[Chris Newman]

Ok, this would be a reason to want interchangeable lenses, but a lens, tripod, and head good enough for professional results at these events would cost many times what Scarlet costs. I think this is beyond Scarlet's class of videography. I think Scarlet can be a lot of things to a lot of people, but even I think this is a job for a high-end setup.

 

[Peter Majtan]

Peter,

full-frame 35mm still format is commonly used to compare equivalent focal length fields of view, and to be sure, I explicitly said "full frame 35mm still". You are correct, Red One has a crop factor of about 1.6 vs. full-frame 35mm still (similar to a DSLR), so the crop factor between Scarlet and Red One is about 2.3 (so the 7-56mm Scarlet lens would be equivalent to 16-128mm on Red One or a DSLR).

If there is anything inaccurate in any of my calculations or statements, please let me know (after you get some sleep of course).

(I'm hoping we can constructively trade ideas, admit if we are ever wrong, and learn from each other without getting defensive or flaming each other.)

Back from sleep...

First of all You have said "I happen to know that full-frame 35mm is 36x24mm". Nowhere in there is the word STILL. Now this is a REDUSER forum, not Canon, not Nikon, not any other 35mm STILL photography forum.

When You refer here to "full-frame 35 mm" sensor - everyone assumes You are talking cine sensor. Equally referring to RED ONE as having 1.6 crop factor is very misleading (yet true compared to still 35 mm). All the 35mm cinema lenses works just fine with RED ONE without any crop. Also all the 2/3" lenses we were discussing here are video lenses and when used with Scarlet's 2/3" sensor - no cropping will occur. We are not discussing converting Scarlet to interchangeable lens format. Not at all - there are plenty of other thread poking the sleeping dragon on that. Everyone needs to realize that Scarlet is going to have FIXED lens. All the guys here were simply referring to the fact that "if such a lens would have been fixed into Scarlet what would happen".

And I am not getting defensive or flaming at You - only pointing things out that should be clarified or corrected... No one is perfect - we all make mistakes...

It was precisely this kind of misleading information that led to the "little out of the topic" discussion as to how Scarlet would crop what ever lens, bla bla bla.

If Scarlet is going to have 10 - 80 mm lens it is going to be 10 - 80 mm. If it's going to have 20 - 160 mm it is going to be 20 - 160 mm. No cropping can occur with fixed lens camera.

Cropping only occurs when you start stuffing lenses on a interchangeable lens camera that do not belong there - such as 35mm STILL lenses onto a Red One.

So everyone please lets stop talking about the "cropping" issue as there isn't any with Scarlet. Period.

I, for one, am for a very wide angle zoom, as it is much easier to add high quality tele-photo adapter to a fixed lens, then it is to add wide-angle adapter. This would serve ALL markets...

 

[Alsone]

Ok, this would be a reason to want interchangeable lenses, but a lens, tripod, and head good enough for professional results at these events would cost many times what Scarlet costs. I think this is beyond Scarlet's class of videography. I think Scarlet can be a lot of things to a lot of people, but even I think this is a job for a high-end setup.

This to me is a reason to mirror what Canon did with the lens on XH-A1, no need for interchangeability just a wide focal length 32-650mm in a high quality fluorite lens that kept everyone happy.

I'd even be happy for a little more at the wide end to satisfy studio shooters provided the zoom end was still in the 500-600mm bracket.

Also, why is this "high end" usage? Realise that most consumers / serious amateurs / non wedding based semi pros shoot sports and these are people who want a complete camera out of the box as they can't afford additonal lenses.

@ Peter, there's no teleconvertor made thats going to give 1000mm + after conversion from an 80mm base lens and if there was the faults / aberations revealed by it would be horrific. Hence the reason why such a long end is needed pre conversion and hence another reason why such a long lens is also needed, to prevent in most circumstances the need for any conversion where possible as even 2x degrades the image.

 

[Chris Newman]

I brought up crop factors because a lot of people are not used to thinking about 2/3" focal lengths (e.g., 7mm is wide, but not fish-eye, and 50mm is telephoto). Perhaps I only added to the confusion.

I'm with you on wanting a very wide angle.

 

[chuck colburn]

Afocal converters (not teleextenders) do not, for all pratical reasons, affect stop. And if the Scarlet is going to be a fixed lens camera these are the only type units that one could use.

 

[Peter Majtan]

Peter, there's no teleconvertor made thats going to give 1000mm + after conversion from an 80mm base lens and if there was the faults / aberations revealed by it would be horrific. Hence the reason why such a long end is needed pre conversion and hence another reason why such a long lens is also needed, to prevent in most circumstances the need for any conversion where possible as even 2x degrades the image.

If You regularly have a need for 1000mm lens - Scarlet is not for You my friend... You better of using Canon's XL-H series with the canon XL-to-EF adapter and any Canon L-series 35mm still lenses. You will get around 8.8x (in 16:9) zoom factor - so the great EF 70-200 f/2.8L zoom lens (http://www.bhphotovideo.com/c/product/234444-USA/Canon_7042A002_70_200mm_f_2_8L_IS_USM.html) will give You zoom range from 616 to 1760 mm!!! And all the ants are gone...

 

[Christoffer Glans]

If it's going to have 20 - 160 mm it is going to be 20 - 160 mm. No cropping can occur with fixed lens camera.

Which was exactly my point about the Canon EF-S lenses. If there is cropping when using a normal 35mm lens on a 1.6 cropped sensor, then with an EF-S there isn't any. So, a fixed lens is sure to be made with the sensor in mind and therefor 20mm will equal 20mm, nothing else.

My only hopes and my only plead to the Red team is that they really understand the need for a good wide range. In HD you don't need a close up to see an actors reaction, you can have a whole scene with a wide lens and let it play out. Cinema vs TV has primary been about using wideshots more then close ups. And this is digital cinema, right?

So, I pray for a really good wide to tele range; 15 - 120mm