Red Scarlet-X

[Drew 0]

Thanks for the "geek" explanation Paul. I tried to follow Alex's domes without drones philosophy. So glad someone else took up the mantle of precise answers!

 

I do hope people have an understanding of what the various modes are about on a scarlet/epic/r1. At 5k/4k, you get the full sensor, 3k=2.16x crop, 2k/1080p=3.24x crop. So basically if you want to shoot higher fps, you have to get a super duper wide lens like a fisheye and you still won't be able to get wide angle look at less than 3k. And if you think the 120fps @ 1k is going to be awesome, it's 6.4x crop.

 

 

Here's a visualized version:

 

 

Thanks to Phil Holland for allowing people to understand the implications.

 

Cine lenses would plain suck for anything less than 4k. And HDRX isn't usable until 3k as clips. For stills on the other hand, it looks pretty darn good, but ISO performance isn't going to be anywhere close to the 1DX. Personally, I think every Scarlet user will want the Canon EF8-15 for underwater!

[SimonSpear 65]

I thought you'd joined the plain English campaign Drew as I can generally understand what you are talking about these days!

 

The 8-15L is a great lens which could be an excellent choice but I'd like to see how bad the distortion is at 3k and 2k from a fisheye before I spend the cash on it. Personally I don't have the cash for any extra lenses right now but I do have a Samyang 8mm that I can try out which might give an idea.

[DeanB 19]

Personally, I think every Scarlet user will want the Canon EF8-15 for underwater!

 

A snip at just over £1000 ... Well compared to the other mega bucks lenses mentioned

 

Dean

[DeanB 19]

Personally I don't have the cash for any extra lenses right now but I do have a Samyang 8mm that I can try out which might give an idea.

 

You cheapskate Spear!!! Get a bloody decent lens or you can keep that Scarlet to yourself!!!

 

Dean

[Drew 0]

I thought you'd joined the plain English campaign Drew as I can generally understand what you are talking about these days!

 

The 8-15L is a great lens which could be an excellent choice but I'd like to see how bad the distortion is at 3k and 2k from a fisheye before I spend the cash on it. Personally I don't have the cash for any extra lenses right now but I do have a Samyang 8mm that I can try out which might give an idea.

 

Well wouldn't go as far as to say I'm typing english! I really don't think I was all that technical but apparently I guess I was!

 

The fisheye effect won't be as pronounced on the 16:9 format as the lens is still 3:2. For rectilinear, I'd choose the 8-16 Sigma. Even at 2k, it's 24mm which is very nice for WA. Even @ 1k, it's 51.2mm, which is useable for medium shots... if there is enough light for 120fps.

 

It's actually very easy to find out the look. Just download a pic at 9mm from the 8-15, then crop according to the format. Then adjust for the dome port shrinkage and you're there! How's that for english?

[MJvC 9]

What about the The Sigma 8-16mm F4.5-5.6 DC HSM for the 3K and 2K no fisheye distortion and you don't have to worry about corner sharpness as the image will be no where near the projected corners of the lens.

[Drew 0]

Opps the 8-16 is EFS... so you can't shoot 5k!

[jonny shaw 16]

Isn't the Canon fisheye F4 also? Wish they made a fast one.

 

John, if you are looking at PL lenses for underwater I would go for a Ruby 14-24, it is a Nikon rehoused but covers 5K full frame and is not a bad price at around $14K. Or you could go the cheap mans option and use a Opitek Nikon mount and just buy the Nikon version for $2K

 

I actually think that for underwater DSLR lenses are better, they are smaller, lighter and cheaper. PL lenses are great with no breathing and smooth as silk gearing, but you will need to spend another at least $3k on a Matte Box, 6K for a decent tripod to support the weight, 4x4 filters, rods, mounts etc etc, which all are expensive and heavy.

[Paul Kay 62]

Thanks for the "geek" explanation Paul. I tried to follow Alex's domes without drones philosophy. So glad someone else took up the mantle of precise answers!

I figure that if the problem makes sense then you are partway to dealing with it (rather than solving it). I was trying not to be too geeky. Optical quality matters but its pointless trying to achieve the impossible. Now if someone is interested in designing an aspheric dome.......

[JohnE 8]

Also, if you read Howard Hall's Lembeh report, his Red One actually melted, I suppose as heat built up in the housing during those super-long Lembeh dives. I've no idea if the more recent Reds run cooler, or whether housing design can somehow cater for it, but it's worth bearing in mind.

 

 

I spoke to Howard about this. The problem was poor contact on a battery / v-lock plate pin. That's what melted. It had nothing to do with the housing.

 

J-

[Nick Hope 151]

I spoke to Howard about this. The problem was poor contact on a battery / v-lock plate pin. That's what melted. It had nothing to do with the housing.

 

J-

Oh OK John, that's good to know. Hopefully it was a one-off problem, or that aspect of the camera has been improved with Epic/Scarlet.

[John Doe 0]

Well Done Paul Kay!

 

You've put into words what i sorta knew but could not explain clearly..............

 

"No matter how good the lens being used is, it still has the problems associated with shooting simple ports (lenses)."

 

And that's the point really. No matter how good the lens, even all the way up to Cooke lenses, we still shoot through a curved complex lenses that degrades the corners no matter what you do or which lens it is! So the exotic glass is going to have to stay topside and stick to the more common lenses for underwater.

 

I've been looking at the Dulcos 11-16mm and the Ruby 14-24mm. I still would like a Cooke but it really doesn't seem to make sense other then the satisfaction of owning a legend and playing around with it trying to kid myself that my footage is definitely better now........

 

It will be interesting to see what others do. I'm on the end of the Scarlet line so don't expect a camera for quite a long time. By then perhaps others will have taken the plunge and worked out whats working well.

 

Is there any chance that better domes will be developed? With the new age of RAW acquisition and such lens choices open to us now, is it realistic that domes can be improved any further?

 

J.D

[JohnE 8]

Well Done Paul Kay!

 

You've put into words what i sorta knew but could not explain clearly..............

 

"No matter how good the lens being used is, it still has the problems associated with shooting simple ports (lenses)."

 

And that's the point really. No matter how good the lens, even all the way up to Cooke lenses, we still shoot through a curved complex lenses that degrades the corners no matter what you do or which lens it is! So the exotic glass is going to have to stay topside and stick to the more common lenses for underwater.

 

I've been looking at the Dulcos 11-16mm and the Ruby 14-24mm. I still would like a Cooke but it really doesn't seem to make sense other then the satisfaction of owning a legend and playing around with it trying to kid myself that my footage is definitely better now........

 

It will be interesting to see what others do. I'm on the end of the Scarlet line so don't expect a camera for quite a long time. By then perhaps others will have taken the plunge and worked out whats working well.

 

Is there any chance that better domes will be developed? With the new age of RAW acquisition and such lens choices open to us now, is it realistic that domes can be improved any further?

 

J.D

 

A few comments:

 

* Bob Cranston succinctly said "The difference between $30K glass and $1K glass is 6 feet of seawater." Translation: cine lenses are better - even underwater - when you are close. But clarity, as we all know, degrades rapidly with distance in water.

 

* The previous point assumes good optical interaction between the lens and port. This is key, because it can vary greatly. Lenses that work great on land can be quite poor underwater behind a dome, and that includes cine lenses. Interestingly, one of the best wide angle performers behind a dome is the Tokina 10-17, a $600 lens.

 

* Lastly, underwater adaptive optics are indeed available. The Gates SWP44C Super Wide for the Sony EX1R is a good example. It has several optical elements (8, if memory serves) to provide a 100° FOV at wide and retains the entire zoom range of the camera. We also made a simpler one for the Zeiss DigiPrime 3.9 (one of those $30K+ lenses that performed poorly behind a dome). Underwater adaptive optics can be designed ostensibly for any lens, but with such a wide variety of lenses available for EPIC / Scarlet, which do you choose?

 

Good image quality is always king. Ports are very often overlooked as a key part of the equation. Said otherwise: "The best camera in the world can't make up for poor optics."

 

J-

[DeanB 19]

Thats why I'm adapting a £20k lens for my Sony Trv 950 ...

 

Dean

[John Doe 0]

John E - thanks for the insight!

 

Do you have a list of lenses that you have put behind your best dome that worked extremely well? I still prefer the cine approach if a choice lens can be made to perform.

 

What is the highest performing dome available? Are you saying you can custom work a dome to suit the chosen lens?

 

In general which cine lens do you recommend? or to put it another way ( so that no one can hold you to a "recommendation") which lenses have you seen housed in a Gates that are/were stellar performers?

 

I really appreciate your input in this discussion. (I'm sure many others do to!)

 

J.D

[Steve Douglas 16]

Would also like to know the quality differences, if any, between the Fathoms ports Gates used to sell and your current ports.

Steve

[Paul Kay 62]

What is the highest performing dome available? Are you saying you can custom work a dome to suit the chosen lens?

 

In general which cine lens do you recommend? or to put it another way ( so that no one can hold you to a "recommendation") which lenses have you seen housed in a Gates that are/were stellar performers?

Take a look at: http://www.underseacameras.com/Underseacam...Dome_Ports.html

 

An ideal underwater lens (for use behind a concentric dome port) would feature close focus, high optical performance at close focus, a first principal point for which the precise position is know and which does not move during focusing or zooming. It should also be in a position which can be precisely centred withing the dome port. I'd take some issue with the '6 feet of water' comment simply because whether visibility is good or not, corners remain a purely physical and optical problem and whist they can be optimised, they can't be completely corrected when using a concentric dome regardless of the lens being used behind them. Underwater optics such as those offered by Fathom are designed to operate with specific formats and lenses as far as I can find out and won't operate as well beyond their design intentions (or at least that is what I have been told by people who have tried them). There have been other lenses designed to correct dome ports for underwater use but as far as I have been able to research, these are either field-of-view-limited (not suitable for superwide use) or are designed for specific lenses only. All this said, some combinations of lenses and ports do give 'acceptable' results and whilst using the best lens possible will help minimise problems, it won't solve them. It would be interesting to get people to post the relevant data about their set-ups (lens being used, dome diameter, thickness and position, and so on) but this sounds like a fair amount of work and this data is not always so easy to measure. Even rough data might help though - lens/dome/results?

[Drew 0]

First of all, one has to remember that cine lenses are not designed for the same purpose as still lenses. Many older cine lenses don't focus close (usually in the 300+mm MFD range). So cine glass tend not to play well behind a dome. However, the newer lenses like the Ultra/Compact Primes, Cooke 5 etc do focus much closer which does help with working behind a dome. I am talking about wide angle lenses here.

 

I had long talks with 35mm film guys on different locations about the limitations of cine lenses behind a dome. That's why they shoot with flat ports sometimes, just to avoid the issues of domes and cine lenses.

[Paul Kay 62]

I am talking about wide angle lenses here.

A very good point. I personally would say that any lens with a field of view exceeding 90 degree is where the problems start when using a concentric dome. A lens with up to a 90 degree field of view can be corrected fairly well (depending on application and the particular lens - for example Canon's 20mm EF is difficult to get good corners when shooting FF digital above water so doesn't get any better underwater), beyond this it starts getting difficult without using a fisheye.

[jonny shaw 16]

After about 90 degrees the distortion and aberrations start to become a more of a problem too I believe

[Drew 0]

A very good point. I personally would say that any lens with a field of view exceeding 90 degree is where the problems start when using a concentric dome. A lens with up to a 90 degree field of view can be corrected fairly well (depending on application and the particular lens - for example Canon's 20mm EF is difficult to get good corners when shooting FF digital above water so doesn't get any better underwater), beyond this it starts getting difficult without using a fisheye.

 

I think that may be an issue of lens breathing? The FOV may have just shrunk to the point where the corners look great. Quite a few lenses perform like this including the Sigma 12-24, but it makes up for it by being so wide it still gives good FOV. That's something many people don't realize about their super wide zoom lenses. The lens isn't performing great. It's actually the poor lens breathing that allows corners to look great behind a dome. The problem is some lenses go the other way by actually being accurate at close focus and shrinking at you focus farther away.

 

That's one thing about the Zeiss Distagons for Canon/Nikon mounts. The breathing is minimized and they are very sharp corner to corner. That's why they are popular with the DSLR shooters and why Zeiss produced cine versions. I think the 21mm works very well behind a dome once you get the right focus gear. Only problem is I like stills more and AF is just faster than my left fingers and eyes.

[jonny shaw 16]

That's one thing about the Zeiss Distagons for Canon/Nikon mounts. The breathing is minimized and they are very sharp corner to corner. That's why they are popular with the DSLR shooters and why Zeiss produced cine versions. I think the 21mm works very well behind a dome once you get the right focus gear. Only problem is I like stills more and AF is just faster than my left fingers and eyes.

They are great lenses for the money, I actually reckon most people (including in the industry) would struggle to see the difference between them and Master Primes (although Mp's are 1.4) however I have heard a few people say that the 21mm isn't great and the 50 and 85 are brilliant. Also with the crop factor of Scarlet 21mm just won't be wide enough?

[Drew 0]

Well I'd like to see them fit a whale or a reef scene with a 85mm FOV in 15m viz!

[jonny shaw 16]

Well I'd like to see them fit a whale or a reef scene with a 85mm FOV in 15m viz!

 

Ha ha, didn't mean for underwater.

[John Doe 0]

Sounds like there is little love for cine lenses with the underwater crowd........ sounds like it is going to be a challenge to setup a cine lenses behind a dome. Seems a shame to use a cine above and something else below water but that's the way its looking to me.

 

So then how do we go about finding a nice lens for underwater use on the Red's? Possibly start a new thread on lens suggestions? Will that even get any traction?

 

It would be tragic to spend many $$$ on a cine lens then find its of little use underwater behind a dome.

 

J.D