I call Hot Rod Cameras Bluff with a $10,000 Bet (for Sharpest PL RF for Komodo)

[GrahamClark]

Am I getting this right if I say that you, Graham claim that your mount which, if I understand Iylas comment above correctly, is a mount that is not possible to shim is more precisely made than Iylas mount, which is a mount that can be shimmed?

Just to be clear, what ever the tolerance a mount is made to does not mean jack shit if it can not be shimmed.


Also Graham, as your mount is bolted down to a dowtail or something fixated only to the bottom of the camera for support you can not really compare it to Kippertie or vocas as Komodo cameras comes with different paint thickness and other oddities specific for each camera. So when fixating the mount as you do, you are likely to put stress on the RF mount and by doing so get an uneven flange distance. KipperTie for example does it differently with their chinstrap that use 4 mounting screws and if mounted correctly to the camera, as descibed on their web page, their chinstrap will give good suport for the lens mount without adding any stress to the mount in a way which a single mount point suport never can, no matter how precise the mount is made, again all individual cameras are made slightly different.

Bjorn,

100% 316 shim set, just like Cooke's shim set.

We use the same shim system so you can to +/- up or down, stainless steel as well.

The crux of it is simple – our PL RF Komodo was designed to be critically sharp out of the box, no need to add shims if your PL glass is collimated to spec.

Basically it reduces 3 variables of the equation down to 1.

The result is the camera resolves sharper than you thought possible.

It's easier to see side-by-side comparisons of results from filmmakers than for me to say anything about what could be, I agree to that.

 

[GrahamClark]

I'm confused. This seems like two different use cases.

We're comparing a mount with no shims to a mount with shims?

Phil do you want to speak to this elephant in the room before going into a test?

Seems like the mount with no shims may be fractionally more accurate if put on a matching camera (I could see how if it was desiged specifically for Komodo this could be so if RED's tolerances are very tight and they don't change manufacturing processes), but:

- do filmmakers really need more accuracy than shims provide in real-world use?

- is it worth giving up the possibility of shimming in the future?

RF mount should be around for a loooong time. If RED makes a Komodo 2 or we want to put it on a Canon cinema camera (seems like nice ones are coming), I'm guessing we'd need to buy another adapter? That said, I could see that many Komodo folks would sell their PL mount with their camera... but also that means when every new camera comes out you have to wait for the mount guys to manufacture you a mount, whereas the guys with the shimmable mount can just start playing.

Have I got this correct, technically?

So I guess my next question would be what the real world advantages of giving up shims are.

I obviously trust shims... because they work, so you can see I'm a bit confused why make something expensive without shims. What am I missing?

Bruce Allen
www.bruceallen.tv

Bruce, what everyone is missing is the context around the products, as I didn't provide any as I should have in the first post, you can see product page with more details here:

www.PL2RF.com (nothing to buy, only information)

SHIMS: 100%, will never do away with shims, until I make a user-adjustable backfocus lens mount, but even then I consider there still a use-case for a shim system
OBJECTIVE: Critically sharp out of the box for Komodo

Then you can shim all day long, up or down.

I'm a newcomer to cinema, and there's a lot for me to learn, and I'm excited to learn as much as I can.

My area of expertise is very narrow: optical glass and CNC machining, nothing else.

Within those narrow confines I can guarantee you that the PL RF mounts on the market right now are "night and day" different when it comes to sharpness due to the fact that they're PL to "RF", and Canon has 3 different flange depths for 3 different cameras... photographers don't care, lenses with hard stop infinity, they care.

Can you shim it, eyeball a chart and get close? Of course.

But the result of what we're making is like if you take the thinnest shim, divide it by 4.

Calibrating CNC machines often uses laser calibration to achieve tolerances much higher (thinner) than cinema shims, we've taken that kind of technology to PL sharpness, which provides us a numerical output for flange depth, the closer to spec the sharper it is.

And just like CNC equipment, we print a "certificate of calibration" which corresponds to the serial # of the unit calibrated.

As for other cameras, I'm sure in the future we can make a PL RF for all RF cameras, and have the shims marked "R5, "R", "C70" so you just insert it and you're all set to go.

But this PL RF is only for Komodo, for other practical reasons I won't dive into yet.

Komodo only, nothing else.

 

[GrahamClark]

why do you need shims if the camera has sensor adjustment? does Komodo have sensor adjustment?

Right now there's 3 moving targets, once camera and lens mount are dialed in, only 1 moving target – PL lens spec.

For DSMC2, if the sensor is factory set, so if the lens mount is calibrated like CNC machines are, the only moving target left is PL glass.

Movable sensor – this is great invention by RED.

The DSMC2 PL mount is incredibly precise to PL spec. We're not outdoing RED at their own mounts, but we're on par.

If the Komodo had a PL RF mount with equivalent PL flange depth accuracy, we wouldn't be having this conversation about Komodo mounts, and there wouldn't be an opening for a "critically sharp out of the box" product, like what you come to expect on a DSMC2.

So if PL flange accuracy can be solved at the mount level (shimmable or user adjustable backfocus etc.) the equation can be simplified to collimating the PL Lens, and the sensor can remain static.

RED did their job with making the camera to spec, in my opinion it's up to the accessory manufacturers to make to spec.

When filmmakers post their before / after shots of some really great PL RF adapters on the market, the objective I think will be a bit more clear.

 

[GrahamClark]

This is a fun read and I love the idea of a "SHARPNESS" sabers at dawn kind of duel. How are we defining "SHARPNESS" BTW - resolution + contrast ? Is there a number that comes out at the end, or is it 'Bro your shit is the most "SHARP".

Should we instead be talking about the AR coating, thickness and spectral transmittiance of the behind the lens ND filter ? It would seem to have MUCH more effect to more people than very slight FFD variances, shimmed or not. ( OK I prefer shims )

Matt Uhry
vimeo.com/mattuhry

Yes, color neutrality and light transmission for ND and CPL is where it's at, that's the real objective, that's where all the fun is at

But critical sharpness on Komodo however IS important, and easy.

Maybe you're inferring to Hot Rod Cameras claim that "Breakthrough Filters transmission is subpar", let's talk optical performance on a different thread.

This one is purely "Critical Sharpness PL Komodo" out of the box.

 

[GrahamClark]

Illya Friedman

Graham,

...

"I don't know you, so to proceed let's establish an element of trust. You are the challenger brand in this space, you have everything to gain by going up against the original and still best PL mount adapter ever made, and nothing but a $10,000 charitable donation to lose."

You're the one who bet you'd beat our mount, I'm simply calling your bluff and agreeing to that bet.

When you falsely claimed our spectral neutrality was not what we said, and saying something about an interferometer, and now this all lead me to ask myself "when do false claims prevail over scientific results?"

"You mention Instagram, in Phill's post comments a 3rd party decided to take you to task for your claim, to which you responded rather rudely and accused of being connected to KipperTie. I don't know that person, but I have to say they made exactly the right point."

I didn't claim you of being connected to KipperTie, someone else did.

To be honest I don't know of either of your companies, what you do or make, except that you have a camera store, which is great, more stores like yours instead of Amazon and B&H the better.

As you said, I'm an outsider in cinema. I agree with you.

"Which is, the distance between sensor position and camera flange depth is 100% the largest variable in the equation, especially when you have multiple manufacturers of cameras building to that same standard."

Komodo only – other cameras – irrelevant.

"... it seems you are claimig that your knock-off, non-adjustable mount "

www.PL2RF.com – critically sharp out of box yes, shimmable yes!

of course shimmable, my mistake for not linking the product page (nothing to buy) for product detail

"This will be fun, I can't wait to see what you write next."

A fun bet about Komodo sharpness, I consider it just that – fun and amusing. The result is unknown, that's what makes it fun

I don't take what you said about our lens mount personally, as an industrial designer it's more of a sport, it's fun, so I'm sure you're just as well intentioned and don't mean any ill intentions. As you said, "This will be fun"

False claims about color neutrality is what's coming, I'm looking forward to that one next, in a separate thread, a separate bet.

 

[Jacek Zakowicz]

IMO it boils down to two issues as far as the camera body is concerned. Lenses are a separate issue since they don't have(unlike dedicated video camera lenses) adjustable back focus.
1. How to measure , determine flange depth on the camera body reliably so the mount can be shimmed accordingly.
2. How to measure reliably, determine, address the thermal expansion coefficient of the sensor location since the camera temperature varies 40-60-80 degrees throughout the day. Adjustable back focus lenses on video cameras addressed that issue quite well in the past. Adjustable sensor position addressed that issue on REDONE, DSMC/2 ARRI, Sony etc. Since Komodo does not have that feature and lenses can't compensate with adjustable back focus the mounts should step up...
I might add that the ever increasing resolution and, consequently, smaller pixels do not help in the precision department...
That's theory because in practice prime lenses "don't care " much about back focus unless they miss infinity. Still camera manufacturers solved that long time ago. They just set both the flange depth and back focus short to assure infinity is always obtainable. They realized a while back (circa 1985) the with auto focusing nobody will bother to check the focus scale calibration. They also realized that for minimum focus the error would have to be HUGE to matter so no issues on that end either for all practical purposes. That's how we got through today- massive technical issues with minimal practical consequences- human ingenuity at its best haha ;-)*
* two notable exceptions
- Zom lenses (parfocal, fast/wide especially) in zooming sequences
-anamorphic lenses
in both above instances adequate precision is a must- both for the flange depth and the back focus...

 

[GrahamClark]

IMO it boils down to two issues as far as the camera body is concerned. Lenses are a separate issue since they don't have(unlike dedicated video camera lenses) adjustable back focus.
1. How to measure , determine flange depth on the camera body reliably so the mount can be shimmed accordingly.
2. How to measure reliably, determine, address the thermal expansion coefficient of the sensor location since the camera...

To have a discussion about the "how" I would recommend we create a technical thread.

A simpler more practical approach might be to simply examine the results between mounts.

Objective: shoot hard stop infinity focus between two mounts, compare which is more critically sharp.

Here is one such example by filmmaker Matt Devino:

https://www.dropbox.com/s/6c9upzgjvj4ynp8/Breakthrough PL vs Tilta PL on Komodo.jpeg?dl=1 (1.1mb 3382x1212)

 

[Jacek Zakowicz]

That's nice.
Now in case the image is softer:
How do you know if you need to add or subtract shim? How thick is the shim supposed to be? Are you planning to do that by trial and error?
BTW that is not your problem Graham as long as you provide a way to correct it i.e. shimming...

 

[Björn Benckert]

I

Bjorn,

100% 316 shim set, just like Cooke's shim set.

We use the same shim system so you can to +/- up or down, stainless steel as well.

The crux of it is simple – our PL RF Komodo was designed to be critically sharp out of the box, no need to add shims if your PL glass is collimated to spec.

Basically it reduces 3 variables of the equation down to 1.

The result is the camera resolves sharper than you thought possible.

It's easier to see side-by-side comparisons of results from filmmakers than for me to say anything about what could be, I agree to that.

Komodo can not be easily backfocus adjusted. That does not mean all komodos have correct backfocus.

I’m no expert in this field but I made and sold somthing like 100 pl mounts the year the 7d came out. Yes before Hot rod PL mount was a thing. They bought one from us, said it was shit and made more professional 7d conversions after that.

But in this hole ordeal it seams like you Graham are missing one important point. Two dsmc cameras likly does not have the same backfocus of the shelf when bought from red. Most even half serious rentalhouses has collemators, projectors lens and camera techs to check and adjust backfocus on every camera and lens set, usually its done prior every big project. My monstro had backfocus corrected atleast 20 times. Backfocus on cameras drift over time. Eapecially DSMC cameras.

Dsmc is trim screw adjustable. Red was even selling thier colimation / calibrating backfocus tool for PL mounts before called red focus.

The norm is that the AC put the camera in a collimator together with the rental house lens tech to have it checked and corrected. Just as the lenses to be used are checked and corrected / chimmed correctly before every large project.


Now reds backfocus adjustment for dsmc2 was not so good and rental houses did not really like em. So for the ranger line of cameras red ditched the idea and instead went with a fixed mounted sensor and a pl mount with shims.

Back focus also change with working temp. If you are in the desert your backfocus might be dead on... then when in the snow and cold on a mountain top... likly its likly then quite off for the same camera. Reds did not make mounts in titanium and magnesium just for fun its simply so that those metals does not expand and contract as much as aluminum when temperature change.

You should not take for granted that two fresh out of the box komodos has the right or the same flange distance. RF mount is built for lenses where it does not realy matter. So if you want it right you need to check and adjust your pl mount.

the red focus is easily checked and corrected and if you have such you can, easily use in the field to make sure all kameras on set atleast got the same bf every now and then and if not correct them.

How exact the mount is made from scratch does not mean jack shit if the camera aint correct, and usually its not.

 

[Björn Benckert]

If you dont have one get one. https://www.adorama.com/rd7900149.html

 

[Jacek Zakowicz]

Bjorn It is not his problem that the camera is not correct. His responsibiliy is to sell mount that is square and 32mm flange to flange (or less) and supply the shims for corrections. The purchaser assumes the responsibility to set the flange depth on their camera.
I do see that Graham erroneously claims the responsibility for something he will not have any control over- the flange depth of Komodo with his PL adapter. That could be interpreted as false advertising. I don't think that's the case but that he is just over enthusiastic all the while not having enough experience in this matter....

 

[GrahamClark]

That's nice.
Now in case the image is softer:
How do you know if you need to add or subtract shim? How thick is the shim supposed to be? Are you planning to do that by trial and error?
BTW that is not your problem Graham as long as you provide a way to correct it i.e. shimming...

The same way we calibrate CNC machines, precisely and accurately.

And then we machine it to spec, on the calibrated CNC machine

 

[GrahamClark]

Dsmc is trim screw adjustable. Red was even selling thier colimation / calibrating backfocus tool for PL mounts before called red focus.

This is about Komodo only.

We can make a separate thread about the DSMC2 DFM like the one I sent to Mark Toia.

For Komodo better to look at side-by-side results between lens mounts than talking about it, in my opinion.

The difference is incredible.

 

[GrahamClark]

Bjorn It is not his problem that the camera is not correct. His responsibiliy is to sell mount that is square and 32mm flange to flange (or less) and supply the shims for corrections. The purchaser assumes the responsibility to set the flange depth on their camera.
I do see that Graham erroneously claims the responsibility for something he will not have any control over- the flange depth of Komodo with his PL adapter. That could be interpreted as false advertising. I don't think that's the case but that he is just over enthusiastic all the while not having enough experience in this matter....

The flange depth deviation between the R5 and the R and the C70 amount to slightly more than the largest shim made by Cooke.

Despite each of these camera models having flange depth deviations between the models (R5, R, C70), within each camera model I'm seeing indiscernible deviation of flange depth when measuring numerous units of the same model.

From what I've seen, the Komodo flange variance is in-line with the above camera models, non-existent, or you could say with a safety factory, take the thinnest shim and divided it by 2, even less than Canon – a non issue.

Perhaps because the DSMC2 sensor was movable, it creates the assumption that the Komodo must therefore also be a "moving target"?

If the thinnest shim divided by 2 is the answer to camera flange depth deviation, the Komodo is out of this equation, and we're back to lens and mount.

(DSMC2 is also out of the equation as movable sensor calibration can easily bring it into a micron level of accuracy, in-between the thinnest of shims)

 

[Jacek Zakowicz]

Graham, I don't even know where to start... how many samples have you measured? How did you measure? Was the internal temperature monitored? What was the actual flange depth variation in microns? What was the range of flange depth? There are probably half a dozen or more questions to answer before you make authoritative statement like that. In the technical realm we use numbers, they define the results with ultimate certainty...
BTW the thinnest Cooke shim I saw is .0005" are you saying that the flange depth of Komodo variation range is .00025"? That's nonsense- no assembly containing more than one part can hold that- not to mention dozens of parts made of different materials across 60+ degrees of temperature range...you can compensate with the shim of course- but I have never seen that kind of precision .... calibrating offset on a CNC machine where all variables are known is a wrong example IMO

 

[GrahamClark]

Graham, I don't even know where to start... What was the actual flange depth variation in microns? What was the range of flange depth? There are probably half a dozen or more questions to answer before you make authoritative statement like that. In the technical realm we use numbers, they define the results with ultimate certainty...
BTW the thinnest Cooke shim I saw is .0005" are you saying that the flange depth of Komodo variation range is .00025"? That's nonsense- no assembly containing more than one part can hold that- not to mention dozens of parts made of different materials across 60+ degrees of temperature range...

How do you know if you need to add or subtract shim? How thick is the shim supposed to be? Are you planning to do that by trial and error?

1. You're missing a zero, zeros matter.
2. Micron level, yes
3. Take Cook'e thinnest shim, divide by 2
4. Instead of veering off track let's jump into side-by-side images and go from there.

Komodo flange depth is for a different thread

This thread is about "critically sharp PL Komodo out of the box" not "does the Komodo flange depth deviate because DSMC2 has a movable sensor?"

And to that end I think we can summarize results with side-by-sides without much back and forth as to "how" or "why", rather "what is".

 

[Dan Kanes]

I would recommend one of these:

https://www.pure4c.de/accessories/measuring-device/field-collimator/549/denz-new-fdc-light?c=221

Worth every penny. Once you get one, you probably won't look back.

 

[Peter Choi]

Following

 

[Björn Benckert]

This is about Komodo only.

We can make a separate thread about the DSMC2 DFM like the one I sent to Mark Toia.

For Komodo better to look at side-by-side results between lens mounts than talking about it, in my opinion.

The difference is incredible.

Graham,

Listen to Jacek he knows his shit.

As I see it you wrote enough in this thread to reveal that you know little or nothing about how these things work.

Sure, Your CNC machines might be extremely correct, your mount might be made perfect to microns spec. But that is pretty much of zero relevance when the main feature of the adapter it self is supposed to be the adjustable variable that correct the flange distance of what ever camera its mounted to. And yes the cameras flange distance differs and that is a fact not just for every other camera but also for all komodo cameras.

What is important for a good mount adapter is and yes, lets talk only about komodo PL adapters to hatch out other oddities.

1. The mount adapter is flat / has no deviation or skew. Here of course low tolerance / good machining is of importance. But making something very flat is not directly space science when it comes to tooling.

2. The mount adapter should be sold with a flange distance that is less than needed and comes with shims or similar adjustment capabilities so it can have added or removed shims to allow for adjustment so it works with any camera that has the given native mount. For RF mount cameras the variation is quite big as RF mounts are made for still glas where this is not important, as Jacek and others stated above.
Some of the RF cameras even have the mount ring seated in plastic with 4 little threaded screws, like Canon for example, they dont give shit about backfocus. But yes, we stick to Komodo. Simply put, two Komodos next to each other will differ in BF distance and if they don´t... then they will later when they are broken in.

3. Bolt down / locking mechanism. The RF mount standard is shit, in the regard that it´s not sturdy enough for big cinema zooms etc, it flex and does not hold enough rigidity to hold the mount adapter fixed in a normal camera working scenario. So the mount needs to be bolted down. Now, Kipper tie and Vocas has solutions for this matter where they use 6 mount points, the RF mount and the 4 screw holes on the side of the Komodo and one into the dovetail. Both systems allows for the mount to be seated in the RF mount and then you tighten the side screws without putting much force / stress onto the actual mount. Which is not perfect but better than most.

Your breaktrough mount on the otherhand only have two mounting points and that will put more force / stress on the mount. Especially as your one mountingbolt goes down into the dovetail. Likly when that bolt is tightened down it will pull force on the mount stand and create a "swing shift" effect to the image plane, basically offset the mount so there is a different flange distance between top and bottom of the frame. If you where into the microns you would build your mount differently, more like kippertie chinstrap or Vocas mount.

It´s a known fact that the komodos comes in different dimensions, For example the colored komodos got thicker and more uneven paint than the black ones. The rumor is that the colored ones where Painted by the man himself, in his garage during lock down and the black ones have a thinner coat of paint as they are factory painted... Now, do you sell your mount stand that bolts down to the dovetail with shim as well or how do you adapt it to the difference in camera height between hand painted colored komodos and black komodos? surely if you done your testing you know that there is a difference between the two.


Jacek, and the guys at hotrod has fiddled more with cameras than most. My advice would be to listen and learn from them.

 

[John Brawley]

Graham I think you need to take a moment.

If your product isn’t able to be shimmed to each individual camera then you’re dead in the water.

The hyperbolic claims about Cooke lens shims and degrees of precision are just making this all seem comical.

You’re pitching a product in a market where you admit you’re new.

You appear to be making a fundamental design mistake claiming to be sharper out of the box, a meaningless marketing phrase that will not sell any units and only make you seem naive.

If your product does something that we don’t compute or understand then you’re not doing a very good job of explaining it.

After reading this thread I still do not understand what your reference to Cooke lenses shims even means.

You make a mount Adaptor ?

Can it be adjusted or shimmed ? If the answe is no then your product is a dud

If your answer is to shim the lens itself using Cooke lens shims then your product is a dud.

If I have that wrong then you’re not doing a good job of communicating or marketing.

JB