serious 35mm adapter back-focus (collimation) errors

[Lenilenapi]

Well I'm glad i opened up this can of worms and we'll have to see how it all plays out, and whether getting these tools helps the manufacturers or it proves too much trouble. I do realize its a business.
Dennis is right in that when you start adding different mounts it all gets more complicated and lenses may not be adjusted perfectly.
My feeling is though, when you purchase, whatever you ordered should arrive properly set up. If you start changing mounts , well then you take your chances.

My own experience shows that even though I thought i had fixed my own collimation, and I did have quite a bit of background, I actually hadn't, because I couldn't find accurate info about whether my zooms should track or not.
It will be easier now that I know, and additions like the micro collimation have made fixing in the field a snap.

BTW Brian from Redrock emailed to say that they have been using collimators for a while now (no doubt after I had originally bought from them 2 years ago.)

Thanks folks. See some of you next week at NAB I hope.

Lenny

 

[twocik23]

"How do you figure 500-800 for costs of an adaptor? Curious."

Well Tim it depends on what's used (rough estimate)

Screen - $55.00 - $210.00
Achromat - $210.00
Material used (Aluminum & High Strength Static-Dissipative UHMW Polymer) - $90.00 - $180.00
Electronics - $30.00 - $65.00
Step down ring - $15.00 - $25.00
Mount - $40.00 - $85.00
Screws, glue, rods - $10.00 - $23.00
Tools to include - $2.00 - $5.00
Batteries - $2.49 - $4.00
Case with pluck foam - $35.00 - $50.00

"Collimator = 2 grand (roughly the sale of 1 1/2 adaptors (spread out over x number of adaptors over the life of the collimator).

Checking collimation = perhaps 2-3 minutes / adaptor (some will be less some more because of adjustment). Or say 20 / hour. At 20.00/hour for labor it would add 1 dollar / adaptor. At 10 an hour 2 dollars. Five an hour would be 4 dollars."

I'm speaking in general guys, not saying this isn't something you should use.

If you're looking at it that way yes, but you're forgetting about the cost of materials and labor to operate the machines.

Making the shell to an adapter can take 20 - 80 mins CNC, or can take up to 4 - 6 hours manually. There's alot that really goes into machining that even I didn't understand until you tried it (alot). Lets not forget about anodizing, sealing, engraving, decal, ect.. Possibly 6 - 10 adapters might put you in that range to afford one, but as a small business you constantly need to buy bits & turning tools, Taps, Dies, material, etc..

 

[Beat Takeshi]

Any places in NYC where I can get my Brevis collimated?

 

[Kholi]

I would like to see the low cost adaptor makers actually produce a "pro" model that has better build, adjustment and precision at cost that still makes it "low cost" relative to PS. Say 3-4 grand. At that price they could add much of the precision pros want but still at a price that doesn't have you weighing in on a RED.

Now that's what I'd like to see. Wonder how many people would actually fork over the three to four grand or so for the units though if they included everything you wanted from an adapter?

 

[Postmaster]

Hmm.... "Pro" Model huh?

I got my LEX today and it is build like a tank.
Pretty heavy. Since I have it snorkel up I openend up the bolts at the front cover and turned it 180 deg over so the thread for the support is on the downside.

No extra wishes regarding the housing.

Backfocus and related stuff:
For a pro model I would like to have 2 things:
I use different lenses on my Nikon mount. Nikon (of coursee) also several M42 Lenses and Pentasix Middle Format with adapters.
Of coure backfocus is way of with those.

If i would have something like the focus ring with marks/numbers that would move the GG back and forth to set for different lenses - that would be a "pro" thing"

Also the chance to move it up/down and side to side with screws. Maybe even twist it to compensate for lenses that are a tad off.

hmmm what else?

Changing the speed of the GG, changing different GGs with the flip of a switch like ND incamera Filters on pro cameras.

Build in remote FF... O.K. here it get´s over te top ;-)

Frank

Oh, I played with a PS last week. Ha! nowhere near the LEX.
I wonder why poeple still paying insane ammounts to PS?

 

[cardmaverick]

I'm not sure I would have added edge to edge softness to that list just yet.

I would totally agree with you on that!

Here's a question for the adapter makers out there...

When you are doing in house tests, do you monitor individual color channels? A lot of the softness you see in an adapter, or lens has to do with longitudinal chromatic aberration issues, in both the adapter AND host camera lens.

Have you ever thought about releasing custom achromats for various cameras? Every camera in the prosumer range has a zoom lens on it, but the big issue is the adapter design is forcing the host camera to use what is typically the WORST part of the lens in terms of longitudinal CA. Even when I stop my DVX100 Andromeda down to its optimal f/stop of 5.6, I still see softness issues, so I know its not just my camera lens.

Every host camera lens is different, so you can't really just have some generic achromat.

 

[Texanite]

Hey Wayne, I know you said the adjustable Nikon version has been shipping, but do you have an eta on the adjustable Canon FD mount? Think you'll have them before June or is that wishful thinking?

Thanks

Im not to sure about the Letus mount.

The SGpro's Nikon mount has a threaded ring. Sorry for the bad photo below, it was taken quickly with my digicam just to illustrate.

Loosening the 3 setscrews allows the back focus adjustment ring to be rotated. 1 full turn = 0.75mm of movement, so fine adjustment is easy.

 

[Dennis Wood]

Chris, that's an excellent point regarding colour channels. What I can tell you is that contrast characteristics have never been mentioned in any adapter review that I've ever seen. Our flip optics and flip achromat were modelled and tested specifically to achieve the maximum results physically possible in this regard. This is a large part of why our users report that the Brevis flip is sharper. It is pretty much impossible to do an achromat for every camera, and quite frankly, it's a waste of time. Focus plane curvature cannot be fixed with an achromat, although many believe this is true. In the case of the EX1, getting the camera into a lower zoom range gets the stock lens happier with close focus, but zoom in for a cine lens frame and the problem will bounce right back. We will never deal with problems like this because the overall optical performacne of the system would suffer too much. Cameras like the HVX200, XH-A1 and even the little HV20 work extraordinarily well with our flip system because they more or less do a good job at close focus accuracy across the image plane.

The backfocus system seen above is pretty much the Brevis micro-collimation system we've been shipping for the last year, but it works with all of our lens mounts, including the cine lenses.