Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Doubts on swapping mounts... [related to Birger's mount]

I'm not worried about anything. Fear is of the Enemy!

I'm not grinding or shimming anything.

I can walk into a lens store, buy a Canon lens, put it on my 12MP Camera and take beautiful pictures without grinding or collimating anything.

I will concern myself with telling a good story instead of worrying about grinding and collimating.

Birger Engineering has been recognized by NASA for their work and for Over two years been developing smart controllers which allows the full control of Canon EF-mount lenses without requiring the use of a Canon EOS camera body. I will trust him.

After-all, the story even told with a DV camera will sell.
 
Evin Grant said:
What about when you switch them, how are YOU going to get them accurate?
Click to expand...

I don't know Evin, this thread and the collimation one concerns me, it really does. How should I get them accurate without instantly having years of AC experience and a $3500 collimator?
 
Evin Grant said:
What about when you switch them, how are YOU going to get them accurate?
Click to expand...

Hi Evin,

That has always been my point, depending where the shims are placed, if everything is clean you might get lucky. Avoid switching mounts would be my advice.

Hi Shawn,

How would you know if they were out by 5 microns? I think you underestimate how difficult working to those tolerances is, if every piece had to be interchangeable then everything would have to be made to +/- 2.5 microns.

Stephen

EDIT The PL fitted mount should be correctly set at the factory. Mounts are usually made short, it's far easier to shim than grind. Still camera lenses often need grinding..
 
And if you think changing mounts is going to be fun wait until you see "Red Rack over" this interesting technique duplicates the classic Mitchell camera usage. Where it will be necessary to move the body out of alignment with the lens in order to aim it by looking directly through the lens with a special eyepiece which is pressed against the back of the lens. Remember the Kinetta was going to offer a hand crank mode. How retro we gotta be so this is a problem????

Several things RED might actually do:
1. duplicate the interchangeable lens systm on the Eclair cameras which requires no shimming
2. machine the mounts and bodies so accurately there is no shimming needed
3 build shims so that once a mount was shimmed for a particular body it would always be correctly adjusted for that body.

Folks it's a new century lets not judge this based on putting a PL mount on a 2C for gawhsdd sakeeee...
 
Shawn Nelson said:
I don't know Evin, this thread and the collimation one concerns me, it really does. How should I get them accurate without instantly having years of AC experience and a $3500 collimator?
Click to expand...
It does seem I have launched worries over you... :) But believe me you're not the only one here. The most part of the future RED users are fairly concerned even if silent sometimes. My PM box can testify it!
 
Shawn Nelson said:
I don't know Evin, this thread and the collimation one concerns me, it really does. How should I get them accurate without instantly having years of AC experience and a $3500 collimator?
Click to expand...

The good news is that you can check immediately if your mount is good by shooting a second of footage at a few marked and taped distances (Focus chart preferably) as well as a shot as close to infinity as you can find, and then open them in Red cine off a CF card and look at the 4K still. It's not a perfect solution but it should tell you if your really out.
 
Hi Guys, Flange focal distance is fun to talk about and all but this is getting a little overblown.

1. It's likely that the mount will stay accurate. Precision ground Metal to Metal held by 6 or 8 screws.

2. It's easy to check if it's OK with simple techniques, assuming that you have at least one lens that you trust.

3. Focus problems are 99% more likely to come from simple mis focusing than from mount alignment problems.

4. There is much more slop inside most lenses and at the mount itself than in the mount / body junction. Stress about these factors first.

5. When you get a new mount you'll have to test it and set it up, but once this is done careful switching will not be a big deal.

6. It's not like on a film camera where things could look in focus in the finder and be N/G on the film.

Matt Uhry
www.mattuhry.com
 
3 build shims so that once a mount was shimmed for a particular body it would always be correctly adjusted for that body. [/QUOTE said:
Thats the theory.

Stephen
Click to expand...
 
Matt Uhry said:
Hi Guys, Flange focal distance is fun to talk about and all but this is getting a little overblown.

1. It's likely that the mount will stay accurate. Precision ground Metal to Metal held by 6 or 8 screws.

2. It's easy to check if it's OK with simple techniques, assuming that you have at least one lens that you trust.

3. Focus problems are 99% more likely to come from simple mis focusing than from mount alignment problems.

4. There is much more slop inside most lenses and at the mount itself than in the mount / body junction. Stress about these factors first.

5. When you get a new mount you'll have to test it and set it up, but once this is done careful switching will not be a big deal.

6. It's not like on a film camera where things could look in focus in the finder and be N/G on the film.

Matt Uhry
www.mattuhry.com
Click to expand...


here is a post from someone that i'm used to read and appreciate.. it's a shame it may seem to me he forgot sometimes he is a free spirit.. one of us.. and to be DoP is just an add value.. i'd like to read you here more than often, matt..

________________


stephen is another heavy weight posters.. most of you think i do no like him.. who thinks such silly untruth could not be more WRONG..

stephen is one of the most knowledge people posting among us.. i hope david mullen may forgive me but though his posts are often accurate.. they're always very distant.. far away from us.. the people.. but that's the way like he likes to be.. to be among us perhaps.. i cannot judge, sure.. i do not know him unless through his posts.. i prefer the most democratic stephen or matt.

well, using this word related to stephen.. democratic.. seems to me a heresy.. but not now.. since we are in honey moon.. :) he stopped with the FUD and with the DoP talk.. at least, during these vacations.. :matrix:

stephen is also one of the most cool guys at ###.com forums.. specially here.. even if sometimes it may seem to me he forgot how much democratic he is.. democratic is the word and my own belief.. :detective2: and he had followed other ones there.. spreading FUD can be his way of being.. a matter of personality, perhaps.. i already posted this thought before but seems to me there was who thought i was to be simply ironic..

here he's safe.. we are safe.. because this is a place for free people.. like matt.. maybe that's why we both love the russian glass.. :watsup:

________________


and sure, we need to be sure there won't be bugs with the changing mounts.. and stephen and matt are here to help us to get the job.. i hope, we all hope.

________________


edit
like ortega gasset said.. a man is himself (or herself) and his (or her) own circumstances.. reduser is the face of jarred.. like the ###.com forums or this or that post is the face of their own..
 
birgerEngineer said:
TJ understands. :innocent:
Click to expand...

Okay cool, that sounds good.

I do think there's a chance that Red and Birger completely solve the entire problem and we wouldn't even need to mention the words "collimator" or "flange distance" unless we dropped a lens or camera and were trying to get things back in whack. At which point I'd gladly go hunt down a tech.
 
With all this talk about collimating a lens, has anyone thought about the sensor? What if the sensor itself is 5 microns off in one direction? I would think this would be a problem that adjusting a lens couldn't even begin to fix.
 
You must log in or register to reply here.
Back
Top