Nikon 24mm calibration?

dlang

dlang

Well-known member
Hello...Ok looks like I'm gonna have to call on good ol' dvxuser one more time for yet another issue that's beyond me. I just bought a Nikon 24mm AIS (2.8) and according to the barrel markings I should be able to focus at a close distance of 1ft. for some reason though the minimal focus distance is 3 feet when testing this out. By the way I'm using the cinevate brevis non flip. When I mount my 50 and 85mm their markings are correct. I'm sure it has something to do with calibration but I need some further guidance. anyone want to chime in?
 
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Yes, the specs are a 1 foot minimum, when i had this problem it was because the adapter 's lens mount needed flanging, or it's back focus adjusted to phrase it differently. You are ideally supposed to back focus with the widest lens in the set and the others should fall in fine, but you may need to re-flange it for 24mm, mark the mount with some tape and try it , you can always go back that way!
Cheers
 
DEPTH OF PHIL said:
Yes, the specs are a 1 foot minimum, when i had this problem it was because the adapter 's lens mount needed flanging, or it's back focus adjusted to phrase it differently. You are ideally supposed to back focus with the widest lens in the set and the others should fall in fine, but you may need to re-flange it for 24mm, mark the mount with some tape and try it , you can always go back that way!
Cheers
Click to expand...


Ok, but here's the problem, the dust sheild blocks the lens mount from going far enough back to make that work? Also what is Flanging? Thanks so much for any further guidance
 
Oh . Flanging is a film term for adjusting the back focus. Dust shield, i'm not quite sure what you mean, on the Brevis/?

How do you back focus any lens? You have to be able to do this, also try moving it forward as well.
Does this dust shield come off, i'm sorry i can't picture the problem at hand, Can u Post a pict of the dust shield and the lens mount? Cheers
 
Well let me describe before I go takes pics. If you look down in the Brevis unit from the lens mount side (no lens mounted) then you will see a plastic shield that "seals" the unit so dust doesn't get on the GG. If you were to stick your finger in there (not recommended(: it would block your finger from going any further into the unit. I think that is called a dust shield?
 
...and this stops the mount from sliding backwards, can you back focus any lens with this dust shield?
The standard is flange or adjust back focus on the widest lens you will use. Did you email tech support at Brevis, Dennis is quite good about replying.
 
D, all REV2, MP.1 and MP.2 Brevis adapters have a micro-collimation ring (since borrowed by everyone else!) that should make getting correct collimation settings very easy to do. All of our lens mounts are designed relative to each other so generally once one is collimated, they all are. They are also designed for at least 1mm leeway in both directions so the shield should not be an issue. Now if this is an older unit, we do have the micro-collimation parts available in our catalog upgrades section as an update part too.

Cheers,
Dennis.
 
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