using nikon lens without iris ring.. a way to lock iris?

[Joe Kocsis]

I have a couple Nikon lenses that I want to use on my Brevis setup that dont have iris rings.. a 70-200VR f2.8 zoom for example..

The issue with the non iris ring lenses is that the iris snaps shut..

I know I can tape the iris wide open, but I was wondering if there is was a clip or something available that will lock the iris open, or even allow me to set it?

 

[Huy Vu]

You need a Nikon DSLR body. Put the lens on the camera, set the aperture you want, then press and hold the DOF Preview button while taking the lens off. It will stay at that aperture and then you can mount on to the adapter.

 

[PhantomVideo]

Correct me if im wrong but, I'm fairly sure G series lenses don't work that way, thats an EOS mount method an't it?,

This is how i open my DX/G lens
http://www.dvxuser.com/V6/showthread.php?t=166981&highlight=16mm+F2.8

 

[Efexone]

yea, G lenses use spring loaded apertures. it wont stay in place like that. it will always stop down.

 

[Joe Kocsis]

yes it's a G lens.. and it is spring loaded, and that does not work.. The piece of foam is an interesting idea...

 

[PhantomVideo]

Thats why im suprised why only the adaptormax and red mount have a g lens screw, i think I'll make my own man i wish my Cinevate Nikon mount was better lenses are always loose in it

 

[Joe Kocsis]

My Brevis lens mount is very tight.. Maybe you should have them replace yours? What's adaptormax?

 

[PhantomVideo]

The Red On GDX mount
http://www.youtube.com/watch?v=q4Y9uufZB7Y

For Sony EX3 allows the mounting of nikon and nikon G lenses for Tele and Macro work, but the lens mount should be easy to replicate
http://www.cameraadaptors.com/

Wow yeah this mount has been loose since day dot im puting a clip in the mount lock to stop lenses unmounting themselfs

 

[bmw1602]

I use a small coffee type straw that I cut to length. I can actually slide it back and forth and stop down a bit.... I'll post a pic later...

I use this on my 70-200mm f2.8 VR and a 17-55 f2.8 DX lens... on my redrock M2e

Here is the 70-200 when I was shooting some racing stuff.....

 

[Joe Kocsis]

Pretty sick... I'm looking forward to trying my 70-200 out next week potentially on some moto racing stuff.

 

[PhantomVideo]

how much of your red rock does your 17-55 cover?

 

[bmw1602]

how much of your red rock does your 17-55 cover?

check out my post........doing some more tests today.....

http://www.dvxuser.com/V6/showthread.php?t=175004

 

[bmw1602]

Here's what I do,

grab a coffee mixer/straw, slide it in until it stops and cut it to length. This way it's too long to become unretrivable. See if you cut it short it might slide into the slot and you may not be able to take it out....

then cut it to length.........you can even slide it back and forth a bit to adjust f stop.

It goes on my redrock like this no problem.......just don't forget it there and mount it back on your nikon....

voila!


if anyone has a better method.....I'm all ears.....

 

[DeGrey]

I little wad of paper works too. Basically anything to hold the arm open that won't fall out. I took an AF lens with me for a shoot and forgot to lock the arm open. I just grabbed a scrap of paper, rolled up the corner of it, and jammed the arm open. The next day I bought a Zeiss ZF mount with manual aperture control