VIDOM help wanted - apply within.

[bill]

So.

My VIDOM arrived today.

Some questions to those with more experience.

1. There's a small lump of cack inside. Is it easy to take it apart and clean it out?
1a.If so, where do I start?

2. I understand how the parallax correction works, but why is there a leetle line on the focal length selector beside the main line? When should I use that?

3. I know the image is inverted, and that's not a problem, but why can I turn it upside down - what advantage does that give me?

Thanks chaps!

Regards,

Bill

[stumac]

Bill, I have also aquired a VIDOM recently, mine also has dirt inside, the image is not inverted but reversed laterally. there were several versions of this finder, mine has a removable collar on the nose with two holes for a pin spanner which I will make in the next few weeks.
I havent tried to dismantle it yet but I will. Keep in touch, I will let you know of progress.

Regards, Stuart

[bill]

Hi Stuart,

I've been busy since my first post...

First of all, I tried from the back. I undid the tiny grub-screw on the milled bit. That milled bit then unscrews. Under it are three more screws, one grub and two slightly larger. I undid them all, but couldn't get any further. I reassembled that bit, and turned my attention to the front. Although I don't have circlip pliers, I was able to shift the front collar using two jeweller's screwdrivers in tandem. Underneath are three more grubscrews set equidistant around the nose. If you uncrew these, the whole nose drops out easily into your hand.

I carefully cleaned the glass at the back of the nose with a microfibre cloth, then used a can of compressed air to give the rest of the assembly a good blasting. While there, admire the quality of the internal construction; you can see that the different focal length views are achieved by two L-shaped pieces of metal that move in unison when you rotate the selector ring.

I put it all back together, and voila! The original bit of cack has gone...

...to be replaced by a tiny shred of fluff...

C'est la vie. When I have time I'll "field strip" the bugger again and get that out too! At least now I know how.

Regards,

Bill

[doubice]

Originally Posted by bill

So.

My VIDOM arrived today.

Some questions to those with more experience.

1. I understand how the parallax correction works, but why is there a leetle line on the focal length selector beside the main line? When should I use that?

2. I know the image is inverted, and that's not a problem, but why can I turn it upside down - what advantage does that give me?


Bill

Bill,

Sorry - I was off line and could not help with the disassembly instructions. I see however, that you did quite well. Fluff sounds better than cack......

1) The short line on the focal length selector allows for the lens' narrower field of view at short distances: the two L-shaped plates will show less when the dial is set to the short line.

2) Due to the optical design of the VIDOM, not only is the image lateraly reversed, but it will also turn upside down when viewing vertically. That is when you will turn the milled ring at the ocular...... est voilà - the image is right side up again.

All the best,

Jan

[stumac]

Thanks for the info Bill, I wont have to tread so carefully when I start.

Regards, Stuart.

[flatfour]

Jan - I always understood that the little short line was the infra red setting for any distance.

[doubice]

Originally Posted by flatfour

Jan - I always understood that the little short line was the infra red setting for any distance.

Anthony,

Only lenses have a separate IR focusing index, as it is needed for correctly focusing IR films. Viewfinders do not need this - all you are doing is sighting through them.

Cheers,

Jan

[bill]

Thanks Jan, much appreciated. Thought it might be something like that.

Roll on the weekend when I can try this baby out...

Regards,

Bill

[jc_braconi]

Parallaxe setting is on the foot and in the viewfinder too.
you have a long index and a short one : easy to understand the frame is different at short instead at long distance.
you can see this on fixed focal outside viewfinders with the interupted line in the brilliant frame for short distances.
cheers
jc