vivitar 120-600 with viv x4 help

h00py · Joined: 17 Jul 2014 Posts: 16

wonder if anybody has ever disassembled the vivitar x4 teleconvertor could help?
i picked one up and had fungus in it,so not being the brightest Sad

i tried to clean it,trouble is when i unscrewed the lens barrel and unscrewed the end cap
the glass elements weren't for moving,so stupidly i gave it a tap, and it gave me a flood of lenses along with metal bands,so bang goes the order they were in Sad

anyways after a few attempts of rebuilding/disassembly i think i might have it though unsure
the 120-600 lens had fungus also Sad

i know lucky me,anyways removed it from front but cannot and do not want to disassemble rear element,i will put up with knowing it's
there

so question is does anyone have a diagram on how teleconvertor elements should be placed?

i have a 500d with an fd adapter (i removed the infinity glass as it was causing bright circle centre of images)

the pictures are as it is now..are these acceptable as they are or do i need to rebuild?...images are 50% of original and no processing
thanx for any reply
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marcusBMG · Joined: 07 Dec 2012 Posts: 1304 Location: Conwy N Wales

Hi h00py, thanks for posting abut the interesting old viv 120-600mm. Some of those pics are showing some decent detail.

My experience with old tc's is pretty much all bad. I use more recent 1.4x tc's, and occasionally my best 2x tc's (original adaptall 01F, vivitar macro MC7) with my 300mm f2.8. I doubt that the 120-600mm will do well with any tc's, it's already at f8, add a tc and you're at f11, f16, diffraction will be kicking in, I doubt that the images will show better than cropped or resized images.
Is the tc you're trying to reassemble really 4x? Sounds unusable to me, 4 stops of light loss...

h00py · Joined: 17 Jul 2014 Posts: 16

my mistake not x4 Laugh 1

need better glasses i think lmao
its a vivitar mc 3x-4 fl-fd
the f stop doesn't register on camera ? it just shows f00 i have to use the stop down on lens if that makes sense,i'm still a noob as far as settings and stuff
all shots above were shot pretty slow at 1/80 to 1/100 using a tripod,i'm hoping on a break in weather to try again with better light
i just wasn't sure if i had any elements in back to front or not
thanks for reply

marcusBMG · Joined: 07 Dec 2012 Posts: 1304 Location: Conwy N Wales

Well I would regard a 3x tc as pretty unusable too, I did try one once (and then cannibalised it to make a digiscoping adapter) but as a rule of thumb what you gain in magnifiacation you lose in magnified aberrations, new aberrations, magnified camera shake and vibration from inevitably slow shutter speeds, focus errors from the wafer thin depth of field and because it gets difficult to see the exact plane of critical focus due to the lack of light (3 stops lost)getting into your VF. When I've done experiments with eg tc's and ultra telephoto focal lengths (equivalent focal lengths allowing for sensor size) of 600mm and up I have tended to resort to my mirrorless cameras because the EVF's on those auto compensate for the dim light. And the set up is a heavy tripod, weighted with eg a sandbag ideally, lens with a long plate adapter to balance it, mirror lock up, 2 secs timer, remote cable release. And a small sandbag or two on the lens/camera to dampen vibration doesn't go amiss. you get the idea.... it's difficult to achieve what might be the best iq from ultra tp set ups like this.
And in anything other than best light, just don't bother, you're wasting your time.
But have fun.

h00py · Joined: 17 Jul 2014 Posts: 16

think i will leave it off then,thanks for reply anyway