Nikon 16mm, Magic filter & close focus -

Today I have recieve Peter Rowlands +1 diopter that can be fitted to the back of my 16mm.

I am hopping with this diopter i can fix my AF focus problem that i have with my small dome.

The problem may be that the virtual image is very close and so the 16mm lens can't focus on it anymore.

Now, if you read the 16mm manual you must use the 16mm with the the transparent filter (L37c) that came with the lens.

If you remove the filter you can have a better close focus but you can't focus to infinity. The same for the +1 diopter.

But this is topside. I must test it underwater to...

I have make a topside test to see how close I can focus to the subject .

Th close focus resultat was

With +1 diopter ca 15,5 mm to 30.5

without diopter and magic filter ca 19,5 to 120

with nikon original diopter 23,5 mm to infinity

then one more with +0,5 diopter. from ca 19,5mm - 94mm

Lambis

btw if i use the diopter how can I atach the magic filter? on the back of the diopter?

That’s interesting. I am not familiar with Nikon gear. But this means the 16mm Nikkor fisheye is actually designed for underwater usage behind a dome and the little included rear side “filter†transforms it into a topside lens, hehe

Honestly, from the results I understand removing the included rear side “filter†has the same effect as mounting dioptres on lenses for underwater. I would start to find out how the lens focuses without the included “filter†topside (from x cm to y m). But there are several Nikon 16mm shooters around here, maybe someone knows how strong the little “filter†(actually this should be better called a negative dioptre?) is? Does the lens manual say something about it?

Julian

Hi Lambis,

Sorry to hear about all your troubles with the 16mm

anyway just to boost your confidence a little, I'll tell you that

I use Sea & Sea , I only own a COMPACT dome port, Roughly same size as the Ikelite units and Subal smaller domes.

I've never had an issue with either 15mm FE or my old 16mm Nikkor working behind it whatsoever.

i always thought that if the lens was capable of focusing closer than 12" then it would not require any additional closeup filters. This has held quite true for me.

I can use my 18-70 AF-S behind the compact dome and an extension ring and it will work just fine.

I hope you manage to sort out this issue, Best of luck.

Regards and all the best for 2006

craig

p.s Julian if your reading this, can you tell me what 105 focus ring you used to work with your 10-20mm ... Nikon 105 or sigma 105 ?.. with the dremel of course.

Hi Craig,

How close the lens has to focus depends on the dome size. I think Lambis’ dome has a very small curvature and the Nikon 16mm doesn’t focus very close with this “mysterious†little filter on the rear installed. But I don't know and Lambis will tell us

I don’t have Sigma 50mm / 105mm focus gears. Sealux machined a zoom gear for the 10-20mm. Sorry for my lack of English language skills, what does “dremel†mean?

Julian

Julian.

Happy New Year to you !

A "Dremel" is a a compact hi-speed multi purpose grinding tool !

http://www.dremel.com/ Very handy for adjusting focus / zoom gears etc. No workshop should be without one.

Regarding the focus issues with the 16mm.

A small story is neccessary

On a extended field trip I flooded my surviving D2X ( I had already killed a couple ), field repairs got it functioning with the exception of auto focus.

This caused me to go back to basics, and manually focus the lens ,No real problem just something I hadn't done for a long time. The results were sufficient that I now often ( always ) shoot this lens as a manual device.

Perhaps Lambis should try shooting the lens as a manual lens and see if the issues go away. : B)

Peter

Peter :

Peter, happy new year to you too

OK, it's a brand, that's why I didn't find it in the dictionary

Julian

Sorry for the confusion Julian.

I thought i saw a posting from you a while ago, saying that you Dremelled a 105 ring to use with your 10-20mm... My Mistake.

regards

craig

Does anyone know if this port is actually designed to work with the 16mm?

I saw the port a couple of months ago at Sea Optics, who, if memory serves, said it was for the 10.5mm. My impression was that if something as cute and compact as this actually worked someone would have made one in the past, I would have bought it and saved myself the trouble of lugging huge fisheye ports around the world.

I can't actually find the port on either the Nexus or SeaOptics site.

Edit:

I FINALLY found this on the port page for the N90 (seems an odd place to list the 10.5 port but anyway...)

( Here)

FP-120-7 Fisheye Port 120 for 10.5 Fisheye lens $955.00

I'd assume from that that the port is for the 10.5 lens only. I very much doubt that adding any sort of extension ring will 8improve things; it will most likely make things worse..

If you really want to use the 16mm get yourself one of the FP 230-3 ports. Personally I'd just get rid of the 16mm fisheye .

Andrew

Nexus usa usanexus

say its work with both lenses.

That was the reason that i have buy the 16mm.

maybe is time that Woody from Nexus USA can answer this question

All what i have hear was that the FP 230-3 port is better.

I know that the FP 230-3 is working with both lenses.

What Nexus must do is to asnwer finally if the FP120-7 is working with both lenses.

If not , why they put it on there webpage?

Anyway.. i will sonn make a final test on a pool. I think that i can fix it.

I think the problem is that the 16mm cant focus close enough and becauce my small dome (That i love btw...) create a virtual image that is very close to my 16mm lens the lens can,t focus. With +1 diopter i can move the close focus ca 8 cm and may this will help.. If not i will sell my nikon 16mm

Sometimes compamies and resealers just put infos on the web without to actually have test if it is working or not... Very bad fot the customers but ever for the reseallers...

lambis

Sorry for the confusion Julian.

 

I thought i saw a posting from you a while ago, saying that you Dremelled a 105 ring to use with your 10-20mm... My Mistake.

<{POST_SNAPBACK}>

I saw Dremel has also a German site, not your mistake, it's just called "Multifunktionswerkzeug" :-)

Can't find the topic, but I remember there was someone with some macro focus gear adapted for the 10-20 ... .

Lambis,

let us know what your test will show with different combinations.

Julian

Julian,

I am the dremelling offender.

Craig for you info re the zoom ring modification.

http://wetpixel.com/forums/index.php?showtopic=9700

Hi Lambis,

The FP120 has a really poor reputation in Japan for distortion...

The FP170 acrylic dome and new FP160 optical glass dome both work well with the 10.5 & 16, and are tolerable w/ the 12-24, and are what I suggest to my customers. We also have Athena's Fisheye Dome Ports, which are now discontinued, but have an excellent reputation.

Craig, a 17-35 Zoom gear has the right ID and fits nicely on zoom ring of the Sigma 10-20mm lens. I haven't tried Sea & Sea's to see if it works, but I have tried an Athena for Sea & Sea gear, and it works very well.