NikonGear'23

Gear Talk => Camera Talk => Topic started by: Frank Fremerey on June 15, 2016, 17:51:59

Title: FM-2n and Diopter correction
Post by: Frank Fremerey on June 15, 2016, 17:51:59
Aerobat's FM-2n I bought is still in the post but it already
got me thinking: How will I shoot it?

I bought some prepaid non reusable chemical sensors to do some
whacky experimental stuff with them. I also have some very decent
MF glass to draw light structures with photons. Plus a lot of not so decent...

Yet it just crossed my mind that my biological light sensors
are seriously challenged and the FM-2 might not have any means
to compensate for that but insanely expensive screw in lenses.

Help! Please...
Title: Re: FM-2n and Diopter correction
Post by: Bjørn Rørslett on June 15, 2016, 17:59:54
You might need diopter lenses for the ocular, Frank. If I recall correctly, the finder is set for -1 dioptri which is the Japanese norm. It has no further means of direct adjustment.

I just checked with a pristine FM2 sitting in my cupboard and I definitively need my reading glasses to see anything in the otherwise nice, bright finder. Do put an eyecup on the ocular to save your spectacles from being scratched.
Title: Re: FM-2n and Diopter correction
Post by: charlie on June 15, 2016, 20:00:06
Provia 400, so sad to see that one go.
Title: Re: FM-2n and Diopter correction
Post by: Frank Fremerey on June 15, 2016, 20:00:30
I am +2.5 so do I need a +3.5 correction lens then? Or do I need a screw in rubber plus reading glasses?

screwin'rubber ..... hahahaha
Title: Re: FM-2n and Diopter correction
Post by: Bjørn Rørslett on June 15, 2016, 20:07:38
Try without glasses first.

The reason they put in -1 as a standard is the need for seeing both finder information, and ground-glass image, reasonably sharp at the same time. Thus the inherent focus of the system is at 1 m, explaining the -1 dioptre setting. People have different ability to accommodate their eye sight thus a practice test is recommended before you commence the screwing-in of any attachment lens(es).
Title: Re: FM-2n and Diopter correction
Post by: Frank Fremerey on June 15, 2016, 21:00:59
And where do I get the rubber and the correctional glass elements ... just in case ...
Title: Re: FM-2n and Diopter correction
Post by: Bjørn Rørslett on June 15, 2016, 22:07:01
Rubber eye cup is standard Nikon accessory - ask your dealer. They should also be able to supply the dioptre attachments for the ocular.
Title: Re: FM-2n and Diopter correction
Post by: pluton on June 16, 2016, 06:16:10
Bjørn's advice to try in person is highly advised, because Nikon has a peculiar naming convention for their eyepiece diopters.  The diopters are named for the net camera finder  +  diopter value, not for the diopter value of the lens by itself.  If you want to shoot using your spectacles, by all means test while wearing them.
Title: Re: FM-2n and Diopter correction
Post by: Matthew Currie on June 16, 2016, 07:08:23
I'd definitely try it out first.  I am comfortable reading at 2.5 to 3.5,  but find a +1 diopter about right on a Nikon viewfinder.  Stacking two +1's on top of each other is too much.  At one point I ordered a +1 for my F3HP, and KEH accidentally included a +3 along with it, and it's totally unusable.

Figure what diopter you'd need to see a computer screen from a meter away, and that's pretty close to what you need in a correction lens.

I've gotten a couple of these things used from KEH.com.  Some of the newer diopter rings have a rubber rim that's a bit heavier than it used to be.  Nikon's own chart is confusing.  There are actually only two thread sizes made - one for the earlier Nikon Photomics and Nikkormats, through the non-HP F3, and one for the HP F3 and subsequent models with threaded eyepieces.  Any other differences are in ring design, not threads.
Title: Re: FM-2n and Diopter correction
Post by: Frank Fremerey on June 16, 2016, 10:29:50
Confusing. I prefer NOT to wear glasses because I cannot see anything with them except in the very near field

Computer Screen 1 Meter is roughly +1.5 to +2.0
Title: Re: FM-2n and Diopter correction
Post by: pluton on June 16, 2016, 16:31:39
Confusing. I prefer NOT to wear glasses because I cannot see anything with them except in the very near field

Computer Screen 1 Meter is roughly +1.5 to +2.0

In theory, the Nikon "0" diopter or the Nikon "1" diopter should accommodate your vision.
Title: Re: FM-2n and Diopter correction
Post by: Eddie Draaisma on June 16, 2016, 16:57:13
My eyesight is still good at large distances, but not at the 1m virtual finder distance (-1 diopter) anymore. For the old Nikons without built-in diopter adjustment (including a FM-2n) I bought +1 diopter screw-in eyepieces from EBay. Problem solved. Note that the diopters for the Fujifilm X-Pro1 (still available as new) will fit the FM-2n.
Title: Re: FM-2n and Diopter correction
Post by: abergon on June 16, 2016, 19:29:30
There is also the nuclear option: laser eye surgery. I am writing from personal experience.
Title: Re: FM-2n and Diopter correction
Post by: Frank Fremerey on June 16, 2016, 19:42:04
Nono. It is reading glasses. And it is a non laserable aneurism. Laser simply is no solution in my case.

But. I ordered a +1 Nikon Diopter brand new from Japan at 20 Euros incl. Shipping.

I studied the Nikon documentation on that topic on service nikoneurope eu

hope all will be worth the effort in the end.
Title: Re: FM-2n and Diopter correction
Post by: Eddie Draaisma on June 16, 2016, 23:52:18
Nono. It is reading glasses. And it is a non laserable aneurism. Laser simply is no solution in my case.

But. I ordered a +1 Nikon Diopter brand new from Japan at 20 Euros incl. Shipping.

I studied the Nikon documentation on that topic on service nikoneurope eu

hope all will be worth the effort in the end.

The +1 should work for you if your eyesight is (still) good at infinity.

You will find out that on the FM2 the 35/1.4Ais gives the impression of a much bigger lens. No (MD11/MD12) motordrive??
Title: Re: FM-2n and Diopter correction
Post by: David H. Hartman on June 17, 2016, 03:25:13
I am +2.5 so do I need a +3.5 correction lens then? Or do I need a screw in rubber plus reading glasses?

screwin'rubber ..... hahahaha

Check this out! The diopter marked on the accessory eyepiece may be the combined diopter. As I recall there is a zero diopter eyepiece which is probably a +1 as -1 +1 = 0. Photography in Malaysia would be a good place to check.

Best,

Dave

---

You might download a Nikon FM3a manual from Nikon as the FM3a uses the same eyepieces.
Title: Re: FM-2n and Diopter correction
Post by: Frank Fremerey on June 17, 2016, 09:34:12
Thank you all. I wait for the packages from Suisse and Japan to arrive. So much other work to do.
Title: Re: FM-2n and Diopter correction
Post by: Frank Fremerey on June 17, 2016, 10:10:10
https://nikoneurope-en.custhelp.com/app/answers/detail/a_id/953/~/slr-viewfinder-diopter-adjustment

question remaining: which rubber eye piece will work in conjuction with
the correctional facility ;-)
Title: Re: FM-2n and Diopter correction
Post by: Matthew Currie on June 17, 2016, 19:29:53
If  I read the charts right, the FM2 takes the 19 mm. thread, common to the F and F2, etc.  If the lenses are the same as the old F ones, they are all metal, and the original F rubber eye cup fits over them.  That is, as far as I know, the standard rubber eye cup both for the Photomic F and for the DG-2 magnifier, etc. I have an eye cup on one of my F's., but the others are bare.  Glasses scratching is not an issue, because the eye point is not high enough for glasses anyway.

If the newer version has a rubber ring, you will probably have to remove that to put on an eye cup, but you also may not need the eye cup.

The accompanying picture shows an F diopter with an eye cup on it, and the same type F diopter with no eye cup.  The eye cup just stretches over the flange, and is held tight when it's screwed in.

In front of these are a pair of HP diopters.  The left hand one has a small rubber ring glued to it.  The right hand one has a wider metal flange, and the rubber ring (behind it) stretches over it.  I do not know which versions are meant for which cameras or which one of the two version is newer. 
Title: Re: FM-2n and Diopter correction
Post by: the solitaire on June 17, 2016, 20:34:56
The Nikon F3 DE-2 finder also uses 19mm thread. With the DE-3 finder Nikon introduced a 22mm thread for correction eyepieces
Title: Re: FM-2n and Diopter correction
Post by: Frank Fremerey on June 23, 2016, 10:33:56
Post from Japan arrived!

A registered delivery from Japan including diopter is cheaper than the unregistered postage costs from Suisse alone.

Pity: The best way to focus the FM-2 for me is if I screw out both pieces of glass. The Diopter does not help.
Title: Re: FM-2n and Diopter correction
Post by: David H. Hartman on June 23, 2016, 20:13:47
With the standard eye piece off you'll still be at -1 diopter as with it on. I'm not making sense of taking it off.

Dave
Title: Re: FM-2n and Diopter correction
Post by: pluton on June 24, 2016, 00:40:00
Unless Frank's FM2 came with a "0" diopter already in place?  It's pretty easy to tell by looking through the diopter held out at half arm's length.
Title: Re: FM-2n and Diopter correction
Post by: Frank Fremerey on June 24, 2016, 08:18:53
With the installed original glass the VF looks more blurry than without. With the +1 it looks even more blurry

Best VF for manual focus is the D500 and the D600 follows close behind.