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Mounting filters with Nikon lenses

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#1 GeezerGazer

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Posted 06 October 2018 - 02:14 AM

Thanks to Eddgie, there are easy ways to mount 1.25" filters in Nikon to C-mount camera lens adapters.  But some filter cells are very thick (light path wise) and can cause vignetting.  So I decided to have a special, custom 12nm H-a filter made to fit perfectly into the bottom step inside a Nikon adapter.  But I've also figured out a way to get a normal 1.25" filter closer to the the C-mount so that it does not vignette, even with really thick filter cells.  

 

First, the custom filter method.  Last Monday, I ordered an Astronomik 12nm H-a filter from Germany.  I simply sent an email, had a response within an hour, paid $152 with PP and had a second response that it would take 2-3 days to make and 2-3 days to ship.  Well, that was Monday at noon Pacific time.  On Thursday, the filter arrived via FedEx delivery.  WOW!  That is excellent service!  I promptly blackened the edges and epoxied it to the bottom step inside my Nikon to C-mount adapter, which means there is no filter cell to obstruct the light path from the lens into the Mod 3C (see photos below).  The only problem with this method is that I need a different Nikon adapter for each filter that I use.  Necessity is the mother of invention....

 

So I worked out dimensions to fashion my own Nikon to C-mount adapter using "other" off-the-shelf parts... most of which I already had.  For this custom adapter method, I only purchased an Ebay $13 Nikon to M-42 (same as TT/T2 threads) adapter, screwed a 10mm extension tube onto the T2 threads of the adapter, screwed a 1.25" filter into a ScopeStuff filter capture ring and then screwed a ScopeStuff C2TT adapter over the filter capture ring.  This combination of parts is 2mm shorter than the official Nikon to C-mount adapter.  And, on the C-mount end, the filter is only 3mm deeper than my custom filter that is glued in (above).  With a light shining through this cobbled adapter containing a 640 IR filter with a thick filter cell, the filter is still close enough to the C-mount opening that the cell is not visible.  It provides the same clear light path that the custom filter provides.  

 

Pictures are worth 1,000 words so here are 6 to save time reading ...

 

Custom filter epoxied in bottom step inside Nikon to C-mount adapter

IMG_2698.jpg

 

C-mount end of adapter with filter inset 7mm from the end of the threads

IMG_2699.jpg

 

Adapter with filter connecting Nikon lens to Mod 3C (with an adapter I made to attach a short dovetail for mounting)

IMG_2700.jpg

 

With the adapter screwed into the Mod 3C, the lens can be changed in seconds

IMG_2701.jpg

 

The "official" Nikon to C-mount adapter is on the right in this image; the cobbled adapter using the Nikon to M42 adapter is on the left

IMG_2703.JPG

 



#2 GeezerGazer

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Posted 06 October 2018 - 02:28 AM

And here are the parts to make such an adapter, from L to R:  Ebay special, Nikon to M42 adapter, M42/10mm extension ring, ScopteStuff 1.25" filter capture ring (with filter screwed in), and a ScopeStuff C2TT (C-mount to M42 thread) adapter.

IMG_2705.jpg

 

This cobbled adapter is very secure and does not introduce flexure.  And, all of my lenses come to focus using it.  

IMG_2707.jpg

 

There's ALWAYS a way.  Next, I'll be working on adapting a 90 degree diagonal to my lenses to use them as spotting scopes.  There is this Kenko adapter https://www.adorama....nkls10nfab.html  which looks very tempting, but I've got most of the parts to try making it myself and I'll be able to change lenses! 

 

Clear Skies. 

 


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#3 DMala

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Posted 26 December 2018 - 06:34 PM

Hello all, I am posting here since the adapters/solutions discussed above may be relevant to my question.

 

I am trying to find a way to insert 1.25" filters in the sequence PVS-7/C-mount adapter/C to Pentax K adapter/Pentax K lenses.

 

Since the C to Pentax K adapter is inexpensive, maybe the simplest option is indeed to epoxy on the rear plate of the C to K adapter a ring with 1.25" filter threads, as suggested in many past discussions on this forum.

 

Question: should I go the cheaper way and find an old 1.25" filter to disassemble and use as source for the filter holding ring to be epoxied to the backplate of the C to K adapter, or should  I be concerned about vignetting and instead purchase from Scopestuff the $15.00 each - #TFA1 - 1.25" Filter Adapter for T-Thread Capture, which seems very flat ? 

 

 

So it would be this https://www.ebay.com...TMAAOSwRDpb7na7

 

Vs this  hthttps://www.ebay.com...UhIcl:rk:8:pf:0

 

Actually, I see now that the $$ difference is so small that unless I hear back that for some reason the ScopeStuff adapter will not work, I will go with that....



#4 GeezerGazer

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Posted 29 December 2018 - 01:34 PM

Having no experience with Pentax lenses, I'm not qualified to answer as to whether the assembly I composed for Nikon lenses will work for you.  But it should with the proper spacer; the 10mm TT extension might work but might not, depending on the focus point of the lens you select.  

 

If you need a short 1.25" filter ring to glue in to an adapter, PM me and I'll send you one I shortened but did not use.  It's free if you can use it.  


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#5 tmaestro

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Posted 02 January 2019 - 08:52 AM

Does Baader's UFC system have a solution?  Seems like there is a lot of adapter options, and the ability to swap filters without disassembling might have some appeal.

 

https://www.baader-p...r-changer).html



#6 SunBlack

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Posted 02 January 2019 - 06:12 PM

Ufc is intended for telescopes, not lenses


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