11 replies to this topic

[nfoto]

Here, we will post a random series of hopefully useful insider's tips. The UV world of photography always has given the photographer practical challenges and hurdles to overcome. Perhaps reading through this thread can help answer questions you didn't even realise existed?

Any member of the UV site is welcome to add their own tips of course. Insights are to be shared.

I'll start by some tips on using filters.

The work-horse filter for many of us is the Baader U (Venus) filter, preferably Generation 2 or later. Any of these in 2" (48 mm thread) already is at least Generation 2.

Being designed for astrophotography, the Baader has the (to photographers at least) unusual 48 mm thread. It is also mounted in a rather fragile cell where it should be free to rattle around a bit thus avoiding any surface tension. The filter itself is very delicate and easily breaks if you drop it. All of this are bad news for a photographer doing field work because Murphy's Law ensures something will go wrong and dropping filters is one of those things. This is not theory as I have witnessed Andrea do this in the field and results were not good as far as having an unbroken filter is concerned. The Baader really shatters into a myriad of sharp shards when it breaks. Getting one of those shards inserted in your hand is painful (personal experience).

So, first of all, add a 48 mm step ring to the front of the Baader cell. That will give additional strength and make the filter tolerate more in the field. You can use either a 48-46 step-down or a 48-49 or 48-52 step-up ring for the front. All of these are cheap and easily found on eBay or similar. To the rear of the filter cell, add a suitable step ring so you can mount the entire component into a K2 ring (52 mm female threads). This adds even more protection. Add a K3 ring (female bayonet mount with 52 mm male threads) to have a nice quick-locking filter for your UV lens.



Shown above are all the required pieces for the filter kit: A Baader U 2" in its thin, flimsy filter cell, two step rings for front and rear of the filter cell, respectively, a K2 and a K3 ring to complete the mounting procedure.



The filter cell has been reinforced by adding step rings to either side of it.



The completed quick-release Baader U2 unit attached to one of my UV-Nikkors. Ready to take on the hardship of the big outdoors.

NB: I used a 48-46 mm step ring here because rummaging for the better size 52-48 did not net me anything. I do know I have this step ring somewhere so maybe I'll upgrade later.

[Andrea B.]

Here's what a shattered Baader U looks like in case anyone was wondering.

[Akira]

Andrea, that is one of the painful images I wouldn't want to see...

Anyway, to put the topic a little further, I found an M42 lens to Nikon F camera adapter made by Kindai International accepts the 1.25" Baader. It originally has a concave optical element that works as teleconverter and allow the M42 lens to focus at infinity with sacrificing the image quality of the attached lens as well as the meaning of using that lens probably.

With the optical element replaced with the 1.25" Baader U, it is easy to attach the filter onto the EL Nikkors 80/5.6 and 105/5.6 via some BORG adapter rings. The filter is small but doesn't cause any vignetting when attached to these enlarger lenses.

Edited by Akira, 07 June 2013 - 02:35.

[nfoto]

Our minds think alike, Akira. I have the equivalent for my 1.25" Baader-U. The M42->F is made by Bower (or so the stamped-on text says) but probably just another OEM product. By removing the infinity-correction glass inside, the Baader cell fits precisely into the opening. No light leaks at all. Add the K3 to the lens and you again are in business.

[nfoto]

Another tip for people tired of tracking down an elusive BR-15 adapter or not willing to pay the exorbitant price if you are lucky enough to find one:

BR-15 makes it possible to mount 39 mm Leica thread lenses to an "F" mount. You often need this for attaching enlarger lenses to Nikon-mount based devices such as a bellows or extension tube. The 65 mm f/4.5 and 120 mm f/6.3 Macro-Nikkors also use this fitting.

The easiest make-your own BR15 uses the following parts: "F"-mount by a BR2/2A ring (has 52 mm male threads), a step-down ring 52 mm -> M42, and the thin step-up 39 mm - M42 to complete the "BR15" look-alike. About 55$ total price off eBay unless you have some of the components already. The solution has the added advantage it'll work with M42 lenses as well so is more versatile than the original.

The real lesson is that you need to pick up some K-ring sets before they get too pricey on eBay. The K1 is excellent for moving in closer with wide-angle lenses such as the 20 mm f/3.5 Nikkor; the K2 sees a lot of use for mounting filters etc.; K3 is used for making quick-release filter kits; and K4 and K5 can be combined to make improvised sun shades, long extension tubes, or whatever your imagination can conjure up. I think I must have purchased at least 20 such K-ring sets over the years and could do with more. Add a few BR2/"As and some BR3s and you are ready to take on almost anything the UV world requires of you.

[Akira]

Another way to attach a 39mm LTM lens to NIkon F mount camera is to modify K2 ring. I used a BORG M42 to LTM adapter ring with its flange trimmed. The diameter of the inner opening of K2 ring is slightly smaller than M42 thread, so I can screw the M42 thread into the opening, just like a self-tapping screw.

I made the adpter in order to attach U-360/BG40 filter pack onto JML 50/3.5 enlarger lens. You can mount the JML and then attach K5 ring around JML which accepts the filter pack.

Also, you can attach BR-2A onto K5 and reverse-mount the JML. That's how I shot the visible version of Patrinia here:

http://www.ultraviol...c/182-patrinia/

For the UV version, I add BR-3 adapter onto the now reverse-mounted K2 to attach U-360/BG40 filter pack.

Here are the images of my adapter:

The parts used for the makeshift adapter:


JML 50/3.5 attached, K5 beside the combo:


BG40 is added to show the inside of the adapter/JML/K5 combo:

[nfoto]

To spare other people from wasting as much time as I had to do myself, next time you see strange blurs like this from your UV-capable lens:
(ie. not the usual blur circles but something odd like a flying swallow): do NOT despair. Your new, modified camera is NOT to blame.


(D600 modified by Lifepixel.com, UV-Nikkor lens and PN-11 to give 1:1 life-size magnification)

The problem is caused by a component being slightly angled off the optical axis. In my case, I employed a heavily used PN-11 extension tube for my UV-Nikkor. Turned out deep inside the assembly there was an inner sleeve held in position by three (under-dimensioned) screws and they had worked loose so the PN-11 did not hold the heavy lens properly aligned. After restoring the PN-11 to its former glory, I got my usual circular blurs again.

[Andrea B.]

So the UV-Nikkor central axis was not being held orthogonal to the plane of focus ??

[nfoto]

The tilt angle was small, but evidently sufficient for the strange blurs to appear. After spending an hour fixing the PN-11, I just reran a deep stack comprising 135 frames and could not detect any problems. Same UV-Nikkkor and PN-11 as last time.

[Andrea B.]

Glad to hear the problem is solved !!