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UltravioletPhotography

Filter wheel and Baader U size.


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I'm going to be joining you guys as a real UV photographer very very soon.I might have missed a lot of flowers this year but there are lots of other things I want to explore in UV. I have a 80mm El-Nikkor in my hands and have decided to use a La La U by UVIROptics as my UV pass filter. I have that ordered and on the way. I'm 3D printing up lots of adapters and do hickies for exactly what I want. If they work well I usually publish them on thingiverse.

 

One design I might revisit is this filter wheel I did a while ago. https://www.thingiverse.com/thing:2962128 I'll make the sockets deeper so it can accept thicker filters like some uv filters.

 

Does anyone have precise external dimensions for the Baader U? I'll make a little adapter for it for you guys if there is interest.

 

The filter wheel serves two purposes. the first it it lets you change lenses faster than screwing and unscrewing them. Next it protects the filters. Less wear and tear on the threads and there is some drop protection by being encased in two layers of plastic. Less likely to drop in the first place because you not screwing and unscrewing.

 

Is there any interest in this filter wheel? Is 52mm what most people here are using? Any interest in a simpler 3 or 4 position wheel? Put your IR pass filter in one position, a UV-IR cut in another, and your UV pass in the last position.

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That looks very cool! I have always wanted to set up a filter wheel for 52mm filters.

I have never got one or tried one.

I have always wondered about the possibility or tendency for light leaks with such an apparatus. I don't know how well they would block light leaks in the day time.

Your model looks very nice.

I think this would be a great discussion in general, because there are probably a lot of questions about these from people who have never tried one,

and there are a lot of reasons someone might want to use on in the multispectral community...

So yes, I am definitely interested in the topic. I know virtually nothing about them, so al am all ears.

 

I have a Baader U, so let me know if you want me to measure something from it.

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Thanks. I haven't seen any light leaks doing trichromy and infrared with it.UV would be a bigger test.

 

What I need on the Badder is just a use a set of calipers on it and tell me what the external diameter is. What the depth of the filter casing is. How much of that is threaded M48.

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I can see light leaks in your prototype photos.

A lot of even black plastics leak IR & a lot of plastics fluoresce in UV light.

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I can see light leaks in your prototype photos.

A lot of even black plastics leak IR & a lot of plastics fluoresce in UV light.

 

Are you talking about the second picture with light leaks? Those aren't on the picture taking lightpath path. If you want a gasket on the picture taking light path I could do that. I'd probably use black felt that doesn't florece.

 

As far as plastics I have seen those as well.I had some black PETG was not black in IR. The white body I have on now does fluoresce under UV. I guess A- that plastic gets replaced in version 2 and B-the white parts were never part of the picture taking light path.

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I wonder if carbon fiber impregnated plastic would be suitable ?

 

I generally don't like those. They are not as tuff as engineering grade PLA/PLA+ and they eat away the printers nozzle with abrasive action.

 

All the black plastic on the filter wheel is Hatchbox black that performs about as well as engineering grade stuff. It can even be thermally annealed to be tougher but with some loss of dimensional accuracy.

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Great idea to 3d print a filter wheel. I have been slowly playing with a 1.25" filter wheel that I still haven't used yet. Took a long time to get things together and have been extremely busy since March.

I also acquired a super cheap 25mm filter wheel from ebay from a seller whom didn't know what it was. Was full of odd IR filters, and was most likely surplus from silicon wafer fabrication place. Still have to test the filters to understand the rationale.

 

The critical factors will be registration distance or if in front, the vignetting.

The seal and materials will be trial and error I think for you.

 

Do you have a BaaderU filter?

 

They are really thick and in 48mm holder. If you don't plan to use one, I would bother trying to generally make a file. There are many factors to adjust for that you would need one on hand.

 

Cadmium solved some by remounting the filter into step rings for thin profile. I have gone thick with extra rings and step rings, as use four thirds system and rather have flare protection.

 

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Photos of my Baader U installed in different ring to fit 52mm.

My Baader U original ring is 7mm high (excluding the rear threads), and the usual 48mm threads.

The Baader U filter glass is removed and put in a 52mm to 48mm step-down ring, with a 48mm retaining ring behind and in front of the Baader filter glass.

If you want to install any 52mm filters or hoods in front of the 52mm mounted Baader U, then I add a 48mm to 52mm step-up ring.

Overall, the two rings are 7mm but allows for direct 52mm on both sides with no added conversions or thickness (height/tall).

For those worried about the Baader U color in these pics, the color here is deceptive in these shots due to the lighting or reflection.

I have the 'gold side' facing out and the 'copper side' facing in toward the camera lens.

 

post-87-0-32031600-1590603683.jpg

 

post-87-0-48757000-1590603701.jpg

 

post-87-0-47930100-1590603712.jpg

 

Older photo showing retaining rings positioned too far forward, leaving inadequate front threads for attaching any filters or a hood.

post-87-0-32845300-1590603811.jpg

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I get:

 

Diameter: 49.55mm

Diameter across outside of threads 47.86

Thickness including threads: 8.05mm

Thickness not including threads 5.96mm

 

The precision is about +/- .03mm

This instance was purchased in June 2019 from agenaastro on Amazon

It is my understanding that the thread pitch on the manufacturer supplied ring is not the same as on camera rings

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With my calipers I get:

 

Diameter: 49.47mm

Diameter across outside of threads 47.80

Thickness including threads: 9.68mm

Thickness not including threads 7.60mm

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Another nice thing about having a filter wheel is that it makes for easy portability of several filters. The wheel with filters could perhaps be carried in a zippered case like used for ipads or small laptops. I'm liking the idea. My only question would be whether a filter in the wheel could be properly fitted to the lens so that no light leakage occurred??
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I'm using a metal drawer system (rear-mounting filters for my Z system) and light leaks can easily be introduced unless one is very careful and shut and lock the drawer properly.
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