Nikon D7100 modified with Standard lens for UV

[kogakunippon]

Hi,

 

did anyone ever try to use the 18-55mm Standard Nikkor lens for ultraviolet? I read all articles from Dr. Savazzi and Dr. Schmitt about the difficulties and found many dedicated UV-lens here at the great forum. So I know about the problems shooting UV very well.

 

Anybody.....?

 

Kind regards

 

Wolfgang

 

Original file from my Nikkor AF-S DX 18-55mm f/3.5-5.6 G VR II at 18mm with an S-8612 plus Baader U-Filter in 2" (just resized from the original NEF File)

[Cadmium]

Hi Wolfgang, It looks good!

You are stacking the Baader U with the S8612 ? You don't need to stack the Baader U with anything, just use it by itself.

The 18-55mm VR is my favorite lens for almost anything except UV, it doesn't transmit very deeply into UV, it doesn't have as much false color.

How did you white balance this? If you are using a Nikon, then I like white balancing with Nikon NX2 or NX-D software from RAW files.

Video #5

https://www.lifepixe...hotoshop-videos

[nfoto]

Most 'normal' lenses will cut ever so slightly into the upper UV band. Sometimes this is enough to indicate UV signatures of flowers.

 

It is just a matter of pushing enough light through the lens. However, the UV image captured often is troubled with severe focus shift, low contrast, or poor resolution, thus finding a lens that transmits UV better is always desirable. Focus shift is common also to those lenses, though, thus using LiveView for critical focusing is to be preferred if possible.

[kogakunippon]

Thanks for your answers.

 

@Cadmium:

I was not sure if the Baader U-Filter has a leakage in the infrared wavelengths, thats why i was using it. Are you sure that the Baader U-Filter is blocking the whole range from 400nm till 2000nm, even with modified Camera Body?

 

@Bjorn:

I understand well what you mean when you said "...just a matter of pushing enough light through the lens!". But that implies that the exposure time with this 18-55mm Standard lens should have been longer then with my Noflexar 35mm F3.5 lens, which isn't true. Both lens needed exactly the same exposure time with thoose two filters on it. Is it possible that the variety of pressed plastic lenses in the lens allow better transmission in the range of UV Radiation?

 

The Focus shift is a Problem thats true, but the positive thing is, that the Nikkor 18-55mm offers a 18mm (24mm in FX) with a 52mm filter thread. And with my UG-11 instead f the Bader U there is no vignetting either!!

 

Thanks,

 

Wolfgang

[enricosavazzi]

[...]

I was not sure if the Baader U-Filter has a leakage in the infrared wavelengths, thats why i was using it. Are you sure that the Baader U-Filter is blocking the whole range from 400nm till 2000nm, even with modified Camera Body?

[...]

An earlier Baader U (perhaps 5 or more years ago) had a small but occasionally troublesome IR leak. The current Baader U (sometimes called U2, but this is not an official denomination by the maker) is better in this respect. There might still be unsold specimens of the first-generation Baader U in some astronomy shops or in the drawers of some users, so the old version might still pop up occasionally on eBay.

[kogakunippon]

I got my one directly from the Baader Planetarium two weeks ago, so I hope ist the 2nd Version. ;-)

But thanks for the Information.

 

Wolfgang

[Cadmium]

Hi Wolfgang, Yes, you have a new version, you don't need to stack anything with your new Baader U.

[kogakunippon]

Thats a great Information, thx Steve. ;-)

 

What still makes me suspicious is the fact that the standard lens lets through the same amount of UV light as the Noflexar.

[nfoto]

Do a comparison against e.g. a Noflexar, then white-balance the capture with your kit lens. It can look pretty decent. Now, in Photo Ninja or equally capable raw conversion program, paste that white balance onto the Noflexar capture. The false colours now will look completely different and you probably observe a very strong yellowish cast.

 

This exercise tells there is more to UV photography than exposure times alone (and you are certain the Noflexar was stopped down properly - easily forgotten with its strange preset aperture mechanism - done that myself on occasion...).

[Cadmium]

Wolfgang, Something else I am curious about here is the vignetting,

the size of the reduced frame makes me wonder what diameter your Baader U is, or perhaps this is because of the added S8612 stack or how the filters are adapted to your lens.

I have a D7200 here, 18-55mm VR lens (yours is the VR II), and no vignetting @18mm with my Baader U (at least the way I have mine mounted).

So if that is a 48mm Baader U, then you should be able to mount it in such a way as to not experience any vignetting, even with that lens.

 

I don't have my Baader U mounted in the original frame/ring, here is how I have mine adapted.

This uses a 48mm-to-52mm step-down ring, using two 48mm 'retention rings', one in front and one behind the Baader U glass to hold it in the step-down ring.

This arrangement needs a 48mm-to-52mm step-up ring in the front if you want to stack any 52mm filters or a hood. This older photo shows no thread space in front of the Baader U,

but the glass can be positioned further back in the step-down ring, by adjusting the two 'retention rings', which will give you more front threads for attaching a hood, etc., which is how I have mine adjusted now.

[kogakunippon]

Hi Steve,

 

that is a very cool idea, but I dont have thoose Retention rings, either don't know how to get the filter out of it's orignal Frame...??? Could you help me please with this? Thanks in advance.

[kogakunippon]

@bjorn:

 

Thanks for this advice, I will try it again and show the results then.

[Cadmium]

You can just use a 48mm-to-52mm step down ring and put the original Baader U in that, which is how I guess you have it mounted now, but with the S8612 either in front or behind the Baader U,

and removing the S8612 filter will remove at least some of the vignetting I would guess.

If you don't feel comfortable removing the Baader U from its original frame, then don't do it. I used a pair of scissor tips to unscrew mine, but you can use various tools for that. Be careful.

If you do remove it, then all you need is a 48mm-to-52mm step down ring, the one original 48mm retention ring from the Baader U (which I think I have in front of the Baader U glass), and another 48mm retention ring from some other 48mm filter/frame. This also gives you the chance to decide which surface of the Baader U you want facing outward, which is a whole other thing people get into discussing about the Baader U.

[Andrea B.]

Reversing the BaaderU has nothing to do with the UV capture. Reversal is done to help prevent flare and reflection rings from this very shiny filter. These artifacts occur with some lenses, not all.

 

So, the pink/gold side of the BaaderU should face the subject for best results with this filter.

 

Example: The BaaderU unreversed -- green side faces subject -- used with the Vivitar 35/3.5. Light source (sun thru window) at about 45° to front of lens. A large green reflection is produced with this lens. Unfocused subject.

 

 

 

This was excerpted from an older post: Breaking in the Sony A7R: Part One