Hello from Austin TX (Bernardo)

[bsas]

Hi all!

 

I just got my Sony NEX-7 converted to full spectrum and I am just in love with the whole exploration and learning process. I already played with the "classic" Hoya R72 infrared filter and a bunch of common Hoya color filters, like the RED (25A), YELLOW (K2) and the ORANGE (G). I settle all my filters to 58mm since it works really nice with all my lenses and I just need a couple of step down and step up rings.

 

Now, I really want to make UV work. First I tried to buy cheap ZWB1 and ZWB2 filters from China, but, quickly I learned that there is A LOT of infrared leak and I just cannot get the expected results (the classic "sunscreen" test :D). I am not even sure if those are really UV filters or just strong NDs or IR filters since there is no way for me to test them properly. I tried to "cut" some of the IR stacking cheap Hoya blue filters (80A, 80B, and 80C) but doesn't look like it worked that well.

 

Also, I am not sure if the lenses I have are good for UV. I have a collection of old Takumar M42 lenses and I believe that my 35mm f4 is good (I read that somewhere) but I don't have a step up ring for it yet. I have a Voigtlander 58mm f1.4 that I hope it is good but since I don't have my filters figure it out yet I don't know if my test makes any sense.

 

Lastly, I don't think I am ready to fully commit to a "Baader-U" price tag yet since I am not sure if I will be fully committed to the UV craft to justify it.

 

Then, my current situation (and I fully open to suggestions) is what is the cheapest way to get started. I am OK to stack and to find old filters and old lenses on pawn shops and eBay. Also, I am looking at this eBay product but I am not sure if it works and if this company is trust worthy:

https://www.ebay.com/itm/58mm-UV-Short-Pass-Filter-for-UV-photography-How-Sun-See-You-black-sunscreen/192846388168

 

Thanks all, I am super excited to be part of the group! :D

[Andrea B.]

Hello Bernardo and welcome to UVP! We hope you enjoy the website and find lots of good information.

 

Yes, the ZWB filters are not ready for prime time just yet. There is too much variation because of so many different manufacturers. And there does not seem to be a good effort by them to suppress all visible light leaks which contaminate UV photos. Their IR passage can sometimes be dealt with by stacking with some blue-green filter glass.

 

For our best effort in filter recommendations (and some vendors), please see the Filter Sticky in the Reference section. There are 7 good UV-pass filter choices listed there: BaaderU, KolariU, LaLaU, AndreaU, LuvU2 and SEUGen3 and a Stacked (dual bandpass + blue-green). Also you can use the filter search tag to read more about member's experiences with various filters.

There is no ideal choice. Each type of UV-pass filter has its pros & cons.

Sticky :: UV/Vis/IR Filters

Filters.

Reference Section

 

Your Sony NEX-7 will be a good conversion which should last you a long time. I have the Takumar 35/4.0 and it is good in the upper half of the waveband from about 350 - 400 nm (approximately), a nice little lens. Check the Lens Sticky for more such examples. Old enlarger lenses are also good choices to get started with as long as you don't mind having to kit them up with focusing helicoids and front rings.

Sticky :: UV-Capable Lenses

[dabateman]

I don't get a good feeling from that seller. I bought a BG40 from them and it was badly scratched. They did exchange it for a correctly new one. But over all I think people have mixed opinions.

 

Your cheapest solution would be to get a S8612 2mm filter from a reputable seller.

Here is a link to one in your size:

https://www.ebay.com/itm/Schott-S8612-58mm-x-2mm-UV-IR-Cut-Filter-Visual-Bandpass-IR-Suppression/293120993582?hash=item443f5f692e:g:wVAAAOSw94FdA8vp

 

Your ZWB1 and ZWB2 filters maybe good. But you have to stack them with a good IR blocking filter, like the one I linked. The S8612 is expensive, but can be used stacked with other UV filters like UG1=U360 like ZWB2, UG11=U340 like ZWB1, UG5=U330 like ZWB3, or BG3 like B370.

 

I was lucky with mine ZWB1 and it transmits better than a similar U340 filter, but does let through more IR. So a good 2mm IR blocking filter maybe needed.

[Andrea B.]

I'd just avoid ZWB for now. If you buy cheap leaky filters, then you will probably get poor results and eventually you will want to spend the money for a good UV-pass filter that you should have spent in the first place.

 

The proliferation of this bad UV-pass filter glass really irks me off. Even worse is when some vendors try to pass it off as real Schott or Hoya filter glass.

OK, sorry!! Rant over. I just don't like to see my UVP friends getting cheated by bad quality control and/or bad glass formulas.

[Andy Perrin]

Yeah, I have some deliberately mislabeled Chinese QB glass that I don’t use for anything. It came free with my conversion of my old NEX-7 so at least I didn’t pay. I was quite happy with the NEX-7 and only replaced it to go full frame with another Sony, the A7S, which I also mostly love, although the user interface is often annoying. I use Schott filters now (S8612 and UG11) that I bought from Cadmium in his other incarnation as “UVIR Optics” on eBay. I have been happy with them.

[ulf]

I don't get a good feeling from that seller. I bought a BG40 from them and it was badly scratched. They did exchange it for a correctly new one. But over all I think people have mixed opinions.

 

Your cheapest solution would be to get a S8612 2mm filter from a reputable seller.

Here is a link to one in your size:

https://www.ebay.com...VAAAOSw94FdA8vp

 

Your ZWB1 and ZWB2 filters maybe good. But you have to stack them with a good IR blocking filter, like the one I linked. The S8612 is expensive, but can be used stacked with other UV filters like UG1=U360 like ZWB2, UG11=U340 like ZWB1, UG5=U330 like ZWB3, or BG3 like B370.

 

I was lucky with mine ZWB1 and it transmits better than a similar U340 filter, but does let through more IR. So a good 2mm IR blocking filter maybe needed.

 

I do not trust Image-Laboratory, your suggestion either. I got BG40 two times, that was suposed to be BG38. One of them was not really flat over the entire surface.

 

I second almost all Da Bateman say, except that I think you should go for 52mm as filter dimension for UV. It keeps the costs down and there are much more filter types available.

For a S8612 go for 2mm thickness to get enough IR-attenuation to work well with many different lenses.

 

Most UV-capable lenses do not need anything bigger.

Fast lenses with wide front lens-elements often have too much glass in their optical path that block UV too much to be usable.

Most of the M42-lenses that work are f/3.5 or slower.

[bsas]

Thank you all for your feedback, I am super excited to start! :D

 

So, I have another question, you guys suggested an "blue-green filter glass" as a cheap "IR block" filter. Any specific suggestion like an specific Hoya model or another affordable brand like B+W?

 

I am confused since in theory the blue filters (80A, 80B, and 80C) show block IR according to their chart:

 

Am I missing something or 20% transmittance is enough for the IR to overpower the UV light?

 

Thanks again! :D

[Andy Perrin]

20% will blast the UV out of the water. Even 1% will. You need to block to OD4+ at least, which is 0.01% or it will still be clouding the dark areas. This is why we use the diabatic charts (the ones that look sort of like logarithmic charts but not quite). The linear charts are very misleading.

[Andrea B.]

The best blue-green IR blocker (as mentioned in the Filter Sticky) is S8612 in a 2mm thickness.

[ulf]

Thank you all for your feedback, I am super excited to start! :D

 

So, I have another question, you guys suggested an "blue-green filter glass" as a cheap "IR block" filter. Any specific suggestion like an specific Hoya model or another affordable brand like B+W?

 

Cheap in cheap "IR block" filter is a very relative term.

You'll need a specialist filter to get enough blocking.

There are no filters from the normal brands like Hoya , B+W... that will work.

 

Then buy one of these:https://www.ebay.com...=item23925a087a

This filter work without needing any additional filtering of IR and is filtering almost as good as the expensive Baader U filter.

https://www.ebay.com...CYAAOSw7ApdBrEE.

 

You could possibly mount the filter with some kind of putty on the rear of the Takumar 35/4.0 lens.

Then make the mounting light tight, to avoid any light passing around the filter.

 

To make handling the filter easier (it's just a coated glass disc), you could get a small 27mm UV-filter and replace the clear glass with the special filter glass.

[dabateman]

If you decide to go with the 25mm filter, you can message the seller before you buy it to get it mounted into a 28mm filter. This will cost a little extra, but if you are not comfortable mountung it yourself. It can safe you from breaking it or scratching the coating.

 

Even 25mm filters will work with a Canon APSc which is nearly the same sensor size as 43rds. I don't have any issues with these on a 43rds camera. Most UV capable lenses seem to have small front lens element diameters, which helps.

 

[ulf]

If you decide to go with the 25mm filter, you can message the seller before you buy it to get it mounted into a 28mm filter. This will cost a little extra, but if you are not comfortable mountung it yourself. It can safe you from breaking it or scratching the coating.

 

Thank you David.

That is good to know for my future purchases there.

[bsas]

Then buy one of these:https://www.ebay.com...=item23925a087a

 

To make handling the filter easier (it's just a coated glass disc), you could get a small 27mm UV-filter and replace the clear glass with the special filter glass.

 

Do you guys know if any vendor sells those "better" IR cut filters, like this 330WB80 one but as a Sony E clip filter (to put inside the camera in front of the lens itself?

[Andy Perrin]

Nope, and they come in 25mm circular sizes, which probably is the wrong shape for a clip in. That filter is not just an IR cut, though, it's a dichroic UV-pass filter like the Baader that simultaneously blocks IR pretty well, so you only need the one filter, not a stack. If you want to put one on the back of the lens, I use 3M poster putty for temporary attachment to the rear of a lens. It does make it hard to switch filters, though.

 

Unfortunately, the world of UV photography isn't as slick and streamlined as the IR side. We are a very tiny hobby, adapting equipment made for other purposes mostly, so there isn't the variety of equipment that works off-the-shelf that you get with IR.

[residentbrit]

Hello Bernardo, welcome, I just joined myself, I am in a similar boat, waiting for my Canon 60D to return from full spectrum conversion, I have some m42 lenses that I think will work, plus a canon pancake lens that has been reported to work pretty well for UV. I'm just trying to decide on filters now, I'm thinking of on the lens filter stack 52mm thread mount, the Schott UG11 or 1 and S8612.

[bsas]

Hello Bernardo, welcome, I just joined myself, I am in a similar boat, waiting for my Canon 60D to return from full spectrum conversion, I have some m42 lenses that I think will work, plus a canon pancake lens that has been reported to work pretty well for UV. I'm just trying to decide on filters now, I'm thinking of on the lens filter stack 52mm thread mount, the Schott UG11 or 1 and S8612.

 

Hi and welcome! :D

 

I honestly recommend to buy cheap Hoya color filters together with the "classic" Hoya R72 one just to play with. The RED (25A) is very cool for infrared false color and close to the LifePixel Enhanced (665nm) and the YELLOW (K2) is similar to LifePixel Hyper Color (470nm) as you can see on the chart bellow. Not exact, but good enough to play, and those filters are very easy to find super cheap on eBay :D

 

Before diving into the UV, play with the Full Spectrum itself (it is so cool) and infrared since it is quite easier than UV so that makes you pumped and ready to go to the UV route which is harder but crazy cool! :D

[residentbrit]

Thanks Bernardo, interesting info, appreciate it, it's certainly worth considering, I'll check it out.

[Andrea B.]

Yes, with a full spectrum camera you can get all kinds of interesting and wild results with longpass filters! Fun and weird cool results. Also interesting to try are such filters as BG3 which is some combo of IR and blue. Or try the dual bandpass U or UG glass without an IR blocker to get cool combos of IR and UV -- mostly IR comes through, but just enough UV to give unusual false colours.