Optima QB5

[photoni]

These days I was considering buying some Chinese filters to replace the Jena Glass BG25 and BG18 that I broke. I have seen that Tangsinuo uses Optima charts from the Optima website (optima-usa.net/80). I downloaded both the graph and the PDFs. There are big discrepancies. Do any of you have QB5 and QB29 and measured them?
I was excited to use the QB5 (yellow line) instead of the QB29 + QB39 stack to emulate collodion - wet plate.
Thank you -
Toni

 

GRAPH

 

.PDF

[colinbm]

The Chinese filters are what they are , but never what they say they are !
Their goal might be to imitate Schotts or Optima, but in reality they aren't.
You need to take your own measurements & use them for what they are worth.
They will be quite different to the graphs they show.
If you want the Schotts graph, buy Schotts. If you want the Optima graph buy Optima.

[photoni]

18 hours ago, colinbm said:

The Chinese filters are what they are , but never what they say they are !
Their goal might be to imitate Schotts or Optima, but in reality they aren't.
You need to take your own measurements & use them for what they are worth.
They will be quite different to the graphs they show.
If you want the Schotts graph, buy Schotts. If you want the Optima graph buy Optima.

 

Colin say wise things
BUT ... on the Optima page there is a graph (of the QB1-QB2-QB3-QB4-QB5) which says that the QB5 is blind from 500 to 1000nm
the graph file QB5.pdf (blue) says a different thing, which is blind from 510 to 680 nm and then sees more 10% of the IR

 

I ask if anyone has tried or measured it

Thank you

Toni

 

P.S. the two graphs Optima of QB29 are similar but not identical

all Schott filters have the same diagrams

 

[photoni]

Thanks @colinbm

Probably Optima's chart of the five types of QB is wrong  :(((

Optima QB5 PDF is right

i checked the homolog Hoya = B440, it is NOT similar ... unfortunately it does not cut red and IR

 

maybe i will buy a chinese filter and hope for luck

 

[photoni]

today ... after 1 year of searching for graphs :-)

I ordered filters from Jason for "my collodion emulation"

He only has a BG39-like Filter,  QB39 1.5 thick , I pointed out that he doesn't cut reds well (see yellow scum)
Jason recommended the TSN575 to me
has anyone used it?

 

Thanks

Antonio

 

(he does not have a filter similar to the BG40 2mm ø52)

 

 

[dabateman]

Never heard of it before. 

But the description curve here looks ok:

https://www.ebay.com/itm/IR-Cut-Filter-TSN575-stacking-with-ZWB1-ZWB2-for-UV-photography-/275226575209?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=711-127632-2357-0

 

Seems to only be available in 52mm mount. I might be interested in 77mm or 72mm. But not for a long time. Out of money now.

[photoni]

Yes @dabateman the red curve I got from his graph
I ordered it ø52
gave me a discount for 10 filters, I spent less than a Baader ... but more than my battered Sony A7 :)))
the only thing i would like in the future is a S8612 @ 52 - 2mm

[Yves W]

Thank you very much, I just ordered it, I am not satisfied with the QB39=BG39 from Tangsuino.

S8612 52mm - 2mm is difficult in Europe

[photoni]

TSN575 ... looks very good, but cuts a lot of UV.
Yes @Yves W buying S8612 in the USA with shipping to Europe + customs taxes costs twice as much

 

[Andy Perrin]

TSN575 cuts so much UV (and there is so little UV in sunlight) and passes so much visible that you probably will mostly see the visible light.

[photoni]

yes @Andy Perrin , it's true, the TSN575 cuts reds and IR very well, but it cuts too many UV.
Jason recommends it with ZWB1 & 2 but I believe it is a very dark stack, which will only pass 1% light.

As I showed in the graph, with the filters that interest me (QB29 and ZB2) S8612 or BG40 would be better.

 

Before breaking it I used a Jena glass bought in Germany without specs and without graphics, similar to BG18 it worked better than the Chinese QB39 <<<

 

I was re-reading this ...

 

 

[Yves W]

QB39=BG39 Tangsuino is not very bad with ZWB1 and ZWB2.

But it is bad with the ZWB3, ZB1, ZB2 and QB29. I have 2 other Chinese BG39 much better with these filters. 

The one that comes with the Kyoei Kuribayashi 35 F3.5 (clone) is good.

I am mainly looking for insect vision with the ZWB3

 

[photoni]

@Yves W I ordered filters ø52 - TSN575 - QB39 - QB29 - QB5 - ZB2 - ZWB3 (+ ZWB1 and 2 out of curiosity)
I took some rolls of Ortho and IR photographic film, in 120 format
We'll see what comes out

[Yves W]

Photoni, thank you

I don't have the QB5 in stock or on order,

I have the others and the Baader U since 2011

 

[Yves W]

Photoni you found the QB5 in 52mm, I'm looking but I can't find it. Thank you for your help and thank you for your very interesting tests.

[photoni]

Thanks @Yves W the QB5 I bought from Jason with 82 diameter, it is the only one available, it does not cost much
Similar glasses are: Hoya B-440 and Schott BG28

[Yves W]

Thank you @PhoToni, I had seen it in 82, it exists in 50 or 67 but naked.

[Yves W]

I asked Jason for the QB5 in 52mm. It is available since this morning, I ordered it

[photoni]

"real" result with Sony A7 + Meritar 50 mm with the diffraction grating and flash light

 

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[Yves W]

Thank you very much Antonio,

I received and tested the QB5 in 52mm. I also have ZB1, ZB2 and QB29.

For UV+B+G (near IVS), I like the ZWB3 with the TSN575.

During the winter, I have fun with the Vivitar 283/285 HV and Canon 199A flashes.

[photoni]

4 hours ago, Yves W said:

Thank you very much Antonio,

I received and tested the QB5 in 52mm. I also have ZB1, ZB2 and QB29.

For UV+B+G (near IVS), I like the ZWB3 with the TSN575.

During the winter, I have fun with the Vivitar 283/285 HV and Canon 199A flashes.

 

I would like one between QB5 and QB29; there is too much gap between the two.

:- )

[Yves W]

I like the ZWB3, I have very variable or even capricious photos on the others.

[photoni]

The sun inside an oxidized ZWB3

 

I have tried everything to clean the filter
with Kodak liquid, with Eclipse liquid, with nitric acid 10% with sulfuric acid 40%.
Things don't change, the surface looks dull.

Some photos taken with the Nikon Z7 (46 Mpx) +S 105 macro at maximum 1:1 magnification

show some corrosion, impossible to remove

(perhaps it should be polished with cerium oxide which I don't have)

 

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Photo with Sony A7 f.s. + Soligor KA 35mm @ f8  + only ZWB3 (~ UG5)

are dreamlike

(at f3.5 they are very flow)

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[Yves W]

Toni, I discover the same problem on my 2 ZWB3

[Andrea B.]

I would like to ask Toni, Yves, how long you had the ZWB3 filters before they began to deteriorate?

 

I was thinking that perhaps we should recommend that any uncoated filters be given an H2O2 bath at least once a month? 

 

Eventually a filter degrades past the point of reasonable use. I have a Baader Planetarium blue bandpass filter that I can no longer clean up. I will have to toss it.