UV transparent resin or glue?

[Avalon]

Does somebody did ZWB and high quality Schott filter photo comparison? There is bigger difference between QB21 and S8612 or BG40 than ZWB and UG. ZWB2 doesn't transmit UVB and UVC but has best of all ZWB glass UVA tranmission, especially in range 365nm that's choice of my filter. Besides I can get into deeper UV since I still use glass optics and wont be debayering sensor.

[Andy Perrin]

The problem is that the ZWB curves you find online are not trustworthy. They have such poor tolerances that every individual filter is different from each other, and different from the nominal curves. So a comparison is impossible -- you would only be comparing that particular ZWB filter.

[Cadmium]

Does somebody did ZWB and high quality Schott filter photo comparison? There is bigger difference between QB21 and S8612 or BG40 than ZWB and UG. ZWB2 doesn't transmit UVB and UVC but has best of all ZWB glass UVA tranmission, especially in range 365nm that's choice of my filter. Besides I can get into deeper UV since I still use glass optics and wont be debayering sensor.

 

As far as I know, there is no brand of filter glass that is equivalent to Schott S8612. It transmits UV deeper, and suppresses IR stronger than any other.

There are some that are equivalent to BG39, which has a similar curve to S8612, but doesn't transmit as deeply in UV as does S8612.

There are some that are equivalent to BG40 and BG38, but you would need to use fairly thick BG40 to suppress as much as S8612, and you would not want to use BG38 for UV stacking, just for visual usually.

S8612 2mm very similarly equivalent to BG40 4mm (for example, compare green line with purple line on graph below, or blue line with amber line).

 

= means equivalent

~ means kinda maybe but not really equivalent

 

Schott UG11 = Hoya U-340 ~ China ZWB1

Schott UG1 = Hoya U-360 ~ China ZWB2

 

China glass is less efficient, resulting in longer exposure time needed for UV stacks using China glass.

I did a test comparison, let me see if I can find it... hold on, stay here, wait a minute... please press 1 if you would like to listen to music while you wait...

Here is the test that I did, notice how much longer the exposure time is needed for the ZWB1 stack, and it is still dark.

http://www.ultraviol...__fromsearch__1

 

Here is a nice comparison test that Andrea did:

http://www.ultraviol...__fromsearch__1

 

There are many topics here that talk about ZWB1, etc., so just search for "ZWB1".

 

[Avalon]

I see now that perks of expensive filters is mainly in higher transmission of UV spectrum and thus reducing need for exposure time or increased sensitivity, or UV illumination. Cheap filters however can block infrared or visible light just by increasing thickness, of course UV transmission also somewhat suffers. For outdoor photography non chinese filters are best option but for now I going to use cheaper filters. I plan to do more still photos of paintings so I can use tripod and control ultraviolet illumination amount.

 

Looks like ZWB1 is really better to cut out visible light although I'm concerned that some deep red may leak so thicker or stronger infrared suppressing filter is needed in stack. I plan to use thicker 2mm ZWB1 filter instead of 1,5mm. Here is seller provided spectrum of filter in numbers:

The transmission data for ZWB1 with 2mm thickness as below:

1100.00 1.3

1095.00 1.3

1090.00 1.3

1085.00 1.3

1080.00 1.3

1075.00 1.3

1070.00 1.2

1065.00 1.2

1060.00 1.1

1055.00 1.1

1050.00 1.0

1045.00 0.9

1040.00 0.8

1035.00 0.8

1030.00 0.7

1025.00 0.6

1020.00 0.6

1015.00 0.5

1010.00 0.5

1005.00 0.4

1000.00 0.4

995.00 0.3

990.00 0.3

985.00 0.3

980.00 0.2

975.00 0.2

970.00 0.2

965.00 0.1

960.00 0.1

955.00 0.1

950.00 0.1

945.00 0.1

940.00 0.1

935.00 0.1

930.00 0.1

925.00 0.1

920.00 0.1

915.00 0.1

910.00 0.0

905.00 0.0

900.00 0.1

895.00 0.1

890.00 0.0

885.00 0.0

880.00 0.0

875.00 0.0

870.00 0.0

865.00 0.0

860.00 0.1

855.00 0.1

850.00 0.1

845.00 0.1

840.00 0.1

835.00 0.1

830.00 0.1

825.00 0.1

820.00 0.1

815.00 0.2

810.00 0.2

805.00 0.2

800.00 0.3

795.00 0.4

790.00 0.5

785.00 0.6

780.00 0.8

775.00 1.1

770.00 1.5

765.00 1.9

760.00 2.5

755.00 3.3

750.00 4.2

745.00 5.4

740.00 6.8

735.00 8.5

730.00 10.4

725.00 12.3

720.00 14.0

715.00 14.8

710.00 14.6

705.00 13.5

700.00 12.4

695.00 10.9

690.00 8.5

685.00 5.8

680.00 3.6

675.00 1.9

670.00 0.8

665.00 0.3

660.00 0.1

655.00 0.0

650.00 0.0

645.00 0.0

640.00 0.0

635.00 0.0

630.00 0.0

625.00 0.0

620.00 0.0

615.00 0.0

610.00 0.0

605.00 0.0

600.00 0.0

595.00 0.0

590.00 0.0

585.00 0.0

580.00 0.0

575.00 0.0

570.00 0.0

565.00 0.0

560.00 0.0

555.00 0.0

550.00 0.0

545.00 0.0

540.00 0.0

535.00 0.0

530.00 0.0

525.00 0.0

520.00 0.0

515.00 0.0

510.00 0.0

505.00 0.0

500.00 0.0

495.00 0.0

490.00 0.0

485.00 0.0

480.00 0.0

475.00 0.0

470.00 0.0

465.00 0.0

460.00 0.0

455.00 0.0

450.00 0.0

445.00 0.0

440.00 0.0

435.00 0.0

430.00 0.0

425.00 0.0

420.00 0.0

415.00 0.0

410.00 0.0

405.00 0.0

400.00 0.0

395.00 0.4

390.00 3.0

385.00 12.6

380.00 28.8

375.00 46.6

370.00 60.5

365.00 70.6

360.00 76.2

355.00 79.4

350.00 81.5

345.00 82.8

340.00 83.7

335.00 84.2

330.00 84.3

325.00 84.2

320.00 83.8

315.00 83.2

310.00 82.1

305.00 80.6

300.00 78.3

295.00 74.7

290.00 70.3

285.00 64.3

280.00 57.1

275.00 48.4

270.00 37.8

265.00 27.1

260.00 16.7

255.00 8.0

250.00 2.4

245.00 0.4

240.00 0.0

235.00 0.0

230.00 0.0

225.00 0.0

220.00 0.0

215.00 0.0

210.00 0.0

205.00 0.0

200.00 0.0

[Andy Perrin]

Avalon, you should stick that in a CSV file and link it from Google Drive or Dropbox.