Transmission through thin (0.5mm) Hoya U-340 and U-360 filters

[dabateman]

Or can we import the data in the Schott filter calculator program and use its diabatic plot?

 

(I'm not suggesting it is a better idea, it is just an alternative)

 

You can enter any data you want in the Schott spreadsheets. The last page has user data. That is were I have entered Cm500, u330, u340 and U360 data.

[JMC]

All,

I have sent the data through the forum message system - zip file with a couple of spreadsheets inside. Should be straightforward enough, but if you have any questions let me know.

 

I spoke with the suppler about the thickness of the filters. Turns out their spec is +/- 0.1mm, which I think is pretty common among manufacturers. Hence getting filters at 0.6mm is within spec for a request of 0.5mm. I suppose 0.1mm doesn't make much difference if it is already 2mm thick, but it has quite an effect on these thin ones.

 

Thank you all for helping to make this happen.

[Cadmium]

You can enter any data you want in the Schott spreadsheets. The last page has user data. That is were I have entered Cm500, u330, u340 and U360 data.

 

David, I believe you have to enter Ti data in the Schott program.

[Stefano]

You can enter any data you want in the Schott spreadsheets. The last page has user data. That is were I have entered Cm500, u330, u340 and U360 data.

I have already done that. I entered some Hoya filters, like U-340, U-360 and B-410.

[Stefano]

David, I believe you have to enter Ti data in the Schott program.

Yes, I think. My PC is not connected now, so I can't check, but I remember the same.

[ulf]

David, I believe you have to enter Ti data in the Schott program.

Correct.

[Stefano]

[a bit off-topic, but still related]

I noticed Hoya graphs are smooth, so they collected data at a finer resolution (like every nm) and used that to plot their graphs. I don't think they have data in the visible spectrum, especially if they measured their filters at 2.5 mm, but they should have finer data in the UV and IR regions, they just don't publish it. If what I said is correct, can we ask Hoya to provide us their data?

I did it. Yesterday evening Hoya replied me sending me their data for their U-340 and U-360 filters, in 1 nm resolution. The reference thickness is 2.5 mm, and the transmission is "External" (I guess T). I wanted to post this yesterday, but I had a "little problem" (I forgot my password. I didn't remember only one symbol, and the only copy I had of my password was on my iPad, which I didn't have because I sent it to be repaired. That's a bit embarrassing, I know).

 

...anyway, I want to underline a thing: the "holes" in the visible spectrum are still there. Jonathan's work wasn't useless, by any means. He provided us with information even Hoya doesn't have (or isn't interested in having).

Data for U340 and U360.zip

[Cadmium]

Stefano, Interesting! You still need Ti data to enter in the Schott program.

Hoya data sheets provide both T and Ti data, but as we know it is only for every 10nm, and no data at all for some ranges, which is still not provided in the 1nm data Hoya sent you.

I think what you got from them is the same data they have in their filter program. The only use I have found for their program is to export the data for entry into the Schott program,

simply because their program data is 1nm resolution, however there is still the non data drop outs, and some of the filter data they have in their program seems to have some errors.

They do provide T and Ti data with their program, but maybe not for all their filters, not sure.

It is pretty easy to export Ti data from the Hoya filter program to the Schott filter program, so you can gain resolution, but still no data for the visual range with U-360 and U-340.

Here again is an example of Hoya data entered manually from their 10nm resolution data sheet, and their filter program exported Ti data.

The main difference in the UV range is due to newer data I believe. U-360 B (purple line) = 1nm res from import, U-360 (red line) = 10nm res from data sheet. Sorry Andy, no dots on this graph.

[Stefano]

I think we can use Hoya's data in the UV and IR regions, and Jonathan's data in the visible region, since that's all we have there.

 

What surprises me more is that some members (including probably you and surely me) really wanted Hoya filters data in 1 nm resolution instead of 10 nm, and it was apparently as simple as asking Hoya. I wonder why I didn't do that before.

[Cadmium]

You don't need to ask Hoya, you can get it and export it from their program.

I think they got it from their program, and if you had asked them for Ti then they may have given you that from their program export also.

[Stefano]

Finer data is important for two reasons: you have a more precise peak (for example at 367 nm instead of 370 nm) and you have precise peak transmission, especially when the "tip" is flat instead of pointy in 10 nm resolution. You can underestimate it probably not by more than 5%, but it is still an underestimation.

[Stefano]

You don't need to ask Hoya, you can get it and export it from their program.

I think they got it from their program, and if you had asked them for Ti then they may have given you that from their program export also.

I didn't know you could get this data from there. Regarding Ti, they surely calculated it, as you cannot measure it directly (I think). Probably I should have asked for it, or for both, I didn't think about Ti specifically.

[Cadmium]

As I said, keep in mind that the difference in the plots and the peaks of that comparison graph is because they have updated their data sheets.

I have seen two data sheets out there now. One of their data sheets is the one I entered, the other data sheet is the data they have in their program (the purple plot line).

The difference in that comparison example graph has little to do with with the data resolution.

Does it sound like I am arguing against higher resolution data? No, I am not at all.

I am simply saying that you can get it from their program, both T and Ti, but it will not have the missing ranges of data.

 

https://hoyaoptics.c...lter-simulator/

[Stefano]

The difference between old and new data is interesting, at least I would have expected less. Newer data should be trusted more than the old one (?) Or maybe we should still give a look at their old data too?

 

Hoya doesn't give data in the visible region, and that was the purpose of Jonathan's work. As I said, he did an awesome job, and answered some questions I had. Hoya probably isn't even interested in the visual range of those filters, as they are rock solid there at their reference thickness (2.5 mm).

[Cadmium]

Here are the older and newer Hoya U-360 data sheets, you will find these in various places online.

 

Older Hoya U-360 data sheet:

https://www.sydor.com/wp-content/uploads/2019/06/Hoya-U-360-Ultraviolet-Transmitting-Visible-Absorbing.pdf

 

Newer Hoya U-360 data sheet (used in the Hoya program):

https://www.uqgoptics.com/wp-content/uploads/2019/08/Hoya-U360.pdf

[Cadmium]

My only point is that you can get the Ti data from the program.

[Stefano]

Here are the older and newer Hoya U-360 data sheets, you will find these in various places online.

 

Older Hoya U-360 data sheet:

https://www.sydor.com/wp-content/uploads/2019/06/Hoya-U-360-Ultraviolet-Transmitting-Visible-Absorbing.pdf

 

Newer Hoya U-360 data sheet (used in the Hoya program):

https://www.uqgoptics.com/wp-content/uploads/2019/08/Hoya-U360.pdf

Thanks. I remember the old ones, but they were more difficult to find after they released the new ones.

[Cadmium]

Interesting to note that even though the newer Hoya data sheet shows both red and blue plot lines for T and Ti,

the data sheet only provides the T data, and the Schott program needs to have Ti data entered, so it would need to be converted, which the Hoya program provides,

but their older data sheets provide both T and Ti data, which is how I entered it into the program (before the newer data sheets were around).

However, now you have to get the Ti data from their program, or you could convert it your self I suppose.

Just another reason why Schott provides much better filter data, and a much better filter program also. Schott is the best.

Other than U-360 (and a few price differences) I like Schott filters more than the Hoya equivalents, but there are also a few filter type Schott doesn't have, like B-410...

[Stefano]

I like the fact that the new curves peak lower. Hoya U-340 actually peaks at 332 nm, according to the data Hoya sent me. That makes it more similar to Schott UG11.

[Stefano]

I like Hoya U filters since they transmit more UV and less IR than their Schott equivalents (particularly U-360 vs UG1). Their downside is that they leak more visible light than Schott ones, I was particularly worried about Hoya U-340 leaking too much green but according to Jonathan's data it should be OD 5+ in the green at 1 mm (I still have to see his final Excel files better). S8612 is unbeatable, nothing as of today performs better than it.

[ulf]

I like Hoya U filters since they transmit more UV and less IR than their Schott equivalents (particularly U-360 vs UG1). Their downside is that they leak more visible light than Schott ones, I was particularly worried about Hoya U-340 leaking too much green but according to Jonathan's data it should be OD 5+ in the green at 1 mm (I still have to see his final Excel files better). S8612 is unbeatable, nothing as of today performs better than it.

I suspect that there is a risk that the filter performance in the Hoya-uncharted VIS-areas might vary from batch to batch.

 

One piece of information I hope Jonathan got from the supplier of the thin glasses is some way to identify the filter glass batches, like a melt number or similar.

The measured data is valid for that batch only and we do not know anything about the batch to batch variation.

[Stefano]

Ulf, yes, you are right. Both Hoya and Schott average hundreds (if not thousands) of melts to have their "final" transmission data. Jonathan basically measured only one melt, we should at least measure 10 or so to have more accurate data, but that's beyond practical for us.

[JMC]

I actually used the old Sydor data to start with, and it was a worse match t my measurements than the actual Hoya datasheet. As for batch numbers I have those on the filter packaging, but from looking at them I suspect they are batch numbers from the supplier database rather than actual 'melt numbers'. Batch to batch variability concerns me a lot less for Hoya and Schott than it does for some of 'no name' filters.

[ulf]

Batch to batch variability concerns me a lot less for Hoya and Schott than it does for some of 'no name' filters.

Normally I would agree with that, especially for the published data from them, but it could be that there are "acceptable" variations in the uncharted ranges, that for typical usage isn't important.

[Cadmium]

Melts: You can get the melt data for the glass. Certainly from Schott, I think from Hoya also.

The manufacture of the filter often has that melt data available, the variances are minor and not enough to be concerned with, especially for our concerns, but it can be requested.

Personally, I think you are over thinking this with that direction of thought, but nothing stopping you from asking for the melt data.

 

Schott vs Hoya U glass.

Hoya U glass (U-360 and U-340) transmits UV stronger and transmits Red/IR (700nm range) less than Schott U glass (UG1 and UG11) equivalents.

That is true, but it only really applies when using those alone without any stacked suppression.

In a stack, the red/IR end is controlled by the BG glass (S8612), it is what determines the suppression OD.

There is no need to concern yourself with the transmission of the red/IR end of the U glass when stacked, only with the transmission of the red/IR end of the BG glass. So toss that whole thinking aside.

The transmission of the UV end of the U glass is important in a stack, but the % is limited to the BG curve.

So for example, UG11 and U-340 perform about the same when stacked, even using the deepest UV transmission BG glass (S8612),

so for the UV range those two stacks will perform the same, even though U-340 has a slightly stronger transmission alone than UG11 does alone.

On the other hand, when stacked U-360 will have a slightly better performance than UG1, that is why I like U-360.

The reason I don't like U-340 is because when it is thinner it doesn't suppress some of the visual range quite as well as UG11,

but when it is 1.5mm thick or thicker (usually 2mm) U-340 is a lot less expensive than UG11, but I consider UG11 to be a better U glass, especially if stacking thin.

 

Examples:

 

Here is why I like U-360 more than UG1 (also note the reverse of the common thinking about the IR using Hoya in a stack):