Jump to content
UltravioletPhotography

Hello from Denmark


TheMark

Recommended Posts

Hi

 

I'm a hobby photographer that are planing on venturing into UV / IR photographing

 

my plan is to convert my Nikon D800 to an UV+IR only camera (as I mostly take handheld photos)

by removing the AA, ICF and CFA and install a "DB395/870" / "Hoya U-330" / "SCHOTT UG11" filter on the sensor (to block visible light)

and then use either at UV or IR block filter in front of the lense to either take UV or IR photos, like the "Hoya HA30" or "Hoya Y50"

the main issue is trying to use 2 filters, that I will just end up blocking to much light to be able to use it handheld

where dedicating til to only UV or IR would probably be the better option as then I only need one filter "X-Nite 330" for UV or "X-Nite 830" for IR

 

also do any of you know if there exist any alternative to MaxMax in EU, so I can avoid all the problems with import/export tax

 

Mark Petersen

Link to comment

Welcome to UVP. I expect some of our members can point out the company that does modification in UK. Probably similar exists in Germany as well.

 

Do keep us informed about the progress of modifying your camera. I plan on converting my old D800 when my ordered Z cameras arrive in the near future.

Link to comment

So far I never have found a company in the EU that does CFA removal. ACS (advancedcameraservices.co.uk) in the UK only does UV & IR conversions. I once asked them if they remove the CFA as well but they don't.

 

Herman

Link to comment

Hello Mark and welcome to UVP! I hope you find the site useful and friendly. :)

 

That is in interesting plan for camera conversion. But I must ask, are you sure you might not want to simply make a full spectrum conversion given that you would be using two filters anyway? By making a full spectrum conversion, you have some freedom to experiment with more wavelengths than you would if you confine yourself to a U-330 or UG11. And you leave open the possibility of using just one dedicated UV-pass filter rather than a stack.

 

I think I should point out that the Hoya HA30 does not block Infrared sufficiently to permit good UV photos. The amount of IR it passes beyond 700 nm will contaminate a UV photo. You might want to look for an S8612 blue-green IR blocking filter at Uviroptics on Ebay or elsewhere.

[Note: UltravioletPhotography.com has no monetary affiliation with any vendor.]

 

I have not heard from anyone about a European conversion shop which removes the CFA. In the US we have, so far, only MaxMax (all cameras) and Monochrome Imaging Services (Sony only).

Link to comment

Mark, Yeah, Andrea is right. You should get a standard full spectrum conversion.

That will give you maximum flexibility to experiment and learn.

I would not get a monochrome camera (removed CFA) conversion.

 

 

Also, the filters you listed above "to block visible light", all of those transmit some visible light, red, and some blue and green as well,

but as long as you are not installing those inside the camera on the sensor, then we don't need to talk about those filters right now.

Just get a standard full spectrum conversion, then we can talk details.

Link to comment

Hi Mark,

 

As mentioned above, ACS who do UV and IR conversions do not do monochrome conversions. I would also recommend a full spectrum conversion, and keeping the Bayer filter. I have a monochrome conversion from MaxMax, and don't get me wrong it is excellent, but I got it for a very specific job originally. With the Bayer filter retained you'll still be able to get great monochrome images in the UV anyway. While you will lose some sensitivity in the UV, being able to capture 'colour' UV images will outweigh that.

Link to comment
Jonathan, a side question for myself: Is your MaxMax Monochrome a full spectrum conversion, or does it have a BG38 filter installed in it to suppress IR like Bob's has?
Link to comment

Jonathan, a side question for myself: Is your MaxMax Monochrome a full spectrum conversion, or does it have a BG38 filter installed in it to suppress IR like Bob's has?

Full spectrum Steve, the only internal filter is WG280.

Link to comment

Yes, using the "DB395/870" will limit the use of the camera, especially for UV as I need a extra filter like "Baader U" or "U-340" to block IR and I will need to use live view (witch annoy me like hell, as the D800 live view it is really slow to use, compared to the D850)

for IR I can use "DB395/870" with "LP515" on the lens and still use the viewfinder

but the "DB395/870" need to be custom cut, and it will stille be at 2+ filter solution, just so I can take IR handheld

If I convert it to full spectrum, the plan is still to remove the Bayer Filter, as I'm not at fan of fake color, but love BW, and that way I can use it with "SP700" to take normal BW photos, and if I want super colors I can use multiple photos each with a different bandpass filter :-)

as for normal Color I can just use my D850

 

so at the moment I leaning at full spectrum with no CFA

 

https://www.facebook...k/photos_albums

post-216-0-63749000-1540474505.png

post-216-0-75764900-1540475986.png

Link to comment

The first three things you need to know about any filter is the type of glass, the graph/plot, and the thickness.

Does anyone see the thickness stated anywhere for the Midopt filter graphs? Does anyone see any data sheets for the Midopt filters?

Let's say it is 2mm, which would be the thinnest I would expect it to be, but it could possibly be less.

The BP324 is a U-340/UG11 similar equivalent, however, it has a much higher 700nm peak of about 25%, as apposed to about 5% (U-340) and 7% (UG11).

The 700nm 25% Red/IR transmission is close to the 30% typically shown for ZWB1 glass, which I usually don't see a thickness listed for either.

I remind you that knowing the thickness is important, thickness is essential for calculating stacks and anticipating suppression and OD.

Also, having actual glass data, from a data sheet is important, because without that hard data, you can't accurately calculate anything, you would have to extrapolate the plot line of a graph, and turn it into transmission data, by eye, and doing that from a linear plot will not give you the fine data you need to calculate suppression and OD.

You need data to enter into a program to calculate from.

Data sheets are very important.

It is possible that those filters are made from Chinese glass (hey, just saying). For sure the BP324 is not Schott or Hoya glass, I can see that from the graph.

You might ask them what the thickness is for their graphs, and if they can provide data sheets.

Here are the Schott data sheets, to give you an idea. Take a look at UG11, for example.

https://www.schott.c...load/index.html

 

post-87-0-59844800-1540532083.jpg

Link to comment

called the local distributor here in Denmark

and the price differ greatly with size :-/

LP850-58mm $170

LP850-105mm $637

SP644-58mm $170

PB324-67mm $272

 

he looked up the thickness off one filter (1 mm), which one I do not know

Link to comment

I agree.

If MidOpt is guaranteeing a certain transmission level in a filter or filter set (for example, 85% in their StablEdge BP365 which is a 335-400 nm dual bandpass), then the actual thickness is somewhat irrelevant. Thickness will vary for each bandwidth in order to meet the stated transmission minimum of 85%.

 

But these MidOpt filters, unless further customized, are meant for industrial usage. I don't think I would spend what MidOpt is asking for their BP365 because you would need an additional IR-blocker stacked on it for our type of reflected UV photography. I would recommend instead buying one of the commercially manufactured UV-pass filters (BaaderU, SEU, KolariU or others) or creating your own filter stack with premounted Schott or Hoya filters.

 

MidOpt mentions that the substrate of the BP365 is Borofloat. It doesn't matter who poured the Borofloat or where it was poured as long as the final filter with all its coatings/layers/claddings/whatever meets the stated quality and transmission standards.

 

BTW, the MidOpt StableEdge technology is quite fascinating! It appears that this technology mitigates the concentric dichroic discolouration problem we've all experienced with dichroic filters. I am thinking about talking to MidOpt to find out about a custom IR-blocked version of that BP365. I would really like to experiment with it.

Link to comment

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...