New MidOpt BP850 filter - what is it used for? (Corrected designation)

[Doug A]

Purchased super inexpensively. Thought I was buying an 850 IR filter, similar to the small 40.5 for the Pentax 645 DFA 25 mm lens. Nope, instead of dark black, this filter is super dark metalic purple. So what is this used for on a full spectrum camera?

Thanks,

Doug A

[dabateman]

Is that name correct? 

Should it be DB850?

I can't find a Dp850 filter.

[Andy Perrin]

The DB850 is not new though. Lots of us have those already. Also it passes visible light so it’s not like Doug described. 

[Doug A]

@dabateman and @Andy Perrin  no the name is wrong, sorry. It should be BP850. Think autocorrect changed it. It changed MidOpt to Minolta, which I caught. Didn't  realize it changed the filter letters at the same time. I'll fix the original question. The filter surface is so pretty.

Thanks,

Doug A

[Andy Perrin]

Doug and everyone. There are two different filters. 
 

https://midopt.com/filters/bp850/

https://midopt.com/filters/db850/

 

 

[dabateman]

There are many 850 type filters. I have a Bn850, its a narrow band filter. It only lets in light in the 800nms. So you can image with a lp950, bn850 and a filter that only lets in the 700s for IR tricolor. 

Some moss and trees had some interesting patterns with it. Also as just an IR filter, its quite nice. 

 

The bp850 is an IR filter with lots of 900s added as well. The Midopt filters aren't just long pass filters, but have coatings and interference coatings.  So it won't be just black. Hold it up to a light and see if you can see through it.  If you can than there might be a problem with it. 

[Doug A]

1 hour ago, dabateman said:

There are many 850 type filters. I have a Bn850, its a narrow band filter. It only lets in light in the 800nms. So you can image with a lp950, bn850 and a filter that only lets in the 700s for IR tricolor. 

Some moss and trees had some interesting patterns with it. Also as just an IR filter, its quite nice. 

 

The bp850 is an IR filter with lots of 900s added as well. The Midopt filters aren't just long pass filters, but have coatings and interference coatings.  So it won't be just black. Hold it up to a light and see if you can see through it.  If you can than there might be a problem with it. 

Thanks for the explanation. Can't see a thing thru it. The surface changes from mirror blue to purple, depending on the angle. I'll give it a try when the weather cooperates. 

 

Thanks,

Doug A