IR filter ... EPR (Ektachrome Professional Slide E6)

[photoni]

My New Sony A7 fs with Meritar 50 mm @ f11

 

It's a test I did after @Picareto post
Floppy disk filter

to see if there are alternatives to the classic infrared filter

 

I used some slide developed in E6 , not exposed.

 

A friend advised me better to put 135 double film, or use a flat film that is thicker.

 

with classic Hoya R72

 

 

 

with EPR 4x5 inch film

 

-

 

 

 

 

and with one

EPR 135 24x36 Leica format

 

and ... EPR 135 double black film

 

 

-

 

[Picareto]

Looks very good to me.....

 

[photoni]

8 hours ago, Picareto said:

Looks very good to me.....

 

 

yes the flat film is incredible similar to an IR filter, but I have no idea of the real transmission...

better a Hoya R72 ø52 mm filter on amazon costs only 40€.

I kept some black 4x5" films because they are recommended for watching eclipses;

then some sites recommend them for photographing the sun,

the thing that struck me is that it makes the foliage white.

[lonesome_dave]

3 hours ago, photoni said:

I kept some black 4x5" films because they are recommended for watching eclipses;

then some sites recommend them for photographing the sun,

 

I think for safety it's worth clarifying something here.

Someone please correct me if I'm wrong but I recall that only B&W negatives (exposed & processed to black) are sort of OK for watching eclipses and that unexposed color-reversal slides (processed to black) let through too much IR for safe viewing (as seen above). I'm sure Toni was referring to B&W films and not the IR-passing slide film blanks used at the top of this thread but wanted to make it clear for anyone that might hit this thread with a search. Also, eclipse glasses are inexpensive and easy to find.

[photoni]

@lonesome_dave Thanks for the clarification, I said something stupid, your reasoning is logical and fair, it lets too many IRs through.
I wonder if there is anything in our bag that can be useful a ND ... Neutral Density ?

I have several BW negatives but it seems to me that the density of the "tail" exposed to light and developed in the standard way is very low.
I will try to leave flat BW film immersed in strong developer, in the sun, for half a day.
Thank you

[lonesome_dave]

Toni, I think you're right that even the B&W dark negs are not really eye-safe for solar viewing. I remember as a kid we used exposed film tails to view a partial eclipse and my old eyes are still good. However the thin base films such as High Speed IR appears less dense than what I remember using and would not want to try it.

The naked-eye eclipse viewers I use now are from Rainbow Symphony and Thousand Oaks Optical. I also have some thicker ones that are for putting on binoculars and they work great. They all appear to use various densities of Mylar. I always gut-check them for IR passage with my deepest electronic IR viewer but it only goes out to about 1500nm so not a perfect test. Probably a good idea to not spend too long staring through them.