Guy Mancuso
Administrator, Instructor
Jack shot something. So you want a shot with just the IR filter off the back only. Because i don't have any front filters right now for it
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JimCollum
Member
color IR.. both visible and IR light (preferable in the morning before the sun has come up)
Andy Biggs
Member
exactly! I am just wondering what the file will look like if I convert to B&W, and if it is worth asking somebody like Singh Ray to place a new filter in the IR filter's place.color IR.. both visible and IR light (preferable in the morning before the sun has come up)
I don't think you'll need it, seriously. One thing I noticed when I shot with the IR cut filter removed is that the glass obviously affects the light-path and point of focus. However, when removed, the focus moves CLOSER (hehe). Actually moves a little bit closer than the amount you need to compensate for the IR wave focus shift, so the two nearly cancel each other out. I ended up with focus about 15 cm closer than actual at a 3 m subject distance with normal focus --- pretty dang close for IR
Andy Biggs
Member
Good to hear, Jack. Good to hear.
Okay, crap. Embarassed to share this but here goes. A really ugly image but taken just because of the vegetation in it to see the IR behavior under open shade with mottled direct sun patches on the grass. FTR, the grass is very spring green, the flowers are red to magenta and the other vegetation varying shades of green and that's a redwood fence in the background. I processed in ACR, color temp 2000 and tint -140. I had over-exposed by about a stop, so this is pulled back -1, everything else normal. Lens was the 80 at f8, IR-cut filter removed, ISO 100.
The color, my B&W conversion and a crop of the B&W to show the in focus detail maintained.
The color, my B&W conversion and a crop of the B&W to show the in focus detail maintained.
Guy Mancuso
Administrator, Instructor
I maybe selling my ZD back to upgrade Jim. Will know after San Juan. Looks good
JimCollum
Member
what i'd really want is to be able to do this with the Aptus 75
(is leaf listening???)
Guy Mancuso
Administrator, Instructor
Probably not
Andy Biggs
Member
Jim-
I have done little other than take my system out of the box. I am trying to decide what my options are for lenses, as I just have the 80mm right now. More lenses are on their way.
I need to figure out my approach with IR on the ZD.
Should I:
1) just remove the IR cut filter
2) replace the IR cut filter with the filter that blocks visible light
3) just remove the IR cut filter and replace with standard glass
Are there any other options that I have missed?
I have done little other than take my system out of the box. I am trying to decide what my options are for lenses, as I just have the 80mm right now. More lenses are on their way.
I need to figure out my approach with IR on the ZD.
Should I:
1) just remove the IR cut filter
2) replace the IR cut filter with the filter that blocks visible light
3) just remove the IR cut filter and replace with standard glass
Are there any other options that I have missed?
JimCollum
Member
I replaced the IR cut filter with the Mamiya IR Photo filter (pretty much just optical glass). I then use the B&W 92 IR filter to remove most visible light, and get an IR image. From my Betterlight, i have a 77mm IR cut filter that i can place over the lens to get a 'normal' light image. This gives me the option of have either a normal image, a monochrome IR image, or a combination color /IR (luminosity layer= IR, color layer= normal light)
Andy Biggs
Member
Jim, are you referring to the YD401 filter that replaces the IR Cut Filter that Mamiya ships as standard on the ZD back? How much was it? I know Jack mentioned he got his from Keeble in PA. If it is standard optical glass, then all it is doing is protecting the sensor. I guess. If the filter isn't that expensive, I might see if I can get a 92 filter put in it. My goal is to block visible light and also preserve the ability for me to autofocus and compose normally.
I have also been looking into the IR false color 'look'. For those that are doing this, are they completely blocking out visible waves, or just some of them? I might not need to block anything if that is the case.
I have also been looking into the IR false color 'look'. For those that are doing this, are they completely blocking out visible waves, or just some of them? I might not need to block anything if that is the case.
Andy, yes that's the filter. It is just optical glass, but it does alter the optical formula and focus. With nothing over the sensor, IR is actually pretty significantly FRONT focused instead of the normal slight back focus --- IOW you cannot hit infinity without a filter over the sensor...
Jim likes the fact it's clear so he can do his two-shot capture of an IR and visible image for later blend. I have a Bettelight filter left over from my Betterlight days for visible too and may do the same thing, or may opt for having an 092 permanently installed in the YD401 frame and then generate monochrome or false color IR the way I normally do now with M8 files. Or I may just sell the ZD and forget all about doing IR now that I have the P45+ coming ----- need to do some testing
Jim likes the fact it's clear so he can do his two-shot capture of an IR and visible image for later blend. I have a Bettelight filter left over from my Betterlight days for visible too and may do the same thing, or may opt for having an 092 permanently installed in the YD401 frame and then generate monochrome or false color IR the way I normally do now with M8 files. Or I may just sell the ZD and forget all about doing IR now that I have the P45+ coming ----- need to do some testing
Andy Biggs
Member
OK. Sorry for being so dense. This makes sense now. I just wish Mamiya had a filter that actually cut out visible light. I just hope Singh Ray will do the custom work for me. They have always been great at stuff like this in the past, such as when I wanted a better polarizer for my 52mm drop in polarizer on my Canon long glass.Andy, yes that's the filter. It is just optical glass, but it does alter the optical formula and focus. With nothing over the sensor, IR is actually pretty significantly FRONT focused instead of the normal slight back focus --- IOW you cannot hit infinity without a filter over the sensor...
Jim likes the fact it's clear so he can do his two-shot capture of an IR and visible image for later blend. I have a Bettelight filter left over from my Betterlight days for visible too and may do the same thing, or may opt for having an 092 permanently installed in the YD401 frame and then generate monochrome or false color IR the way I normally do now with M8 files. Or I may just sell the ZD and forget all about doing IR now that I have the P45+ coming ----- need to do some testing
IR false color and/or dark skies is what I am after.