Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

IR or Full spectrum

Check out this Vimeo channel:
https://vimeo.com/silverdoryproductions
They have quite a lot shot on the Kipper Tie IR OLPFs. Stumbled across them when I, like you, was searching for examples.
 
Thanks Nat,

This looks rad. The B/W look is pretty standard but I also like the false colour look you can get when you use different strength filters on the front of your lens. I guess combining a bit of grade magic to invert colours etc gives a pretty interesting look. It seemed this theme went cold before it even got hot.
 
Thanks Uros,

I also have both and just prepping for some experiments but figured there is a great resource here to make the most of.
I am needing to experiment with some different front of lens filters to tweak the false colour. B/W seems pretty standard for IR 720nm but its the 590-630 that is interesting.
Then there is the post workflow and even white balance to consider...
 
yeah im in the same boat as you, just choosing with OLPF setting inside the camera changes it so much already, havent decided even on that yet for the full spectrum one...
 
what do you set your OLPF setting in camera? also do you have any "looks" saved in red cine x you could share for both.
cheers,
Uros
 
Uros Zuraj said:
what do you set your OLPF setting in camera? also do you have any "looks" saved in red cine x you could share for both.
cheers,
Uros
Click to expand...

I use the IR OLPF calibration, gives me a better idea of what my image will look like in post. LLO works too, but I'd personally recommend sticking to IR (Just remember to switch back when you swap the OLPF! I already got burned once for that hahah)

I do have several "looks" saved in RED Cine. If I find some time this weekend I'll share them. Though most of the time I just prep an initial balance in Red Cine and then I grade them in FCPX or Resolved for video and Photoshop for Stills.

Few quick low-res samples:

IR
eg9MGCll.png


dV31Fn8l.jpg


Full Spectrum

i2aLYxUl.png


glYhnj8l.png
 
When I got my OLPFs I got one of the 720nm filters that Kippertie sells. I wasnt really that interested in IR but more interested in UV. Worked out that the Dragon sensor wasnt very sensitive to UV and pretty much couldnt get an exposure of UV only reflection. Forgot about the whole thing after that lesson.

Now my interest in IR has piqued again. I have been using the stills world for ideas but with stills they kind of have a much simpler processing option.
I am hoping to work out the coloured filters, RED, YELLOW and GREEN which I think were mostly used for B/W contrast but also cut wavelengths in IR photography too?
Kippertie sell coloured filters but I dont know the difference between these and specific nm values and how they affect an exposure on full spectrum with Red Dragon.

Can you dial in your looks in camera, dropping saturation and bumping contrast and get a pretty decent reference for b/w 720nm images? I cant remember if Dragon has abilty to 'auto white balance' either? I dont have my camera with my to test these things myself and as soon as I do ill be excited to try.
 
I cant remember how the OLPF presets end up in your camera? I dont know that anything happens automatically when I install my IR or Full Spectrum OLPF into the camera?
I know I have skintone and low light settings in my camera but I cant recall if this was something that just happened or if I had to load that in?

When I install an IR OLPF or whatever will that 'setting' be in the list of OLPFs in my menu?
 
Lee Kelly said:
I cant remember how the OLPF presets end up in your camera? I dont know that anything happens automatically when I install my IR or Full Spectrum OLPF into the camera?
I know I have skintone and low light settings in my camera but I cant recall if this was something that just happened or if I had to load that in?

When I install an IR OLPF or whatever will that 'setting' be in the list of OLPFs in my menu?
Click to expand...


Once you change your OLPF Go to Settings > Maintenance > OLPF and choose the IR option. Just make sure to change the setting back to your regular OLPF once you change your OLPF in camera.
 
Those of you who have shot IR, I'd like to ask on a sunny day (where you when shooting visible light may put on something like ND1.8), how much there actually is IR light to go by? So the question is that if you stay at ISO800, how fast your shutter speed has to be in order to get properly exposed IR images?

(EDIT: let's assume the aperture is at 2.0)
 
Is there any combination of OLPF and filters in front of the glass that provide 'normal' visible light with no low pass filtering?
I don't see any combinations that provide HVS full spectrum rather than full sensor spectrum without low pass filtering.
Do I have to manufacture such an option?

Also - seems the low pass filter strength should be different based on sensor site density / dimensions. But the Epic W uses same OLPF design as Dragon 6K and Weapon, right?

For the full spectrum pseudo color - that has no low pass - is it more than clear glass? Do you notice greater sharpness on Epic W 8K? Are you noticing lots of Moire?
 
DSMC1 cameras incorporate the quartz antialiasing filter and the colour separation filter into the interchangeable OLPF.

DSMC2 cameras have a fixed quartz AA filter and an interchangeable colour separation filter.

Hence, on DSMC1 one can increas sharpness (and add potential for aliasing) by using an interchangeable filter with no quartz antialiasing layers

On DSMC2 this is not possible without making a permanent modification that removes the AA filter. Very much not recommended.

Two further points:

Any glass used in the OLPF position requires carefully selected optical multi-coatings, and due to its location, extremely good tolerances for flatness, parallelism, surface finish etc.

Antialiasing is achieved with a two stage (3-layer) quartz birefringent filter. It relies on polarisation to function, and as such one can defeat one of the two axes of direction offset bynpolarising the incoming light with a linear polariser. The Red motion mount does this as a side effect of its design, and increased sharpness can be noted there on all systems.
 
And finally, your best options to achieve what you are requesting, not to be taken as recommended action:

DSMC1 : fit DSMC2 OLPF glass trimmed to fit DSMC1 frame. Backfocus will be wrong, but just within range of adjustment.

DSMC2 : remove (destructively) the AA glass behind the OLPF. Again backfocus will be badly messed up, but probably within adjustment travel.

To achieve correct backfocus in either scenario you would need a custom glass either of correct DSMC1 thickness, or a substitute high quality window custom made to bond in place of the AA filter.
 
John -
The technical insight without giving away the farm (so to speak) is very appreciated. Feel free to ignore comments / questions that wander across the line ;)

So (as in option 2) the AA glass is bonded to the back of all DSMC2 OLPF? It can be removed without impacting the 'color filter'?
The AA glass has some focusing effect - that is why back focus need to be adjusted? Or just based on the thickness of the glass and equivalent index of refraction? So optical quality flat could be used maybe. Assuming Kippertie is the manufacturer / assembler of all elements inn its OLPF line - could Kipppertie make such an OLPF - where the AA glass is replaced with an optical flat? I understand the manufacturing process may make that impossible without a new design / tooling process.

All Kippertie OLPF have the AA glass on the back of OLPF and it is similar in 'strength' to the RED OLPF? I wondered if the full spectrum with high and low cut frequency filters would provide non low pass filtered result but without any false color effects. Maybe too much loos with that approach.

BTW, it seems the 'strength' / cut off frequency of the anti-aliasing filter should be a factor of the sensor site geometry and density. So shouldn't dragon 6K have a different design than the helium 8K? Just in direct comparison of no OLPF DSLR 8k and Helium 8K I see a lot of 'blurring' in comparison.
Maybe weakening the OLPF partially with the polarization filter will correct that.

Any directional artifacts fromm the polarizer approach? Since the anti-alias filter seems to be summation of two 1D filters and only one of them is being bypassed - would there be directional sharpening effect? (such as horizontal edges versus vertical edges).
I know Canon redesigned their OLPF for 5DsR to get a partial cancellation between filter layers. (cf. www.adorama.com/alc/0015137/article/Canon-5Ds-vs-5DsR)

Thanks and you can respond via PM if you have a suggestion for custom Kippertie filter / cost or you don't want to broadcast.
Thanks,
Mike
 
You must log in or register to reply here.
Back
Top