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  • 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 :)

Dragon w/New OLPF issue? (Addressed by Red)

I agree that this issue should be gone with the new OLPF, and I thought it was,
but since it only shows up when stopped down it can be easily overcome.
 
There's so much DR from this good beast that I shoot NDs almost always if the sun is shining... especially if I'm pointing toward it.
 
I would like to try with my motion mount, when I get the new OLPF...

Thank you very much

Fury
 
T22 is max on that lens so probably shot at T16 since I never fully close down a lens. IMHO shooting T16 on a Summicron-C shouldn't break the sensor.

Cloudy this morning. Will do full tests when home in sunny SoCal this weekend. Any suggestions on testing other than this?

Range of Aperture
Range of Focal Lengths
With and w/o Motion Mount
With and w/o ND

The matte box ND is no magic fix . . . when pointing into the sun you can get internal reflection from light bouncing around behind the filter and causing a reflection of the lens. Also, the exposure I shot is the exposure I wanted . . . just without the red dots from hell

I don't have enough experience, therefore comfort, with the MM to keep it mounted and switching that piece in field is not always possible. Also, I'm trying to understand what the know aberrations with the MM are to know what to look for and when to avoid using it

Stay tuned
 
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Hi ZEB,

While I wait for the new OLPF and we both await the sunlight, please step through the motion mount, with zero ND dialed in, for sure and at 22, on a 75 Schneider, if you have one. That is, assuming the non MM gets the measles. Stepping by 0.1 ND on the MM would be great. If you would like to compare the Dragon old OLPF, vs. new, with that lens set, etc., let me know, as I am in the OC and maybe useful. In the meantime, what happens shooting into the hexolux ligts, linked together, for example?

Thank you very much

Fury
 
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Nick Fury said:
Hi Josh,

While I wait for the new OLPF and we both await the sunlight, please step through the motion mount, with zero ND dialed in, for sure and at 22, on a 75 Schneider, if you have one. That is, assuming the non MM gets the measles. Stepping by 0.1 ND on the MM would be great. If you would like to compare the Dragon old OLPF, vs. new, with that lens set, etc., let me know, as I am in the OC and maybe useful. In the meantime, what happens shooting into the hexolux ligts, linked together, for example?

Thank you very much

Fury
Click to expand...

Will do - got the Crons 18 - 100mm for the test
 
sergio arguello said:
thats really Horrible!!! Is this being addresssed or something that we have to contend with for now on...well when we get upgraded.
Click to expand...

While I agree the example is horrible looking, I don't think it is anything to be overly concerned about, as Josh has hinted. Simply do one thing different and the problem goes away. It's not as if it is some baked in thing as long as you allow for it when shooting.
 
Zeb,

+) If you are able to reproduce this with a zoom - could you also compare the results to a prime (fewer pieces of glass / should be less prevalent) at T22.

+) Zoom at T22, T16, T8 would be interesting.

I don't think (guess) the flare is IR related, and the fixed optical circumference of the MM is >> then T22 of the Corn, therefore I would not expect any difference in the position size of the blobs of flare ... but I would expect the linear polarising side of the MM to curtail internal reflections (guess: from the rear elements) of the zoom lens - and reducing red blobs, and (guess: to a lesser extent) the blue blob.

I guess this is lens dependent, with the closer the rear glass element of the lens to the sensor, the more likely the blobs will focus on the focal plane of the sensor.

AJ
 
Elsie N said:
While I agree the example is horrible looking, I don't think it is anything to be overly concerned about, as Josh has hinted. Simply do one thing different and the problem goes away. It's not as if it is some baked in thing as long as you allow for it when shooting.
Click to expand...


while its good that there is a fix, I can still imagine situations where regardless of whether your using ND or not you may still want a F (or t) 16...? like with a shotty 1st AC or one man band kind of shooting maybe, so you want a larger focal plane? it will be interesting to see some more tests done, i think trying various lenses with different element numbers is a great idea...if anyone with dragon and new olpf has a ton of still lenses that works too i think?
 
I wouldn't rule out it being his specific camera until more tests are conducted, I am sure Phil would of seen it if it was still present during his tests, same with Reds engineers
 
Mick van Rossum said:
No it's not. Does not happen on an Alexa...
Click to expand...

Allow me to quote an old message from Jeff Kilgroe:

Jeff Kilgroe said:
This is "OLPF" flare as it's often called. It's an internal reflection from the OLPF/ Sensor Block. Easy to reproduce on most CMOS and digital systems with reflective sensor structures. RED One shows it (both MX and on the original M sensor), so does Alexa and others. The Alexa's low-con filter overlaying the sensor block/ OLPF seems to soften it somewhat, probably because it becomes the outward reflective surface more so than the OLPF or sensor. Just one more layer of glass...

I'm not trying to drag the Alexa into a beat-down with this one, just mentioned it. It's easy to duplicate this sort of reflection or flare with *ANY* reflective sensor camera. If you look into a camera and see a shiny sensor surface reflecting back at you, then you know it's possible for light to bounce back and forth inside there.
Click to expand...
 
Brian Merlen said:
I wouldn't rule out it being his specific camera until more tests are conducted, I am sure Phil would of seen it if it was still present during his tests, same with Reds engineers
Click to expand...

Yeah, it would be good if Phil could wade in on this.
 
Don't shoot at f16 into the sun with ANY CMOS camera. They all will show this problem. Not a hard rule to follow - it's as basic as "don't clip the whites" and "keep your subject in focus".
 
This is a shot Detlev Eller posted of a Dragon still. I believe it was Paul Ellingtons camera. So that sensor pattern is still there in multiple cameras, not just Zeb's...

1899433_10203269404686163_1893616582_o.jpg
 
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