Weird Patterns of Dots (Shooting into Sun)??

[Kevin Winzeler]

Has anyone seen this behavior before when shooting into the sun? (patterns of multiple red dots all over the frame).
I thought this was lens dependent at first using my Leica R set, but then threw on a Canon 16-35mm f/4 and had the same issue. I've never seen this before. Any ideas?

 

[Mike P.]

This is a commonly known artifact of CMOS sensors that happens when you point into a strong light source (like the sun) and close the iris all the way down. Open your f-stop/t-top (~f11) and use ND/Shutter to get exposure down to where you want it.

Don't worry, you're not the first or the last person to ask about this on RU (or any other camera forums).

 

[Daniel Kelly Brown]

I have had this problem on both MX and Dragon at high apertures, did not see any real improvement with Dragon with LLH or STH.

 

[Adrian Weinbrecht]

I have had this problem on both MX and Dragon at high apertures, did not see any real improvement with Dragon with LLH or STH.

That's interesting Daniel, we've only had this with the LLO when shooting into the Sun we always use the STH. Kevin was this a Dragon with the LLO or something else.

 

[Mike P.]

Haha, did you guys read my response or no? It might be more predominant with the LLO merely because you're having to stop down an additional 1.3stops, whereas with the STH you're open up by that 1.3stops. While it *HAS* to do with the OLPF, it's not Dragon/RED specific (it happens with all CMOS sensors that use an OLPF to varying degrees, including Alexa and even phones, and is a result of the back of a small iris catching reflections off the OLPF).

 

[Phil Holland]

I have had this problem on both MX and Dragon at high apertures, did not see any real improvement with Dragon with LLH or STH.

Haha, did you guys read my response or no? It might be more predominant with the LLO merely because you're having to stop down an additional 1.3stops, whereas with the STH you're open up by that 1.3stops. It has nothing to do with the OLPF or sensor per se (insofar as it happens with all CMOS sensors, including Alexa and iPhone, and is a result of a small iris... someone will post the iPhone pic shortly, I'm sure).

Actually it has everything to do with a specific layer and design difference between the Low Light Optimized OLPF and the Skin Tone - Highlight OLPF:

 

[Mike P.]

Actually it has everything to do with a specific layer and design difference between the Low Light Optimized OLPF and the Skin Tone - Highlight OLPF:

That the latest OLPFs handle it better is news to me! Thanks Dr.Phil!

That said, I thought it was a carry over from CMOS and more or less inherent to CMOS cameras that use an OLPF... While the updated OLPF handles it much better, I'd be curious if its reproducible in certain conditions. Again, it's the small iris reflecting off the sensor/OLPF and being visible on the back of the iris, right? Not sure if it could be eliminated entirely without removing the OLPF.

Also, in any case, if the OP wants to reduce the artefact on an old OLPF or the LLO, they can do so by opening the iris and using ND/Shutter instead.

 

[Kevin Winzeler]

Thanks guys. Yes, this is with the LLO OLPF. I'm interested in the sunburst at stopped down apertures, so opening up isn't an option for this shot. I'll try the STH OLPF as it looks like that is the answer.