Author Topic: Dangerous sun (in Dual-ISO)  (Read 689 times)

adrjork

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Dangerous sun (in Dual-ISO)
« on: April 16, 2018, 08:29:17 AM »
Hi guys,
perhaps this is not really a specific ML-forum-question... but you are Canon experts, and I'm worried:
Yesterday I shooted a very nice sunset (actually the sun was still high, let say late afternoon) and I wanted the sun in frame. Obviously zebra clipped on the little sun disc even with the ND filter and ISO 100, but anyway I decided to try Dual-ISO (100/800). After about 60 minus of shooting, I remembered that Canon manual says "no direct sun in frame"... and in many websites people say that direct sun light melts the sensor...
I'm stupid, I know. Now I'm worried I have damaged the sensor.
My question: with dead pixel method (THIS) is possible to understand if sensor is damaged? Or the damage could "behave" in other ways? Is it better to go to Canon service for a check?

This is my set during the session:
5D3, time 1/33, Dual-ISO 100/800 (zebra on sun even at 100), Tamron 24-70 (at 70), f/22 (2.8 only to focus) Hoya UV filter or Hoya ND filter (alternately), about 60' with liveview.

Thanks everyone in advance.

ArcziPL

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Re: Dangerous sun (in Dual-ISO)
« Reply #1 on: April 16, 2018, 09:00:46 AM »
Do you see any artifacts on your photos at the place where the sun was or are you just worried that something could have potentially happened?

If you see no issues, then all is fine. Stop worrying and make photos.
70D.112 | 700D.115 | M.202 | 450D.110

50mm1200s

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Re: Dangerous sun (in Dual-ISO)
« Reply #2 on: April 16, 2018, 01:44:29 PM »
If you're using UV and ND filter it's fine, I think. The sensor will only be exposed for miliseconds in photomode. You should worry only if you're recording videos and without UV filter...

ps: try HDRMerge and Rawtherapee "HDR Tonemapping"... you'll get better results.

ArcziPL

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Re: Dangerous sun (in Dual-ISO)
« Reply #3 on: April 16, 2018, 02:45:00 PM »
But he used live view for a longer time with opened aperture at f/2.8 -> this is the very critical moment. Exposure time when taking photo with f/22 you can completely ignore. I also don't believe that UV filter has any significant influence. ISO setting also not. ND yes, but it depends on the filter density.

Anyway, as said, if photos are normal, don't worry.
70D.112 | 700D.115 | M.202 | 450D.110

adrjork

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Re: Dangerous sun (in Dual-ISO)
« Reply #4 on: April 17, 2018, 02:59:13 AM »
Thanks a lot for your kind replies.
ArcziPL says right: I didn't take photos but videos, and liveview was active all the time. f/2.8 was used only for manual focusing, but yes, in those moments was zebra party... And I used Dual-ISO, that means that during shooting the sensor received both 100-ISO frames (with zebra on the sun only) AND also 800-ISO frames (zebra in the sky with diamonds...)
Do you see any artifacts on your photos at the place where the sun was or are you just worried that something could have potentially happened?
Well, I'm worried about the potential damage, yes, and up to now I didn't notice something strange in the footage, but today I was grading a frame in ACR and I noticed that with highlights slider all down, a magenta little lined disc appears internally the sun.
What does it mean? A simple fringe artifact, or a damage of a portion of the sensor?

50mm1200s

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Re: Dangerous sun (in Dual-ISO)
« Reply #5 on: April 17, 2018, 04:02:08 AM »
with highlights slider all down, a magenta little lined disc appears internally the sun.
What does it mean? A simple fringe artifact, or a damage of a portion of the sensor?

Probably the highlight reconstruction algorithm in ACR, don't worry. You can also try on rawtherapee, without reconstruction, so you can make sure about that.
tl;dr: if other photos are ok, don't worry.

mothaibaphoto

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Re: Dangerous sun (in Dual-ISO)
« Reply #6 on: April 17, 2018, 06:06:07 AM »
I've shot a lot of timelapses with sun in the frame, and never worried about sun itself.
Saltwater, waves, sand, rocks, wind tilting tripod... and so on - this is the real pain.
But i use wide lenses and polariser.
As far as I understand, the longer your lens, the more dangerous the sun. And at F22 you can damage not the sensor, but the aperture blades:
https://petapixel.com/2017/09/01/photos-cameras-lenses-got-destroyed-solar-eclipse/

adrjork

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Re: Dangerous sun (in Dual-ISO)
« Reply #7 on: April 18, 2018, 04:44:53 PM »
Thanks for your replies.
@50mm1200s: luckily I didn't find that artifact in the other shots, so I agree it was an artifact.
@mothaibaphoto: I checked the blades and seem fine (no oil, no melted parts).
Well, it seems it's all fine (hopefully).

SpcCb

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Re: Dangerous sun (in Dual-ISO)
« Reply #8 on: April 19, 2018, 10:37:40 PM »
It's important to say again : Never shoot the Sun directly.
Even with UV, IR, ND, polarizing, welding or something filters. None of them can block extremely strong and invisible part of the light spectrum from the Sun.
Even if the mirror is down : lens or/and body parts can get very hot, can brick or melt.
Even if  the focal is short, it depends of the diameter of the lens. (should be <5mm without diffraction part [a hole in fact] to not be 'more dangerous' than your eyes).
And the most important : A fraction of second of inattention and you can get severe and permanent damage in your eyes if you cross the light beam.

Every years I see medical reports of hundred injured persons.
Note that 2/5 of the cases are people who suffered of chronic headaches but don't remember that they look at the Sun in a camera. It's hard to discover that you will have chronic headaches for the rest of your life.. Think about that. And think it could be more dramatic.

Don't play to this game with your gear, and with your eyes !

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If you want to take images of the Sun, contact a Astronomy Club around in your place. They're usually very open to visitors and you could see what kind of special filters they use (to your eyes, absolutely no light looks pass through) to make it safe.

mothaibaphoto

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Re: Dangerous sun (in Dual-ISO)
« Reply #9 on: April 20, 2018, 06:44:06 AM »
...lens or/and body parts can get very hot, can brick or melt.
In the case of nuclear explosion:
To prevent the severe and permanent damage to the state boots by the melting iron,
the soldier must hold his rifle in outstretched arms.
(USSR army regulations)