Focusing on the Sun

[tim eqs]

Hi Everyone

I took the attached photo of the Sun yesterday using an ND 10,000 filter and the following exposure settings:

Shutter Speed 1/2000

F 8.00

ISO 400

I have seen a photo of the Sun on Flickr taken with an ND 10,000 filter and exposure settings which result in approximately the same exposure as my photo. The photo on Flickr has sunspots but mine doesn't. From looking at NASA's SOHO website, I know that the Sun does currently have a few small sunspots on it so I am wondering why they did not appear on my photo.

I think I might possibly know the answer to this question but I don't know for sure. I used manual focus to take my photo. I think that there might be something about the combination of settings and filter that I used which meant that when the sun was out of focus, the resulting blurry glare around the sun was uniformly very bright up to a particular radius, at which point, the blurry glare completely stopped outside that radius. This would have mislead me to believe that the Sun was sharply in focus when it wasn't and the small sunspots would have therefore been blurred out of existence. Does this sound like a plausible explanation?

My camera's zoom lens seems to focus beyond infinity which means I unfortunately can't rely on just turning the focus ring as far as it will go. Does anyone know the best way of focusing on the Sun under these circumstances?

Thank you very much.

Kind regards

Tim

 

[Sir Canon]

Hi Everyone

I took the attached photo of the Sun yesterday using an ND 10,000 filter and the following exposure settings:

Shutter Speed 1/2000

F 8.00

ISO 400

I have seen a photo of the Sun on Flickr taken with an ND 10,000 filter and exposure settings which result in approximately the same exposure as my photo. The photo on Flickr has sunspots but mine doesn't. From looking at NASA's SOHO website, I know that the Sun does currently have a few small sunspots on it so I am wondering why they did not appear on my photo.

I think I might possibly know the answer to this question but I don't know for sure. I used manual focus to take my photo. I think that there might be something about the combination of settings and filter that I used which meant that when the sun was out of focus, the resulting blurry glare around the sun was uniformly very bright up to a particular radius, at which point, the blurry glare completely stopped outside that radius. This would have mislead me to believe that the Sun was sharply in focus when it wasn't and the small sunspots would have therefore been blurred out of existence. Does this sound like a plausible explanation?

My camera's zoom lens seems to focus beyond infinity which means I unfortunately can't rely on just turning the focus ring as far as it will go. Does anyone know the best way of focusing on the Sun under these circumstances?

Thank you very much.

Kind regards

Tim

few things. its around the solar minimum right now where there is the least amount of activity going on. and i suspect that you are still over exposed.

this is a very dangerous thing to do as the nd filter does not block invisible rays like uv and ir from making it to your sensor and/or eye

--
I tend to overdo things

 

[tim eqs]

this is a very dangerous thing to do as the nd filter does not block invisible rays like uv and ir from making it to your sensor and/or eye

Hi Sir Canon

Thank you very much for your reply.

Thank you also very much for your concern over the safety of my eyes and my camera. However, I can assure you that I did not look directly at the sun with my eyes and my camera has an EVF so it is not possible to be blinded by looking through the viewfinder.

I have actually seen plenty of photos and videos of the Sun on the Internet and on TV taken by professionals without any filters where no damage to the sensors seems to be done. Do you think they are risking damage to their equipment?

Thank you very much.

Kind regards

Tim

 

[rnclark]

Hi Everyone

I took the attached photo of the Sun yesterday using an ND 10,000 filter

Which ND filter (model and manufacturer)?

I have seen a photo of the Sun on Flickr taken with an ND 10,000 filter

I suggest you let people who took that image and those viewing it that this is very dangerous. See:

How to Photograph the Sun, Clarkvision.com

and exposure settings which result in approximately the same exposure as my photo. The photo on Flickr has sunspots but mine doesn't. From looking at NASA's SOHO website, I know that the Sun does currently have a few small sunspots on it so I am wondering why they did not appear on my photo.

It looks like your image is overexposed.

Roger

 

[Sir Canon]

this is a very dangerous thing to do as the nd filter does not block invisible rays like uv and ir from making it to your sensor and/or eye

Hi Sir Canon

Thank you very much for your reply.

Thank you also very much for your concern over the safety of my eyes and my camera. However, I can assure you that I did not look directly at the sun with my eyes and my camera has an EVF so it is not possible to be blinded by looking through the viewfinder.

I have actually seen plenty of photos and videos of the Sun on the Internet and on TV taken by professionals without any filters where no damage to the sensors seems to be done. Do you think they are risking damage to their equipment?

Thank you very much.

Kind regards

Tim

they were probably images with the sun close to the horizon. if that is the case then it its pretty safe to image and look at since it is through loads more atmosphere.

 

[tim eqs]

Sir Canon wrote:
they were probably images with the sun close to the horizon. if that is the case then it its pretty safe to image and look at since it is through loads more atmosphere.

What about the photo in the following link?

http://news.bbc.co.uk/1/hi/world/africa/7346133.stm

 

[Sir Canon]

Sir Canon wrote:
they were probably images with the sun close to the horizon. if that is the case then it its pretty safe to image and look at since it is through loads more atmosphere.

What about the photo in the following link?

http://news.bbc.co.uk/1/hi/world/africa/7346133.stm

its completely blown out there is no detail on or near the sun at all

 

[tim eqs]

What about the photo in the following link?

http://news.bbc.co.uk/1/hi/world/africa/7346133.stm

its completely blown out there is no detail on or near the sun at all

But is the BBC photographer risking damage to the sensor?

 

[rnclark]

What about the photo in the following link?

http://news.bbc.co.uk/1/hi/world/africa/7346133.stm

its completely blown out there is no detail on or near the sun at all

But is the BBC photographer risking damage to the sensor?

Yes. Having said that, if you look through this thread:

Solar Photography, including Eclipse Photography and Safety

Solar Photography, including Eclipse Photography and Safety

I finished my article on solar photography enough to release it. See: http://www.clarkvision.com/articles/photograph-the-sun/ Comments welcome. I still have work to do, but need to complete some other things first. Roger

www.dpreview.com

On page 3 you will see heating of he eye with different exposures, and camera heating will be similar. One paper cites a 22 degree C rise in temperature with a 7 mm aperture and 90 second exposure. For a wide angle lens, say 18 mm and f/4, that would be a 4.5 mm aperture and if the image was made quickly, heating would be minimal.

People have the sun in their eyes, but a bright sun will close your iris down to a couple of mm, reducing the danger from quick exposure and if far from the center of vision, the elliptical projection of the iris lets in less light.

But now look at your image: 300 mm f/4.8 lens (image at f/8). The camera keeps the aperture wide open except when exposing (that includes live view). So in live view, you have 300/8 = 37.5 mm, which is (37.5/7)^2 ~ 29 times more light. You have an ND filter, but it may transmit a lot of IR. IR energy from the sun is about half of total solar energy. Assuming 50% IR transmission, that could be heating of 22 degrees in 90 / (29 *0.5 *0.5) = 12 seconds. I bet you had your camera pointed at the sun for a lot longer than 12 seconds.

Bottom line, lens aperture is the key to collecting light, whether you want it or not, and that includes damaging UV and IR. And the danger increases as the aperture increases, as with the use of a telephoto lens.

Roger

 

[tim eqs]

Hi Roger

Thank you very much for your detailed replies.

I have tested my camera since yesterday's photography session with the Sun and it does not seem to be at all damaged. Do you think that damage to camera sensors by the Sun can be a gradual process? By this, I mean a process where by you don't notice the damage at first but if you keep exposing the sensor to the Sun, the exposed pixels gradually deteriorate over time?

Or is damage to sensor pixels a binary thing whereby if a pixel is at all damaged, it is totally dead?

Thank you very much.

Kind regards

Tim

 

[atigun]

Well known photographer Bjørn Rørslett set an IR converted camera body on fire while shooting the first Venus transit. The image he got just before the fire was spectacular though as he somehow manged to salvage the memory card. So yes, damage can happen.

I have on occasion pointed an unprotected long lens towards the sun nearer to the horizon using live view, but then all focusing etc. is done with the sun out of the frame, and the camera moved to catch the sun in the frame for only a fraction of a second. I would never want to do that with the sun high in the sky of course.

--
Atigun valley, a place north in Alaska

 

[a7sastro]

[No message]

 

[W5JCK]

Hi Everyone

I took the attached photo of the Sun yesterday using an ND 10,000 filter and the following exposure settings:

Shutter Speed 1/2000

F 8.00

ISO 400

I have seen a photo of the Sun on Flickr taken with an ND 10,000 filter and exposure settings which result in approximately the same exposure as my photo. The photo on Flickr has sunspots but mine doesn't. From looking at NASA's SOHO website, I know that the Sun does currently have a few small sunspots on it so I am wondering why they did not appear on my photo.

I think I might possibly know the answer to this question but I don't know for sure. I used manual focus to take my photo. I think that there might be something about the combination of settings and filter that I used which meant that when the sun was out of focus, the resulting blurry glare around the sun was uniformly very bright up to a particular radius, at which point, the blurry glare completely stopped outside that radius. This would have mislead me to believe that the Sun was sharply in focus when it wasn't and the small sunspots would have therefore been blurred out of existence. Does this sound like a plausible explanation?

My camera's zoom lens seems to focus beyond infinity which means I unfortunately can't rely on just turning the focus ring as far as it will go. Does anyone know the best way of focusing on the Sun under these circumstances?

Thank you very much.

Kind regards

Tim

Get a damn solar filter and stop trying to argue based on what you have seen on the internet. Want to buy the Brooklyn Bridge? I'm sure someone on the internet will gladly sell it to you! A day after you took your out of focus and quite useless image I took this one with a Thousand Oaks glass solar filter. Hey, you can actually see sunspots in mine, though the sunspots are rather small since the sun is not that active at the current time. So three things:

• Stop believing all the BS on the internet
• Get a good solar filter by a reputable company
• Learn to focus manually on the sun

Sun captured on 3 April 2017 with Sony a6000 and Canon 400mm f/5.6L lens and glass solar filter

--
Best Regards,
Jack
https://www.flickr.com/photos/jackswinden

 

[rnclark]

stop trying to argue based on what you have seen on the internet.

• Stop believing all the BS on the internet

Ironic. That is the problem--separating the BS and alternative facts from the accurate knowledge. And for the new person trying to get into the field that can be challenging. So for those new here, the best thing is to help educate, not berate.

• Get a good solar filter by a reputable company
• Learn to focus manually on the sun

On these two points, I agree.

Roger

 

[tim eqs]

Your rebuttals to good advice about equipment safety "what about this, this" isn't getting you far, there is a reason solar imaging excluding eclipses doesn't have a lot of imagers using ND filters......

W5JCK wrote:

Get a damn solar filter and stop trying to argue based on what you have seen on the internet. Want to buy the Brooklyn Bridge? I'm sure someone on the internet will gladly sell it to you! A day after you took your out of focus and quite useless image I took this one with a Thousand Oaks glass solar filter.

I believe that the best way to get to the truth about anything is to engage in a good debate about it with different points of view. Being rude to someone because you think they are going in the wrong direction is nothing but very destructive.

 

[tradesmith45]

Hi Everyone

I took the attached photo of the Sun yesterday using an ND 10,000 filter and the following exposure settings:

Shutter Speed 1/2000

F 8.00

ISO 400

I have seen a photo of the Sun on Flickr taken with an ND 10,000 filter and exposure settings which result in approximately the same exposure as my photo. The photo on Flickr has sunspots but mine doesn't. From looking at NASA's SOHO website, I know that the Sun does currently have a few small sunspots on it so I am wondering why they did not appear on my photo.

I think I might possibly know the answer to this question but I don't know for sure. I used manual focus to take my photo. I think that there might be something about the combination of settings and filter that I used which meant that when the sun was out of focus, the resulting blurry glare around the sun was uniformly very bright up to a particular radius, at which point, the blurry glare completely stopped outside that radius. This would have mislead me to believe that the Sun was sharply in focus when it wasn't and the small sunspots would have therefore been blurred out of existence. Does this sound like a plausible explanation?

My camera's zoom lens seems to focus beyond infinity which means I unfortunately can't rely on just turning the focus ring as far as it will go. Does anyone know the best way of focusing on the Sun under these circumstances?

Thank you very much.

Kind regards

Tim

Roger has given you good advice about filter needs for white light solar.

I have used the MZ75-300 for solar w/ a 1/1,000,000+ solar safe filter but with OMD bodies rather than Pen. There were sun spots yesterday so overexposure may have lost those details or you miss the focus.

Focusing on the sun w/ a long lens is pretty challenging - high ambient light, camera shake, any haze, etc. And 300mm gives a pretty small image. Awhile back I posted this and have used this hoodman like device now several times. It is by far the best focus aid I've found for solar. https://www.dpreview.com/forums/post/58968237

You will need to make a different arrangement of the small elastic cords to use this on the Pen. For best focusing with this, turn on IS, use mag live view starting at maybe 5x & increase magnification as you get close to nailing focus. When there are sun spots use them for focus. When there are none, I focus on the solar edge & watch for a crisp edge but if the air is very turbulent, there's haze or thin clouds, this is pretty tough. You can leave IS on even on the tripod but it will cause the sun image to drift around a bit. When you think you've nailed focus make a test image & view w/ magnification. Repeat as needed. Know that even w/ sun spots an unprocessed image will look very soft. You won't really be able to confirm you've nailed focus until after doing some post.

You'll get better at this with practice.

 

[a7sastro]

Reacting to contrary opinions and critique of your style of retort and labeling them as "rude" is often as well destructive, yes?

 

[Glack]

Hi Everyone

I took the attached photo of the Sun yesterday using an ND 10,000 filter and the following exposure settings:

Shutter Speed 1/2000

F 8.00

ISO 400

I have seen a photo of the Sun on Flickr taken with an ND 10,000 filter and exposure settings which result in approximately the same exposure as my photo. The photo on Flickr has sunspots but mine doesn't. From looking at NASA's SOHO website, I know that the Sun does currently have a few small sunspots on it so I am wondering why they did not appear on my photo.

I think I might possibly know the answer to this question but I don't know for sure. I used manual focus to take my photo. I think that there might be something about the combination of settings and filter that I used which meant that when the sun was out of focus, the resulting blurry glare around the sun was uniformly very bright up to a particular radius, at which point, the blurry glare completely stopped outside that radius. This would have mislead me to believe that the Sun was sharply in focus when it wasn't and the small sunspots would have therefore been blurred out of existence. Does this sound like a plausible explanation?

My camera's zoom lens seems to focus beyond infinity which means I unfortunately can't rely on just turning the focus ring as far as it will go. Does anyone know the best way of focusing on the Sun under these circumstances?

Thank you very much.

Kind regards

Tim

It seems that you overexposured the sun by about 3 stops.

Below I attach the shot taken with Baader AstroSolar filter ND 3.8 (1:6300), f/10, ISO 100, 1/4000 s.


Nikon D800 + MC MTO-11CA 1000 mm f/10 + Baader AstroSolar filter ND 3.8, ISO 100, 1/4000s.

 

[tim eqs]

Thank you very much indeed to Sir Canon, rnclark, atigun, tradesmith45 and Glack for your advice and help and for the politeness in any critique you gave me.

Reacting to contrary opinions and critique of your style of retort and labeling them as "rude" is often as well destructive, yes?

I don't mind polite critique so long as my opinions are not treated as a waste of time. I believe that all opinions are valid unless proven otherwise.

I notice that a7sastro seems to have retracted his original message on this thread because it now just says "No text".