pointing camera at the sun

[Red Squirrel]

I'd like to photograph the transition of Venus across the sun in June.
Is it safe to point a zoom lens and my 10d at the sun? Or will I damage the sensor?
Or is some sort of mylar filter necessary???

[CyberDyneSystems]

Lots of filters!

Yes you can burn out the C-mos.. and I understand there are other hazards as well (can't remember if it's shutter or aperture blades?)

[robertwgross]

This is similar to photographing a solar eclipse, and there are reference books on the subject. Basically, any time that you are shooting at a bright sun, you need a solar filter to block out 99% of the light. There are expensive solar filters, and then there are cheap ones. I used one once that was constructed out of a plastic mounting ring with aluminized mylar ("space blanket") stretched over it. Such a solar filter makes the sun so dark that you might have to search the sky to find the sun. It makes it sort of a dull gray color. So, getting a proper exposure gets thorny.

---Bob Gross---

[Andy_T]

I would also give some consideration to what the sunlight might do to your eyes, if focused through a set of lenses :roll:

Do a forum search on that issue!

Best regards,
Andy

[tony873004]

You can get a good solar filter for under $50 at any telescope store. It doesn't have to fit your camera, as long it's larger. A little bit of cardboard and duct-tape engineering should be able to modify it for you.
A mylar filter will do an excellent job at a reasonable cost. Your first impression of looking at the mylar filter will be that it looks like a cheap piece of s*** thats wrinkled and defective. Don't let this fool you. The wavy wrinkles won't show up in your picture.

You'll want a good zoom lens for this. At least 300mm, and I'd recommend getting a 2x adapter on top of this. Take lots of pictures, and at lots of different exposures. It will be interesting to see if Venus has a sharp edge, or a fuzzy edge due to its atmosphere. It hasn't transited the Sun since the 1800s, so there are no photographs of a Venus transit.

Also, practice in advance. It's very difficult to find the Sun with a filter on the lens. But when you do find it, study the shadows that your lens casts on the camera, or that different parts of your camera cast on other parts of your camera. Then on transit day, you can easily find the Sun by duplicating the shadows you saw on your practice run. Another method is to use a telescope or binoculars to project an image of the Sun on a white background. Here is my hurried attempt to catch a transit of Mercury in 1999. Having no solar filter at the time, I used my telescope to project the Sun onto a dinner plate. It is of course important that the object receiving the projected image is in shadow. Mercury is the tiny, almost invisible dot on the right edge of the Sun. Venus will be much larger. It will appear about as large as one of the large sunspots. I wish I had more time to set up this shot, and I wish I had practiced a few days before because I'm sure I could have done a much better job. I'm in California, so I won't get a chance to see this transit of Venus. I'm counting on you to get some good pics :D Good luck!
http://orbitsimulator.com/orbiter/Mvc-575x.jpg

Just for fun... Here my picture of the Moon transiting the Sun in January 1992. Because the Sun was setting, no filter was needed.
http://orbitsimulator.com/orbiter/1024_eclipse92.jpg

[robertwgross]

...
You'll want a good zoom lens for this. At least 300mm, and I'd recommend getting a 2x adapter on top of this.

Wow. You aren't going to fill up much of the frame with 300mm or 600mm, even with the x1.6 factor.

When I shot the total solar eclipse of '91, I was using 1500mm, and that was almost enough to fill the frame. If you were after something much smaller than the sun, like Venus, then you might consider something much longer.

For the eclipse, I was able to photograph solar flares in a hot pink color.

---Bob Gross---

[tony873004]

You're definately right. Bigger is better. But unless you're going to be using a telescope with a tracking drive, it also makes it much more difficult, as the Sun moves pretty fast and is much more difficult to locate at 1500mm. I recommended at least 300mm with the 2x adapter as this is the minimum to show anything. Just wanted to make sure he wasn't counting on an 18-55 zoom lens. :wink: Venus will show up in such a configuration. The annular eclipse photo above is 600mm (300 + 2x). It's a film shot, and the Sun obviously doesn't fill the frame, but the photo blows up well. My 300D with my 28-300 tamron at 300mm gives me a Sun about 350 pixels in diameter. Venus would be about 11 pixels at 300mm, or 700 / 22 for 600 mm.

Bottom line... Robert is right. So get the most mm you can for this event, and practice in advance on sunspots (like I wish I had done for my Mercury shot :oops: )

Robert, where did you see the '91 eclipse? I got rained out in Hawaii :( .

Just a crude approximation of what a 600mm picture would show (700 pixels Sun, 22 pixels, Venus):
http://orbitsimulator.com/orbiter/sunvenus.GIF

[robertwgross]

Robert, where did you see the '91 eclipse? I got rained out in Hawaii :( .


Ha! That was the trick.

I had been working a project on and off in Hawaii, so I knew about the eclipse several months in advance. Either you had to shoot from the Big Island, or Baja California, or a few other places beyond there. Obviously, I picked the Big Island. Besides, I can speak the language.

I realized that the path of totality was going to be almost straight across the Big Island. I studied a few books on the subject, including the weather books. I realized that for that time of year (July), there was a considerable chance of getting clouded out anywhere around the coastline where all of the resorts are. The only way to increase my luck would be to go above 6000 feet elevation, and that means the Saddle Road. Three months in advance, I got an air ticket from the Mainland to Honolulu, and then I barely managed to get an air ticket from there to Hilo. All of the resort lodging was sold out, and all of the rental cars were sold out. So, I flew out there with all my gear in one very large backpack. I needed to go up as high as possible on one of the volcanoes, and I needed to be self-sufficient for up to four days. I carried four gallons of water, food, camp gear, photo gear, including a 500mm lens and a 3x TC, and everything. The pack went 67 pounds. I took a taxi from the Hilo Airport up the Saddle Road. About 24-hours in advance I started, and by 12 hours in advance, I was set up ready to shoot from 12,000 feet on the north side of Mauna Loa. In the morning, the eclipse started, and I shot and shot and shot. A few minutes later, it was all over. I hiked on up to the summit and then hiked down the regular trail toward Volcano Village. I had been sleeping out in lava tubes for a couple of nights, so I found a B&B to stay at where some East Coast photographers were staying. They were all pissed off because they had paid big bucks to fly out and do that trip, and then they were clouded out. I explained that I paid practically zero, and I got the shot. The rest is history. But that was way back in my Konica days, and I have been married to Canon since 1997.

The best eclipse shot, I had it blown up to 16x20 and printed. I gave two of those to two of my important customers in Honolulu, and they were impressed.

---Bob Gross---

[cgratti]

I'd like to photograph the transition of Venus across the sun in June.
Is it safe to point a zoom lens and my 10d at the sun? Or will I damage the sensor?
Or is some sort of mylar filter necessary???

Id first want to protect your EYES, you can replace a sensor but they havent yet made a replacement for your eyes. Try going to some astronomical websites and searching for filters for the cameras and telescopes. It will only take a FRACTION of a second of you looking through your lens to burn your retnias to a crisp golden brown. Seriously, I would research this THOROUGHLY, and would NOT use any homemade filters, spend the money on your safety, or you may not be able to take pictures at all ever again.

[tony873004]

Thanks for sharing that. That's a cool story. Some good came out of my rain-out though. Always having loved astronomy, but knowing nothing about photography, I bought my first camera setup just for the eclipse. (Nikon 660, 75-300 zoom, 2x adapter). I probably would not have photography as a hobby today if it weren't for that event. And even though there were clouds and rain, it was totally cool watching the light level drop. It seemed like it took an hour for the light to drop from 100% to 90% and then 5 seconds for it to drop from 90% to 10% where it remained for totality. It was like somebody had their hand on a dimmer switch to the Sun. For the record, there were pleanty of rental cars on the island. When we made our reservations, they practically laughed at us when we asked if any rental cars were available, stating that they've been reserved for months, but when we landed, we took our chances and went to the rental desk. When she asked "what kind of a car do you want?" we quickly picked the convertable and a motorcycle.

[robertwgross]

Thanks for sharing that. ...
And even though there were clouds and rain, it was totally cool watching the light level drop. It seemed like it took an hour for the light to drop from 100% to 90% and then 5 seconds for it to drop from 90% to 10% where it remained for totality. It was like somebody had their hand on a dimmer switch to the Sun. For the record, there were pleanty of rental cars on the island. When we made our reservations, they practically laughed at us when we asked if any rental cars were available, stating that they've been reserved for months, but when we landed, we took our chances and went to the rental desk. When she asked "what kind of a car do you want?" we quickly picked the convertable and a motorcycle.

Yes, the time from first contact to second contact was something like 45 minutes or so. Then totality was only a few minutes. I was watching the totality approach, squinting sideways at the sun and then through the camera (with solar filter), and it stayed bright until the instant. Then saw something moving to the west, across the Pacific. I saw THE SHADOW sweeping across the ocean surface, and then it was upon me. That is when I got on the shutter button and started clicking away, maybe once per 15 seconds or so. Yes, the sun seemed to be moving, so I had to adjust the camera framing a tiny bit.

Some speculators had booked up the rental cars and blocks of hotel rooms well in advance. The state government and civil defense had things set up to handle 60,000 tourists on top of the normal tourist load. Then the inflated prices scared away some tourist agents, and the whole house of cards collapsed. They later estimated that there were fewer than 30,000 above normal, so some lodging and some rental cars went untouched.

Find me another photographer (in their right mind) who will carry almost 50% of their body weight in a pack, up a tall mountain, just to shoot a solar eclipse!

---Bob Gross---

[Volatile]

There will be some good comet opportunities in the next month or so.