I have the Canon 75-300 mm lens. I use Thousand Oaks black polymer solar filter film sandwiched between two glass filters screwed onto the front of the lens. To get an idea of image scale, here's a recent image I took, somewhat cropped. My camera has a crop sensor. At 300 mm, the disk of the Sun is small, but large enough to discern some detail.
The Sun - March 4, 2024To choose the right exposure, you can try putting the camera in Program mode and choose Center-Weighted Average Metering or Spot Metering if your camera has that option. Alternatively, you can use Aperture Value (AV) mode and choose a medium aperture such as f/10. In my experience, the narrower the f-stop (f/18, f/22, etc.) the slower the shutter speed will be and the more likely that you will see camera shakes and any sensor dust in your frames, even after cleaning the sensor. I most often use ISO 200 for high quality.
Aiming the camera is quite easy. An easy way I find is to turn your back to the Sun and adjust your aim while looking down the barrel. Just don't look at the Sun's reflection in the lens. When the barrel is completely in shadow, you can focus using autofocus in Live View. Focus on the limb of the Sun and when focused, switch to manual focus and your focus should be maintained for the duration of the eclipse. TIP: Wear a baseball cap to avoid accidentally looking at the Sun when behind the camera.
For my larger telephoto, to aim I use a cardboard shield that I made with a rectangular window of Thousand Oaks Black Polymer solar filter film. It allows me to safely aim the camera while facing in the direction of the Sun.
I have never seen a total solar eclipse yet, so I have no advice to give on totality. But I have successfully photographed the sunrise solar eclipse of June 10, 2021. I use a normal fixed camera mount. No tracking, but of course without tracking, each exposure requires adjustment.
Solar Eclipse - June 10, 2021SAFETY TIP: Don't use any filter that isn't designed for astronomy. Also, there are some solar filters out there that are designed for photographic use only. You want to use one that is safe for BOTH visual and photographic use in case you want to look through the viewfinder. You don't ever have to look through the viewfinder, but looking through it using a properly made solar filter screwed on the front of the lens is no different than looking through a properly solar filtered telescope in principle. You can buy ready-made solar filters for your camera filter thread size. I prefer Thousand Oaks solar filter film.
Hope this helps.
