Shooting SOLAR ECLIPSE with Canon 300 mm f2.8 L IS lens....how do I add a solar lens

[Kzzzzz40]

Been using this lens for years and LOVE IT, with both the CANON gelatin UV and Polarizing drop in filters (52mm)...I thought it would be easy to purchase either a solar or ND (6-9 stops) or variable ND drop in lens and get ready for the Eclipse (April 8, 2024)....OH NOT THE CASE:

Canon: we don't make one...3rd party only

3rd party all sorts of ND/VND/Solar lens (52 mm) but all SCREW IN (ie like the front of the lens not the back where the drop in filter is (between bayonet and body)....BTW, canon says the face is a 5inch lens (equals 127mm by my math)

I"ve read numerous astronomy/lens users sites and they describe/show a picture of the drop in filter with a screw in lens...(at the same time down the discussion they alert all that it doesn't work, particularly with the V ND lens as its too thick....some wanted to shave it down to fit...OUCH)...

BTW< there are NO Threads on either gelatin/polarizing drop in filters...The cover does pop open on the gelatin/UV but the glass doesn't come out...

B&H wants to sell me a variable size (105-135 solar filter (for use w/ binoculars and telescopes too)...sounds like a patch night likely to produce high quality photos of the big day....

HELP!! Please include pictures of how you do it... This can't be such a problem as i'm told this is one of the top lens (300-600 mm FL) to use to shoot the eclips

[kvbarkley · Accepted solution]

You DO NOT want to use a drop in lens. That exposes the rest of the lens to damage from solar radiation. Instead, get a filter to attach to the front of the lens. I have had good luck with Thousand Oaks Optical.

[Kzzzzz40]

I've been able to verify that the concentrated light/heat generated from pointing the lens/camera body into the sun for ~2 hrs (total) can damage/burn the photosensor and shutter mechanism in the camera body. Placing a solar filter before the camera body would prevent damage from occurring to the camera body but I'll take it as granted (though not independently verified) that the unfiltered sun could damage the glass as well. This would support your position (and that of Thousand Oaks, etc) of placing a filter in front of the lens to protect everything "downstream". I remain concerned about the impact of the filter on the ultimate image quality particularly if it is not of optical quality with coatings and/or attached to the lens with "Velcro". Just seems to allow for imprecision which may effect the quality of the digital image...Thoughts??

BTW, the sun's radiation does not change during a solar eclipse, rather the "perception" of how bright the sun is when partially blocked by the moon which leads the normal unprotected human eye vulnerable to damage as one could "stare at the sun" longer than normal....

[kvbarkley]

Mine fits over my 150-600 and has three screws I can use to snug against the outside of the lens.

[Kzzzzz40]

Your "Thousand Oaks Optical" filter or a different one...The TOO filter on the website is too small for my lens (300 mm fixed f2.8 w/ ~110 mm inner threaded diameter to the lens (Canon erroneously said it was 5" glass, they weren't even close)...I need to verify the thread (coarser than any filter thread I've ever seen) and the specific diameter. I am measuring the outer diameter at 117mm....The TOO "FULL APERTURE (SOLARLITE POLYMER)" filter should work, but as I mentioned in above thread, what does it do to the optics and quality of the final digital image....Of course I'm between two sizes (112.7-117.5 or 117.5-119.1)....

[ebiggs1]

You can get shade 14  welders glass filter. But as stated above it must go on the front of the lens and remember to not look at the Sun yourself. A common habit motion when you use a camera to look at what you are shooting.

[Kzzzzz40]

Have read about this off label use, but my concerns remain around what the quality of the glass is (varying thickness/opacity/lack of lens coatings etc....

[ccanada]

@Kzzzzz40 where you able to sort out a solution based upon the feedback here in the community?

[Kzzzzz40]

I thank the quick replies, but I remain concerned about several factors that haven't been fully answered so far, including by Canon Technical Support....I'll keep trying!! Fortunately, I still have a month to acquire.

thanks

[kvbarkley]

You get what you pay for.

Here is what I got with my solar filter:

Note that you can see sunspots.

In any case, the solar filter is only until totality, at that point you can take the filter off and capture the corona with the full quality of your rig.

No one needs to protect the camera body, only the internals of the lens and camera.

I suggest trying a telescope manufacturer to get the best quality.