1. Reminder: Please user our affiliate links to get to your favorite stores for holiday shopping!

Parcial Solar Eclipse in PT (europe?) the 20th of April 2015

Discussion in 'Astrophotography' started by pmpup4p3, Mar 17, 2015.

  1. pmpup4p3

    pmpup4p3 Mu-43 Regular

    57
    Jun 23, 2014
    Hello everyone,
    I'm considering taking some photos of the upcoming solar eclipse.
    I have a GX7 and am thinking of using a Pana 100-300 to take the picture...
    I've read some threads on it, but couldn't quite make out the details, so here are some questions if someone can help:
    Do I absolutely need a special filter, not ND? If so, what kind? Can someone give me a link in amazon or somewhere else?
    Why the special filter? Better colors/picture or to prevent damage to the camera?
    Thanks.
    Pedro.
     
  2. MikeB

    MikeB Mu-43 Regular

    125
    Jun 10, 2010
    Atlanta, GA
    Short answer: either use a dedicated solar filter, or you need to stack over a dozen ND filters together. You need this to prevent melting of the camera internals due to heating from concentrated sunlight.

    Longer answer: Technically, a solar filter is just an ND filter that blocks at least 12 stops of light, so some people get by with very strong ND filters. But ND filters may not do a good job of rejecting infrared (heat), so you are better off with a real solar filter. Since we have live-view and not a dslr mirror in front of the sensor, our sensor is always exposed to the full heat of the sun, so you can't count on short exposure time to protect your camera internals.

    There's lots of different types of solar filters, some are made of coated glass, some are mylar film, some are a type of polymer plastic. Each has it's advantages and disadvantages. Ruggedness is important, you don't want a scratch or puncture to start letting in unfiltered sunlight. Each filter type will also provide a bit of a color tint, some filters produce a more orange or yellow image, some are more whitish or even blue (easily fixed in post-processing, you really aren't getting much color information off the sun anyways). I like the filter I have, think it uses a mylar film from Baader Planetarium, but it's a few years old and newer materials seem to be on the market now.
     
    • Appreciate Appreciate x 1
  3. m4c

    m4c Mu-43 Regular

    82
    May 15, 2014
    Czech Republic
    Ondrej
    Not that I´m going to use that, but doesn´t the glass used in welding helmets do the trick ( of course, that you need to get rid of the green tilt in post). Sorry if it is really stupid question :)
     
  4. Petrochemist

    Petrochemist Mu-43 Top Veteran

    651
    Mar 21, 2013
    N Essex, UK
    Mike
    Yes, welding glass works well, unlike standard ND filters it always reduces UV & IR as well as visible. Shade 13 or above is best.
    As MikeB points out stacking ND filters may have minimal effect on heat build up, the dyes used in many ND filters loose their effect by 850nm.
    I'll either be using welding glass or projecting an image onto the ground - if the skies are clear enough to see anything.
     
  5. MadMarco

    MadMarco Mu-43 Veteran

    298
    Oct 30, 2014
    Guildford, England
    • Appreciate Appreciate x 1
  6. Briar

    Briar Mu-43 Regular

    117
    Jun 13, 2010
    Bonnie Scotland
    Can I just check, you mean 20th March, not April for the solar eclipse. Not much time to order anything online for this event.
     
  7. pmpup4p3

    pmpup4p3 Mu-43 Regular

    57
    Jun 23, 2014
    Yes, my mistake, March, in 3 days... so, no, not much time, probably will have to wait for the next eclipse :(
     
  8. EdH

    EdH Mu-43 Top Veteran

    629
    Jul 14, 2014
    Devon, UK
    Ed
    16251275323_a701421d16_c. Eclipse by Ed Herridge, on Flickr

    I managed to get this shot of it (posted elsewhere with no special equipment, but it was a misty morning. The mist acted like a big ND filter I suppose.
     
    • Like Like x 3
    • Winner Winner x 1
  9. Delb0y

    Delb0y Mu-43 Regular

    77
    Aug 31, 2014
    This was mine from a rather cloudy Gloucester. Taken on the G3 with a ND8 filter on the front. It's a cheap filter and I think it's what's created much of the colour! Didn't know I could melt the camera innards by pointing at the sun. Luckily it seems to have survived!

    16251476603_096aa8d683_b.
     
    • Like Like x 3
  10. pmpup4p3

    pmpup4p3 Mu-43 Regular

    57
    Jun 23, 2014
    Here in PT, there were no clouds, and since I still have no filter, I'll have to wait for the next eclipse...
    Thanks for the pics
     
  11. Petrochemist

    Petrochemist Mu-43 Top Veteran

    651
    Mar 21, 2013
    N Essex, UK
    Mike
    Well without a filter you could have made a pinhole viewer or projected it via a lens onto something.
    I used a lens to project the transit of Mercury a few years back & it worked well.
    Too late for this one I'm afraid.