Mars close to Earth right now

Discussion in 'Casual Photo Conversations' started by sjmurray, Aug 3, 2018.

  1. I might never get to take any, I need a clear sky like there was the other night when I caught a glimpse of Mars but only had cloud cover since

    I'll try anything with film but 800 is highest I've got so I'll give it a go if I get a chance
     
  2. You won't need ISO 800. Mars reflects the light from the sun. My photo was took at 1/60, f/8, ISO 200, but it's overexposed.
     
  3. Indeed. I guess the sunny f16 rule would be a good place to start. How close to 18% grey is Mars?
     
  4. Even though Mars is about as close as it ever gets to earth, any photos of the planet are not going to show much since there is a massive dust storm on the planet that is obscuring any detail.
     
  5. Ray House

    Ray House Ray House

    1/125th - f13 - 200 ISO, Nikon 70=300 @ 220mm. Don't know why 220mm, thought it at 300mm! Best I could do...Oh, and Nikon D90 Mars.jpg
     
  6. Men have been pointing telescopes at Mars since Galileo, and not seeing much. Even astronomers filled in details from their imagination, seeing canals and such. We didn't know much until the first Martian probes were launched, and the last 10 years or so has seen a phenomenal growth in knowledge. Just last week, scientists discovered a large, underground lake of liquid water under one of the poles.

    The albedo (reflectance) of Mars is between 0.17 and 0.25, so "Sunny 16" would be appropriate.
     
  7. The sky was clear tonight, Mars was directly over my head at 11pm, half way through it's path from rising to setting

    I set the Canon IXUS 960 compact to various ISO speeds and took several shots resting the camera against the car

    With this first shot, just for fun, I clicked "Auto Levels", check it out

    Mars 2.jpg
     
  8. This is the same image without any post processing. There's camera movement. ISO 200 f5.8 - Shutter speed unknown, the exif data only has "Shutter Speed Value 0"

    Mars 3.jpg
     
    Moving On likes this.
  9. paul ron

    paul ron NYC

    DSLR seems to pixilate tiny mars so it looks like the nucleus of an atom.

    more power Scotty.
     
  10. The Sunny 16 rule applies to terrestrial scenes, and it needs to be adjusted for something like Mars, which is farther from the light source (the Sun) than the Earth. Mars receives a little less than half the sunlight as does Earth. In addition, the light from Mars needs to pass through our entire atmosphere, which scatters and absorbs light, further diminishing its brightness. For a photo of Mars, Sunny 16 may need to be modified to Sunny 9.5 or even Sunny 8.
     
    chulster likes this.
  11. Even at "Sunny 8," which is quite reasonable, the shutter speed at f/2.8, ISO 100 would be 1/800, not several seconds needed for star images and the milky way.
     
  12. Sandy Vongries

    Sandy Vongries Administrator Staff Member

    ?
     
  13. Vincent Peri

    Vincent Peri Metairie, LA

    Later in the same sentence, he says the shutter speed is 1/800 ("at f/2.8," which he put first in the sentence.)
     
  14. One should not underestimate how small Mars appears. Even when it is closest and biggest in apparent size it is about visually equivalent to a billiard ball 600 yards away. That's way too tiny for a DSLR and zoom lens to give detailed images. Remember, the best astronomers using the biggest earth based telescopes after a couple of centuries of research effort could not produce consistent maps of the place. We needed satellites and rovers to do that.
     
  15. What's interesting is that I'm getting different sized Mars on different shots with the same setup just shooting several shots in a row. I have been guessing that the size differences must be due to focusing, since I am manually focusing. However, the supposedly "out of focus" larger images look really like Mars in larger photos, even to the point of showing what looks like some surface detail. Here's first example, shot with a D7100, 18-105 lens, iso 1250, 160 sec, f 8. Looks like Mars 20180807_3559.jpg
     
  16. this one is the same night, a few minutes later, f 5.6, iso 1250, 1/2000 sec. despite shorter shutter speed/ f stop, the image is brighter and much smaller. Better focus? 20180807_3573.jpg
     
  17. Yep, I'm going to go with that explanation. I should have thought of that at the beginning.

    It is interesting and somewhat puzzling that the misfocused shots show more apparent detail than the well-focused ones. I wish an optics expert would explain that.
     
  18. How not to photograph Mars - with handheld digital compacts. The image was cropped for a better view
    The movement of the camera was probably less than 0.5 mm while the electronic shutter went through it's paces, and it took an age before the orange light stopped blinking, but the Canon 960 is well known for it's slow processing of data

    Next attempt of course will be tripod plus self timer, tonight hopefully. The settings I was using for these first shots were: full 3x zoom which meant digital as well as optical. 1/3 stop underexposure (set manually in "Settings"). "Center" focus. ISO 200 and the rest were automatically set by the camera. These settings finally brought out the red color of the planet whereas with settings of faster ISO and exposure, the planet was white


    Handheld cropped.jpg
     
  19. As well as I know, it is traditional for longer focal length lenses to focus past infinity.

    That way, with thermal expansion and such, you are sure to still be able to focus to infinity.

    In many cases, there isn't enough depth of field to focus to the stop.
     

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