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DrJohn last won the day on October 13 2018

DrJohn had the most liked content!

About DrJohn

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    Advanced Member
  • Birthday 08/27/1948

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    Northport, NY
  • Interests
    Medicine, Physics, Astronomy, Photography

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  1. I used the Sigma 150-600 mm lens with MC-11 adapter for Sony to image the moon. The image came out ok. But, there was significant cropping. I wanted more focal length. Sigma said I couldn't use the 1.4x or 2.0x teleconverter with this lens and the MC-11 adapter. They gave me the wrong info. You can use the teleconverters. However you will lose the autofocus. If you're imaging the moon, you will use manual focus anyway. I just came across this youtube video using the 150-600 mm with the 2x teleconverter on a Sony A7RII. John John
  2. I'm selling my Sigma 100-400 with MC-11 and Sigma 150-600 mm with MC-11 and getting the Sony 100-400 with 2x. Both Sigma lens are sharp. However, you cannot use a teleconverter with either of them. I want the 800 mm for imaging the moon. http://www.drjohnphotography.com/used.htm John
  3. I've had this problem many times. Usually, the telescope doesn't have enough back focus. Sometimes the T-adapater needs to be longer. Sometimes, shorter. Sometimes I've given up with that telescope. I would call Lunt and tell them which telescope and camera you are using. Maybe they can make a suggestion. John
  4. That's a great shot. And, handheld! John
  5. It's a desperate attempt by Nikon to catch up to Sony. But, they have a long way to go. I love my A7RIII. John
  6. I've completely gone over to Sony after using Nikon since the 70s. I have the A7RIII. It is an incredible camera. John
  7. Sure I considered it. But, I don't have the energy any longer to climb. I'm still dealing with the after affects of Lyme disease. John
  8. I was hanging from a cliff to get this shot and holding the camera as low as possible to see through the bushes. There was only a small opening in the bushes. No processing done. John
  9. Makamah Nature Preserve - Northport, NY. October 31, 2018 Sony A7RIII, Sony 28-70 mm lens at 28 mm.
  10. Sony A7RIII, Sigma 100-400 mm lens with MC-11 adapter at 400mm
  11. I'm a convert from Nikon so I'm not used to the Sony A7RIII. My thumb keeps accidentally touching the exposure compensation dial and messing up my exposure. Is there a way to disable the exposure compensation dial? John
  12. There are more focal lengths shown on this post: John
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