Tips for a mirror lens

Discussion in 'Adapted Lenses' started by ErickSaint, Jan 21, 2013.

  1. ErickSaint

    ErickSaint TalkEmount Regular

    Aug 27, 2012
    Milwaukee, WI
    I know they are not really ideal, but really considering one. I've got a minor interest in astrophotography. Today was super clear with an excellent view of the sky, but it's -17 degrees with the wind chill. Looking up it got me to thinking about the mirror lenses. There are some Samyang 500mm with 2x converter and some other things for around $150 on ebay.

    Has anybody ever used these with the nex system? Was it worth the money?

    I have a friend that I'm getting a 200mm Rokkor from, need to meet with him to pick it up one of these days. Just not sure if 200 is long enough for really good shots.
  2. Phoenix

    Phoenix TalkEmount Top Veteran

    Aug 25, 2011
    Melbourne, Australia
    Phoenix Gonzales
    I still have my 500mm F8 Rokkor Mirror lens

    This is what it looked like attached to my old NEX-5


    If you are planning to shoot astrophotography and shoot heaps of photos of the moon there's really no limit on how long your lenses are, from my experience I found it challenging to take photos of the moon with a 500mm on the NEX-5, as the field of view is really narrow as opposed to a zoom lens where you can start off wide and zoom in to your target subject.

    The set up is also prone to shake even with a sturdy tripod which can't be helped due to the NEX's light weight and small body, even when mounted on a tripod I still shot on low light handheld mode to alleviate camera shake.

    This is a photo I took with this lens attached to a 2X teleconverter


    I find that you sacrifice a bit of sharpness, detail, and structure when using a teleconverter to multiply your focal length. I think the shot of the moon did not come out as sharp as I wanted due to camera shake and the teleconverter.

    Worth the money? it really depends, the set up tends to be a one trick pony but if the majority of your photography is astrophotography then you'll get good use out of it. I wouldn't personally buy one for the NEX as astrophotography isn't really my thing, the lens itself is a remnant of my lens collection during my film shooting days (literally a legacy lens) where I used it to shoot birds and wildlife, all I had to do is buy a $9 teleconverter to check it out.
  3. quezra

    quezra TalkEmount Top Veteran

    Aug 22, 2012
    200mm (300mm equivalent) is neither here nor there - a really bad length in my opinion. The moon still looks relatively small though you can get a bit more detail out of it than the naked eye. I am nowhere close to an expert on astrophotography, but tried a bit of it this past Christmas with 3 different cameras - NEX-5N, Canon SX50 HS (1200mm!) and Panasonic FZ200 (600mm).

    For milky way shots, the wider the better. For constellations, 35-50mm are great (and 50mm is great particularly because you can find cheap fast lenses. At 600mm the moon was very nicely filling the frame. At 1200mm, I could just about get a blurry image of Jupiter and 4 moons (it looked like a big blurry dot with 4 smaller blurry dots on the sides). But to get things like nebulae, you need pitch black skies (actually this is the hardest part), really long exposures (and that means getting a tracking mount), as well as liberal use of Deep Sky Stacker.

    Manual lenses are much easier to focus than AF, which was the bane of all 3 cameras for me. I had the Sigma 19/2.8, 18-200 LE and 50/1.8 and the only ones that I could get any results from were the 50/1.8 shooting constellations. I really wished for my FL55/1.2 but didn't bring it for the trip.

    800mm I suspect is going to be really hard to use for reasons Phoenix pointed out - most mirror telescopes come with guiding viewfinders that are much wider to do your main framing, and then fine adjustments in the main lens (a tripod with a panning grip was also sorely missed on my attempts).
  4. ErickSaint

    ErickSaint TalkEmount Regular

    Aug 27, 2012
    Milwaukee, WI
    Thanks guys. It was just a thought I had. The other thought was getting some sort of hobbyist type telescope and the proper t mount adapter. But that kinda breaks a price point that I would be looking at. Not sure how much I really want to put into this, as I said it's just a minor interest at this point, and would be nothing I probably pursue until spring when the temps come back.