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LA-7200 Anamorph Lens Diopter
  • jaecjaecjaecjaec
    I've got a couple of LA-7200 adapters to play with. Despite search the internet, I'm a bit confused over what diopters do exactly. Specifically where to place the diopters. So, I did this quick experiment. It's clearly quick and crude for reasons that I only had one hand free to hold the lens in place, and one to take a snap shot. This is done on a camcorder Canon HF-g10
    1. Zoom out, native lens
    2. Zoom out, native lens, +1D in front
    3. Zoom out, LA7200
    4. Zoom out, LA7200, +1in front of the LA7200
    5. Zoom out, +1D between the camera and LA7200
    6. Zoom in with LA7200 only
    7. Zoom in with LA7200, +1D in front
    8. Zoom in with LA7200, +1D between the lens and LA7200

    I know these pictures are crappy, but am I correct to say that using a diopter between the lens and the la7200 work? It seems to not work as powerfully as putting it in front of the LA7200, but it works? Photo 6 is out of focus, photo 8 is in focus?

    This is important to me, and perhaps others, since large, good quality 0.5 diopters are so rare and expensive. 68mm, higher power diopters, such as +1 or +2 may work just as well....
  • 45 Replies sorted by
  • Xenocide38Xenocide38

    @HoneyColour I have the Nikon 80-200mm and it works great with the GH2 for video. Granted it's VERY telephoto but it works.

    As far as the 80-200mm with the LA7200, it'll work but the 80-200mm already has a limited close focus, and then the LA7200 makes that even worse.

    On my blog I posted some breakdowns of using the LA7200 and in Part 2 I tested the Nikon 80-200mm with the LA7200

  • HoneyColourHoneyColour

    Thanks itimjim! But the max aperture is 5.6... I tested the Hexanon 50mm 1.4, I don't have the right adapter for it, but it happenned to squeeze onto my Nikon G adapter. Bokeh looked great! But couldn't get to infinity... Will probably sell it.

    Anyone try a Nikon 80-200 with the LA7200? Any particulary filmic shots that can be achieved with it?

  • itimjimitimjim

    The Panny 14-42 is actually quite a nice match with the LA7200 as its max aperture is f4.

    I've stuck mine on the front of a Tokina 28-80, and if works (looks awesome too), but again keep it f4 or less.

  • HoneyColourHoneyColour

    Hello all, have any of you used the Nikon 80-200mm 2.8 AF-D with the GH2 for video? I am thinking about buying a nice used one... I would be attempting to use it with the anamorphic adapter AG-LA7200 and a Tiffen Series 9 +0.5 close up, as well as a Cokin P +1, +2, +3 etc...

    Also any suggestions for great lens combos for my anamorphic set up? I have:

    -Panny 14mm -Nikon 35mm 1.8G -Hexanon 50mm 1.4 & Nikon 50mm 1.8D -Panny 14-42mm (not sure if I'll get nice vid with this one).

  • kavadnikavadni

    @radikafilm, yes precisely. If you want to try and work out theoretical distances, with a 2x adapter you have to work with two DOF tables. If your working with a 25mm lens, you consult a 25mm DOF table to work out what will have an acceptable vertical 'circle of confusion' and a 50mm for the horizontal. The useable DOF is where the two overlap.

  • radikalfilmradikalfilm

    @kavadni Hi, thanks, I retested and it does help quite a bit in the range of 0.5-1m. At 1.2m it becomes useless and it makes matters worse at longer distances. The exact threshold presumably has to do with the focal distance of the lens behind (29mm x1.86crop=54mm)?

    Optical physics aside, unless I get a +0.3/0.4 diopter this one is good for extreme CUs only.

  • kavadnikavadni

    @radikalfilm The +1 might be too much, how do objects look at 1m?

  • radikalfilmradikalfilm

    Ok so I have a Cokin +1 in front of the LA7200 and I'm getting WORSE focusing than without it! Behind the anamorphic I have a 29mm fixed lens opened at f2.8 and 2.5m away from the focus point. The situation doesn't improve if I stop down the lens.

    What might be going on? I'm actually ok with the sharpness without the diopter (+ the larger field of view) but the theory doesn't match my practice.

  • maxmizermaxmizer

    Reading around and not being able to test, what is the best way to improve ag la7200, in front of or behind

  • kellar42kellar42

    Got the LA-7200 in the mail today and am definitely loving it. Does anyone have a workflow for unsqueezing in FCPX? Thus far I've just been messing around, and dropping the 'Y' axis under scale down to 77% seems to do the trick perfectly, but I want to verify that I have that correct!

  • JohnBarlowJohnBarlow

    Peoples are looking for rare 0.5 and 0.25 dioptres?

    Don't forget that dioptres add, so for example

    +3.0D + (-2.5D) = 0.5D, and 3D and -2.5 D not so rare :)

    best ones are achromats and some are cheap in surplus stores like SurplusShed

  • ishvarishvar

    OM-D EM-5 with LA7200

  • Xenocide38Xenocide38

    @itimjim the LA7200 works well for me in a film setting where I have full control over the variables and have time to adjust. The diopters do their job and they have limitations but it's almost always better than the stock LA7200. For infinity focus I just take off any diopters. I've gotten some good results from the LA7200 and while it's certainly not perfect, most of the time I'm able to "correct" the problem I am having by some other means. I wrote up a Part 2 about the LA7200 on my blog if you want to check out more specifics.

    http://stronzvanderploeg.net/2012/08/10/anamorphic-shooting-with-the-la7200-part-2/

  • goannagoanna

    http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=271024253869

    and

    http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=271024114611

    $350! These 100+mm diopters are expensive.

  • itimjimitimjim

    @kavadni I have one, but they are very rare. Best you can do is create an eBay search alert.

    @fabro106 I think you're really going to struggle. If I remember rightly, Canon make a large diopter (105mm) but it's mega-bucks, like £400+. Regular round diopters go up to about 77mm, which you could use with a step down ring.

    @xenocide38 How are you getting on with your LA7200? Diopters don't help if your filming at infinity though, and you'll still suffer softness, especially in the corners. I've used the Cokin P101, the Heliopan 0.25 and the Tokina 0.4 and it's still only performs will in certain situations.

  • fabro106fabro106

    guys, i really need your help, can anyone tell me what diopter fits in my isco ultra anamorphic 2x? is 92mm across the inside diameter. thanks

  • kavadnikavadni

    Could somebody point me towards heliopan +0.25 .. I can only find +1 +2 and +3

  • Xenocide38Xenocide38

    I've had my LA7200 for a year or so now but haven't used it very much. Finally got around to testing out some of this stuff for myself and wow does it make a difference. I did a full write up and you can see how I rigged the close-up filter in front of the LA7200: http://stronzvanderploeg.net/2012/04/26/anamorphic-shooting-with-the-la7200-part-1

    Overall I'd say: you're not going to want to use the LA7200 without some kind of diopter system in place. It makes that much of a difference!

  • itimjimitimjim

    How do you get on with shooting wide with filters. I've offered up a 4x4 filter holder to the front of the hood and it vignette's at 14-18mm. Once the built in hood was chopped off there wasn't a problem.

  • soundgh2soundgh2

    Cinetactics make an La7200 sized front mattebox that will hold Cokin sized filters or diopters

    http://www.cinetactics.com/Page.bok?template=c_mb145a

    I have the non anamorphic one for a sun shield - they're light!

  • plasmasmpplasmasmp

    I want to buy a Bolex 16/32/1.5x or an Isco 42 but they have dried up it seems. We have an Isco 36 and that's fantastic down to 35mm

  • itimjimitimjim

    @plasmasmp Thanks for the advice. I've just tried the Tokina .4 in between the 14/2.5 and the LA7200 and there's an improvement in the edges. I was quite happy with it anyway, but that's quite nice. Ironically it had trouble focussing close-up. I wonder if this might work for the 20/1.7 too?

    Based on your video, I've just purchased a Heliopan +0.25 Close-Up 52mm, so I'll give that a whirl sandwiched between the LA7200 also.

    If you ever get the chance to try out a Bolex 16/32/1.5x, do it. I love the convenience of single focus (and auto when necessary) of the LA7200, but the difference in wide open quality is astounding in comparison. Just a shame the widest lens I can use is 28mm. I'll post a comparison video when I get chance.

    I've not noticed the difference in sharpness handling on the GH2. I always presumed the Panny glass was super sharp due to the coatings. I'm currently looking at diffusion to try to soften them up a bit, possibly a Tiffen ULC. Filters aren't the easiest thing in the world to use with the LA7200 either!

  • plasmasmpplasmasmp

    I'm sure it works with the 14mm 2.5 but you're going to have more CA and barrel distortion. The other problem is that with electronic lenses, the sharpening seems to be more noticeable when the picture is unsqueezed resulting in more noticeable aliasing on the GH2. If Vitaliy finds a way to disable the sharpening completely with 4/3 and m4/3 lenses, I would try and get the Leica 14-50 or the Oly 14-35 working with this method. The Tokina .4 also helps at longer focal lengths to sharpen the lens by mounting it in front and sandwiching the la7200 with the .25 in the rear and the .4 in the front. Downside being you've greatly limited focus distance unless stopped down.

  • itimjimitimjim

    @plasmasmp have you tried the 14/2.5 pancake combination, as I find this lens works well wide open. It's "crazy" wide though :-)

    I'm going to have ago mounting my Tokina 0.4 Achromat in front of the LA7200 to see what results it yields.

  • plasmasmpplasmasmp

    When you go up to 4k, you need to be at f5.6 to full resolve that much detail, but even at f4 it has a nice soft FD/Pre Ai look to it

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