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14. Vignetting and the Letus Extreme - Instructional HD Video
3 months ago
I decided that I would share whatever knowledge I have in my brief time with my EX1 and Letus Extreme 35 mm lens adapter by doing a video blog. I am not an expert, but I have logged some serious hours on both of them.

I created my website initially to get my name out to potential clients and sell my television skills as a freelancer. I have found jobs because of this website, but I have also discovered that there is a huge community of people who are interested in producing quality television. Most of them have commented on my videos and sent me comments through my chat room, forum, vimeo and email.

Many people have emailed me and asked me several questions regarding my homemade dolly system, my modified telescope panning time lapsing, features on the ex1, color grading using Magic Bullet and shooting with the Letus Extreme.

I have found it very difficult to email answers to these questions. The best way to help people understand is to show them.

This is what I am planning to do with Video Blog entries. This is my first. I will try to do more as I get some time off this summer.

I have shot this video in the “Surviorman” technique with multiple cameras alone in the wild (where I like to shoot). I decided to answer the vignette question that many people have asked me. I own cheap lenses, so some of my vignetting could be inside the film lens and not in the Letus. This “webisode” details using the EX1’s zoom lens to push past the Letus innards and remove the black on the sides of the frame. It is important that the ground glass window is close to center in the frame as you push through it. You will see that it is not and I need to calibrate it. I did not talk about or fix any of this in the video.

I am currently having trouble with edge sharpness on the Letus. This is because I adjusted the Letus ground glass back-focus and by doing so, the ground glass plate is not perfectly straight anymore. I will try to fix this (or I may have to send it back to Letus).

One thing to look at here is the fact that the EX1 blows the Sony Z1U and the Sony HC3 HDV cameras away in color and general imagery. When I was cutting this together, I could not believe how bad the Z1U looks against the new Sony CMOS chips in the EX1.

I tried to be as clear as possible, but if you have any questions, please use my forum. For more information on the Letus Extreme (or to purchase one) please check out letusdirect.com.

My webpage is located at tomguilmette.com
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  • astute 3 months ago
    Can't wait to see this video. I have a lot of questions regarding the lenses used with Letus products. The main thing I am worried about is that it will obstruct my mobility in the field.

    Having to carry around the extra weight and mounting and unmounting the Letus seems a hassle and keeping it on obstructs using it as a handheld.
  • Tom Guilmette 3 months ago
    i try not to take the letus off. it is a pain, and i do not want to cross thread the mount. i had trouble uploading last night, but the video is on my blog right now.

    link: tomguilmette.com/Site/Blog/Blog.html
    click the top entry.
  • astute 3 months ago
    Ah cool, the video looks good. Very nice narrating and editing. Loved the switching between shots. But damn, such a difference indeed between your old Sony and the new one!

    I use a lot of run and gun shots (filming live events) so not removing it would be impossible because the Letus makes the hard to handle handheld. Having a 35MM adapter would not be an option for me in that case. Too bad :(
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  • Underground Planet 3 months ago
    Great job and great insight. Also a huge fan of Les and what all he does on Survivorman. Was pretty happy he spoke at the Sony Vegas NAB party. Was a bit weird seeing him dressed up and cleaned up though. =)

    Keep up the great work Tom.

    - Ray
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  • Tom Guilmette 3 months ago
    I fixed this video so it should work now.

    The reason I posted this is because I wish someone else explained "zooming through the Letus and the film lens" before I bought my Letus. I did not understand how this worked and could not wrap my brain around the idea of using the camera zoom to push through a prime lens.

    I also address the vignette problem with this device.

    I hope this helps you.
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  • Haidar Hakim 3 months ago
    Very useful video Tom thank you so much.

    I just want to know how can you focus on the GG holder, what is the best way?

    And my second question is how can you zoom in in the 35mm adapter without effecting the focus!

    Thanks again Tom :)
  • Tom Guilmette 3 months ago
    the way the letus is designed, you just push to about 77 percent with your camera and the camera is able to make focus at the ground glass. i do not use anything to achive this. it just works.

    as far as zooming through the lens, it just works. i am amazed at how this contraption works. remember, i just point the camera and take the pictures. i am not an engineer.
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  • [ PIXEL VIKING ] 3 months ago
    Thanks alot for that. I just ordered a Letus35 Mini to go with my Canon HG10 a week ago and can't wait for it to arrive. I was curious about the need to use an acromat in order to be able to focus on the GG. If I have to zoom in 77% too, I'm not going to be able to get focus on the GG without some sort of acromat. Do you use one for your EX1?
  • Tom Guilmette 3 months ago
    i do not use an acromat. i am only familiar with the letus extreme (using it on a sony z1u and a sony ex1). good luck. let me know how you make out.
  • Philip Bloom 2 months ago
    Hi Tom, you do use an achromat, that is what the ex1 kit is. Phil
  • Tom Guilmette 2 months ago
    i had to look it up. en.wikipedia.org/wiki/Achromatic_lens

    thanks for clarifying this.
  • Tom Guilmette 2 months ago
    i just realized that since i originally bought the letus extreme for my sony z1u, letus did not offer the proper achromat.

    since i am now using the letus extreme on the ex1, i need to buy the achromat replacement (which is in the ex1 kit you spoke of) and place it between the letus and the ex1. is this correct? will this fix the edge to edge sharpness problem?
  • [ PIXEL VIKING ] 2 months ago
    I'm not an expert on this, but an achromat is basically just a macro lens which allows you to focus on something that is closer than the camcorders normal 'minimum focusing distance'. Since you don't have a problem with getting focus, you should be OK. Don't know if an achromat does anything to improve edge sharpness.

    Surely Philip will know :)
  • Tom Guilmette 2 months ago
    in the letus's case, the kit they sell does improve edge to edge sharpness. here is the link: adapterplace.com/component/page,shop.product_details/flypage,shop.flypage/product_id,52/category_id,9/manufacturer_id,0/option,com_virtuemart/Itemid,56/


    from the letus website:
    This optimization kit includes a custom achromat lens and a 77mm thread ring specifically designed for the Sony PMW-EX1 XDCAM . This corrects the issues in the Sony EX1 lens and gives you sharp focus across the entire image. This kit is as add-on for the Letus35 Extreme. You must have an Extreme with a removable rear achromat lens for this kit to work. This is a direct replacement for the stock achromat and includes an optimized thread ring specific to the EX1 as well.
  • Philip Bloom 2 months ago
    yep when you got the letus extreme for the z1, as i did originally it had the standard achromat inside it. When you get the ex1 kit afterwards you get a replacement achromat and a new slim fit 77mm ring, when you buy the letus extreme at the same time as the ex1 kit you just get that fitted to it. So Tom do you not have the ex1 kit? It's so worth it.
  • Tom Guilmette 2 months ago
    thanks for explaining this. i am learning more and more about this stuff each day. im sure other people with similar questions will find this discussion helpful too.

    i do not have the kit, but i found it on letus35.com for $350. do i get a discount since i am already a letus extreme customer? did you pay full price for this kit? i emailed and called letus earlier this week and i have not heard back from them.
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  • Stephen Lewis 3 months ago
    Thanks Tom,
    You are such a great help for us!
    -Steve
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  • Philip Bloom 2 months ago
    great video by the way. You are better than me in front of the camera!!
  • Tom Guilmette 2 months ago
    i thought your comments on the ex3 were well done. i am faking some of it, not really knowing how the letus works inside. i just know it makes sweet images.
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  • Pierre 2 months ago
    Sure the EX1 is a higher level camera than the Z1.
    What do you mean by 'blows it away'. Is there a way to describe this?
    Maybe with a side to side comparaison, with and without the letus, now you are in your videoteachingmood.
    I am realy intrigued by your statement, and I understand the quality difference between the 2 chips. For now I don't have the money to upgrade.
    But maybe there is a way in post to do something for the Z1 images? Can you help?
  • Tom Guilmette 2 months ago
    as you know, i own both cameras. when i get some time, i will try to do a vid blog on what you have asked. a few other people emailed me asking me to do a side by side comparison of the ex1 and the z1u with and without the letus. keep an eye on my site for more info when i get some time off!
  • Pierre 2 months ago
    Thank you Tom for considering this. Could be a great and interesting comparaison. Hope you will find some time for this. I'll keep an eye on you. Thnx man. :)
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  • Tim O'Bryan 2 months ago
    Tom, this is a great video. It's extremely informative and easy to watch.

    I've got a much smaller camera (a Canon HV30) and I have been rather worried that there was no way around the vignetting from the lens and adapter. This clears up a lot!

    As always, love your work. Keep it up, I'll definitely be watching!
  • Tom Guilmette 2 months ago
    no prob.
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  • Shaun Walker 2 months ago
    Thanks Tom. Awesome video. I knew nothing about 35mm adaptors before I saw yours and Phil Bloom's stuff. In fact I didn't even know they existed. Now I feel my life will never be complete unless I buy one. Can any of you guys come up with a killer of an excuse that I can use to persuade my wife to let me buy one?
  • Tom Guilmette 2 months ago
    just start stashing small amounts of cash away. trust me, it is worth every penny.
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  • Italo Valerio 2 months ago
    Great job !, the factory no have an great video how to this. Thanks to this work.
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  • Rick Horton 2 months ago
    Is that achromat problem an issue with the Letus Mini? Or the Mini with an HV0? I'm just wondering because I'm confused. If you could Phil, could you explain the situation ( issue ) so I can get an idea of if I need to be aware or concerned. I have the HV20 + Letus Mini. If I need something else to make my images sharper I'd really be grateful to know, and I'd get whatever it is in a Heartbeat.
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  • Brett Clements 2 months ago
    I've subscribed to your site. We're all in the same boat. I think the Letus rips and the X1 tears. Congrats on your work.
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  • Mike McGee 2 months ago
    so with the EX1 at Z77 are you taking full advantage of your 24mm Nikon/NIkkor lens angle of view? or at Z77 do you loose the 24mm angle of view, whatever that might be?

    thanks in advance Tom.
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  • eladbari 29 days ago
    not Like it....LOVE IT! :]
    please make more videos like that, Tom :]
    awesome to see some Pro stuff in action! :]
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  • Noisemaker Media 27 days ago
    Awesome tutorial, Tom. I just got my LEX setup a few weeks ago. Trying to figure some quirks to the lens adapter. Definitely a different approach to shooting. Any other technical advice you may have stumbled on to after this posting on the Letus with an EX-1?
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  • jamar 26 days ago
    you spoke of the zoom which answered my question about that but what about the focus what kind of focusing do you have to do in order to get that crisp look? should you leave you cam at one point of focus and your adapted lens at another? what?
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  • Pietro Impagliazzo 21 days ago
    Do you loose any field of view in Z77?
    Are you really getting the focal length of the attached lenses?

    How about letting the vignetting there just for the extra field of view and adjusting the brightness difference in post?

    Or maybe it's not possible, because the loss of sharpness is too big as well?
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