Unanswered concerns on TWONEIL or any other budget adapter (recommendations?)

M

Marshallarts

Well-known member
I just posted this at www.HV20.com but since that site is overrun by the more amateur crowd I thought it appropriate to ask here. Before I go out and buy a EX1 or 3 w/ adapter, a Canon 5D, Scarlet, or any other more expensive camera to build my reel I wanted to consider trying a DoF adapter on my HV20, a much smaller investment for what could yield similar results for a reel. Why drop the big bucks before I have a gig... Though I only have a HV20 please keep reading, I mostly AC and simply never needed to buy a 'real' camera. -----

A few months ago I tried emailing TwoNeil regarding specific concern before going ahead and purchasing his adapter. Typically I work with higher end cameras and accessories (Sony F900 + P&S Pro35 adapter when needed) and wanted to make sure my concerns were addressed on this lower-budget level. Of course I understand the this rig is MUCH less expensive and one can't compare but this is all I can afford to own. I don't need a comparison, I just mention my past experience to show my concerns are genuine and real given my knowledge and experience.

Below I have pasted my original unanswered email. I would really appreciate any effort you have in answering me these questions:

Hi there,

I've been holding out way too long... There's just been a few questions I can't get solid answers on. I've searched everywhere and have found some conflicting opinions (many from people who don't know much). Can you please answer these questions for me?

1. First off, on your website only mentions using it with a 50mm or 85mm lens. Is there a reason to exclude others (such as vignetting)? I've seen other demo's that claim to use a 35mm lens. What is your experience with these wider lenses? Do you have a problem with vignetting? Why do you suggest only the 50 and 85mm?

2. The achromat issue... I've read both sides arguing you need one and you don't. What do you suggest? Can you "REALLY" see chromatic aberrations or other image issues without one on an HV20? I can't tell by the small sample footage I've seen.

3. How big is the ground glass inside the adapter? Is it a full frame 35mm ground glass? Or a APS sized (Super 35mm in motion picture)? I've made a few threads address the effect this has on DoF since I don't prefer the super shallow look most people go for shooting wide open on these adapters. I prefer it stopped down a bit--a DoF more easily acheived on a smaller sensor/ground glass or would that effect optical quality from 35mm full frame still photography lenses? Or Is it possible for me to zoom in a bit to achieve this or will I see grain?

4. Is vignetting a problem ever? I've questioned this user about this video and how he had such vignetting problems. Oddly I feel the vignetting is why people commented so much about why they liked it, I think to some people they thought it looked artful. The user says he had a 35mm lens on it, is that what caused it? The vignetting is VERY prominent.

Sorry to take up your time. I greatly appreciate it if you could answer those questions. Looking at that link you can see I've been searching for an answer since the beginning of October.
 
I can't answer for that specific model but here are the general answers based on what I know

1. Wider lenses vignette more and tend to have soft edges. On adapters with poor edge to edge sharpness, it's not a good idea to use wider lenses. My 24mm f2.8 has VERY soft edges on my Letus Extreme, and I don't use it often.

2. You need an achromat. Besides correcting for CA, the simple reason is that without an achromat, you can't focus on the ground glass.

3. The ground glass inside adapters tend to be larger than 35mm, certainly larger than APS. But you will have to zoom in to clear vignetting, and that'll limit you to Academy or Vista size frame. Again, it'll depend on the adapter. On the Letus Ultimate you can zoom in all the way and not lose sharpness; on the Extreme I can only zoom in within a certain range before the image becomes too soft.

4. Vignetting is always a problem, but it depends on the lens. On an adapter you need to note the minimum zoom number to clear vignetting on the image.
 
i've got one of his adapters
im using it without an achromat with the DVC30 and i can focus on the GG fine, im not sure about other cameras though, aside from the hv20/30
I believe the ground glass in mine is the Canon Ee-A
http://www.bhphotovideo.com/c/product/402203-REG/Canon_0828B001_Ee_A_Standard_Focusing_Screen.html
or it might be the Ee-S. Regardless, the GG is that size
i've been using a 50mm f1.8 and a 28mm f2.8
Huy Vu is right about the wide lenses being soft around the edges but it is not too bad, or at least to me.
the vignetting isnt too bad but I do find it annoying sometimes.
 
Check out www.vimeo.com/1614485 where you will see the adapter on the HV20 and footage shot with it. You'll also see some footage using the equivalent of a 16mm lens and a 400mm lens mounted on the adapter with the HVX200. You can email me and I will give you more info on the HV30 and the adapter. You'll find the email on the vimeo site.
 
Thank you all for your great feedback. Sounds like this adapter is pretty good compared to other adapters especially for the price! It's a fraction the cost of the Letus Extreme which appears to still suffer issues.

My concern was how poor a $200 adapter can be. (And those specific questions I rose that were flags to me).

If anyone has anything else to add I'd appreciate it.

Thanks again
 
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