HV10 comparision standard / Raynox HD-5050PRO lens

[John Hinkey]

Originally Posted by Bert Na

If it's any consolation, you're not the only one who's disappointed with the image quality of the wide angle adapters on the market. I bought a Century Optics 0.65x for my HV10 thinking that its Schneider optics will yield good results but at its widest setting, it's got the same issues as other less costly units: barrel distortion, poor corner sharpness, & optical vignetting. Mechanically, it's ok: it's fairly compact, has filter threads, it fits directly on the HV10 and has zoom through capability. Canon should consider extending the wide range of the built-in lens, many of us are willing to pay a little more for the feature...

Bert - It appears that you have a filter of some type in front of the WA converter - did you try things with this off to see if the sharpness/CA in the corners improves?

- John

[Tom Hardwick]

I've never known a filter to reduce sharpness (unless it was smeared with vaselene for that express purpose) but I have seen them vignette the image corners and I have seen them add considerably to the lens flare.

tom.

[Bert Na]

I always use high grade filters with my lenses, in this case a low profile B+W filter, and never had a problem. In any case, I took a couple of shots with the filter removed, and it made no difference: The center region, roughly 60%, is sharp but the rest of the image is blurred. Could someone post some samples shot with a Canon wide angle adapter?

[Tom Hardwick]

Bert - I've just had a thought. Are you using the camera /widie combo in the auto-focus mode? I'll take a guess and say yes, because I see the same 'whoosh' edge effects with some of my converter lenses.

Might be worth trying this. Place your camcorder/widie combo in the auto-focus mode about 3 feet from something contrasty and then lock the focus at that distance. At all apertures and at wide-angle you may well find the image quality improves noticeably, the DoF covering everything from element front to infinity

If you zoom in things will deterioriate of course, but then I've always maintained a wide-converter is for wide shots, and anything else should be done by your unaided zoom.

tom.

[Tom Hardwick]

Oh-oh. I've had another think. Your second shot is just that right? A 3 foot close-up of the get-fit notice, yet the edges are quite poor. And the barrel distortion is nothing short of horrible. Doesn't look like a good combo to me.

[John Hinkey]

Do you think it's just a bad/defective WA converter or would ALL of these models perform poorly? The Century optics web site specifically lists the HV10 for this converter (but perhaps only because it shares a 37mm filter thread) and some other threads have indicated that Century optics are typically best in their class (mayber they are in the low class though).

- John

[Ron Chau]

There is another older post in the FX1 section with sample pics of the Century non zoom through. It was either a .5x or .6x, I don't remember. But I do remember the pic. Big time barrel distortion.

http://www.dvinfo.net/conf/showpost....8&postcount=10

[Bert Na]

From what I've seen online, barrel distortion may be a common problem with wide angle adapters: Pana DVX100 with Century Optics WA adapter, how about this sample with the 0.55x Century Optics adapter. Edge sharpness seems to be a common problem too, although the poster of this sample of a Tiffen 0.56x WA converter says that he finds no edge sharpness issues with the lens, the loss of resolution at the edges looks pretty obvious to me.

[Tom Hardwick]

Barrel distortion is indeed a common problem with wide-angle converters. In fact most camcorder zoom lenses barrel distort pretty horribly down the wide end on their own, and a converter lens only adds to this.

Simple test. Stand a few feet from your flat-screen TV, zoom your camcorder to full wide and move so that the TV frame (either 16:9 or 4:3) fills your v'finder. See the curvy edges? It's your cheap camcorder lens doing that.

The only way to combat this barrelling is to abandon all thoughts of zoom through converter lenses and fit a single element aspheric.

tom.

[John Hinkey]

Tom - Do you have any suggestions for a single element aspheric? Is this what you mean: http://www.schneideroptics.com/ecomm...=1069&IID=1754

- John

[Tom Hardwick]

That looks to be a very interesting lens John, especially so if their claim that it is ''without noticeable distortion''. Trouble is they don't mention anywhere that it has an aspherical surface, and that makes me suspicious of their claim. Very suspicious. Aspherical elements are very much more expensive to grind and every single sperical element I've used has increased my barrel distortion - regardless of the camera I've used.

Still, I'm not one to make claims without having made tests, so all I can say is that someone (you?) should. But I'd want a water-tight returns policy in case it did just happen to add barrel distortion.

These people make proper aspherics:

http://www.lenswvl.com/
http://cinematechnic.com/products/ze...6mm_Zeiss.html
http://www.wittner-kinotechnik.de/ka...a/b_optike.php
http://www.wittner-kinotechnik.de/ka...a/b_optike.php

I have the Bolex Aspheron. It's big, powerful (0.52x) beautifully T* coated and takes my Z1 down to a non distorted 17 mm (35 mm equiv). Now that's a focal length to make Krubrick sit up and take notice.

tom.

[Tom Hardwick]

John - I see on that Schneider site there's an 'ask a question' box. So I've asked:

Your .55x wide adapter 37mm.

1) Is it glass?
2) Does it have an aspherical surface?
3) Is it available in other thread sizes?
4) Is it multi-coated?

Kind regards,

tom.

[John Hinkey]

Tom -

Thanks for asking Schneider those questions. On a related note to one of my other threads - is there an advantage to using a WA adapter that is larger than you need so that you aren't using "all" the glass? I've read a few posts where people have reportedly used, for instance, a 49mm WA adapter when all they needed was a 37mm and claimed improved corner sharpness.

- John

[Tom Hardwick]

BTW John - my 'is it glass?' question comes about because aspherical surfaces lend themselves to plastic high pressure injection moulding techniques, and Schneider they call their 0.55x a 'lightweight'.

I can't see any reason whatsoever to use the 'centre of the element', unless of course the edge is scratched, not coated, unpolished or dirty. My guess is these people are seeing better definition because they think they should, and because they're shooting at better apertures and focused distances.

When you've got a wide-angle on it's imperative you avoid small apertures as diffraction losses are far more obvious at short focal lengths.

tom.

[Bert Na]

This is one of the lenses that I found a posted sample image. Its barrel distortion is certainly nothing to get excited about...

Originally Posted by John Hinkey

Tom - Do you have any suggestions for a single element aspheric? Is this what you mean: http://www.schneideroptics.com/ecomm...=1069&IID=1754

- John