HF11 with .5X W/A adapter...

[Michael Hintlian]

I'm about to pull the trigger on a .5X Century Optics adapter (HD-05WA-43) for an HF11 and understand that I won't get the full zoom through capability with the adapter. What I wonder is how much zoom through can I expect? Any or some? At what point does the the image quality begin to slide?

Many thanks to all for an amazing forum!

Michael

[Dave Blackhurst]

if it's similar to the CO .55 37mm I've got, you'll get about halfway through the zoom range, and suddenly focus goes completely fuzzy... I'd imagine it will be somewhat camera dependent, I'm speaking from a Sony SR11/12

[Bruce Foreman]

My Digital Concepts 0.45x for 52mm lets me get about halfway, but lets face it. We got these things to expand the field of view on the wide end. And although I took a chance on a $45 product I got lucky as heck. Hooked up to a 42" LCD TV capable of 1080p with HDMI I see no difference in detail with or without the wide angle converter.

Blew me away. I expected to have to come to terms with how much "not good" I could deal with. I ain't partin' with this critter!

[Larry Horwitz]

Mike,

Not your original question, but wanted to throw in comment that Canon wide angle adapter maintains complete zoom range without blur you refer to in Century converter but only offers .7X effect. Razor sharp.

Larry

[Tom Hardwick]

As Dave says - it's camera dependent. The closer the auto-focus works (the more powerful it is) the more zoom range you'll be able to use with the 0.5x in place.

My Z1 has a zoom readout in the v'finder - going from 00 to 99. With my 'non zoom-thru' 0.52x converter in place I can zoom from 00 to 66 before sudden and immediate blurring takes place.

This blur (that I can't replicate in post, especially the highlight effects) makes for a delightful time-line cross dissolve into the next scene.

tom.

[Michael Hintlian]

Thanks to all of you for this help.

I get it...its camera dependent. Does anyone have a HF100/10/11 that they've tried this CO .5 adapter with that can comment?

I agree with you Bruce, what we want is to go wide...but sometimes you just don't have the time to remove the adapter to get a shot that might need a touch of zoom - not asking the world but just a little bit. And I'm under no illusion that these adapters do ask us to compromise IQ...I'm just greedy about what I'm willing to give up (smiling here) and wondered where the IQ break point might be with this CO .5 when zooming.

It may be that I'll simply hop on the Canon adapter with its .7 conversion...but again, I'm big on wide and the difference is enough between the .5 and .7 that I'm giving it a hard look. Also, and this is a minor carp, the Canon comes only in chrome which on a black, stealthy camera looks weird. I'd like to avoid any flashy-ness...but might be forced to suck it up.

Again, this is great feedback and all of it helps!! Thanks.

Michael

[Michael Hintlian]

Dave...would you say you were happy with the results before the focus went fuzzy? And are you happy with the adapter at its widest end? Thanks.

Originally Posted by Dave Blackhurst

if it's similar to the CO .55 37mm I've got, you'll get about halfway through the zoom range, and suddenly focus goes completely fuzzy... I'd imagine it will be somewhat camera dependent, I'm speaking from a Sony SR11/12

[Tom Hardwick]

It might be worth mentioning that the less powerful Canon lens will most probably give you a lot less barrel distortion than the CO. Of course you can zoom in which sacrifices coverage for distortion, but as you say - you're buying this lens to go wide, not to zoom in.

So don't plan on shooting buildings, interiors, telegraph poles, door frames etc with this 0.5x lens - not unless you don't mind them bowing outwards.

tom.

[Michael Hintlian]

Got it Tom...and thanks. I'll be shooting in crowds and so on...so it won't be an issue or even noticable.

Michael

Originally Posted by Tom Hardwick

It might be worth mentioning that the less powerful Canon lens will most probably give you a lot less barrel distortion than the CO. Of course you can zoom in which sacrifices coverage for distortion, but as you say - you're buying this lens to go wide, not to zoom in.

So don't plan on shooting buildings, interiors, telegraph poles, door frames etc with this 0.5x lens - not unless you don't mind them bowing outwards.

tom.

[Dave Blackhurst]

Originally Posted by Michael Hintlian

Dave...would you say you were happy with the results before the focus went fuzzy? And are you happy with the adapter at its widest end? Thanks.

The lens came with a batch of other things I purchased, I thought it might be OK for use in an underwater shell since it's very compact - it's not really an HD lens though... noticeable image degradation IMO. I suppose I'd use it in a pinch

I'm comparing to lenses like the HG series Sony .7x lenses which are full zoom through and noticeably higher quality with multi-element construction. I'd expect the dedicated Canon lenses to be closer to that quality level from what I've heard.

While a good wide angle can be bulky and expensive, if you want your HD camera to still look HD, it's the price you pay.

[Bruce Foreman]

Originally Posted by Tom Hardwick

So don't plan on shooting buildings, interiors, telegraph poles, door frames etc with this 0.5x lens - not unless you don't mind them bowing outwards.

tom.

There's another factor not yet mentioned here. The HF series has a 37mm front thread, but if you step up to a larger size for your lens accessories you do 2 things. Reduce chances of vignetting, and hit more of the central "sweet" area of the aux lens diameter.

It's been a well known fact that most lenses perform better in the central portions of the lens diameter, and some "soft focus" portrait lenses for medium and large format got their softness from control discs that had perforations on the outer half of the diameter so as to introduce a "mix" of greater proportion of the outer diameter to the central portion of the lens diameter. I had one such in my studio and when stopped down so the only part of the lens use was the center, it got "tack sharp" and lost all diffuse softness.

I ordered a 0.45x wide adapter (Digital Concepts) in 52mm rear thread to fit a 43mm Canon HV20 with 43-52mm stepup ring hoping that using the center portion of the aux lens would get me around some of the problems encountered with "el cheapo" stuff. The result was absolutely NO LOSS of image detail from wide to over halfway through the Canon lens zoom range. At the widest zoom NO BARREL DISTORTION either, but at the far end of the telephoto position I could see barrel distortion and definite loss of sharpness. Anyway most wide adapters are not zoom through all the way.

When I got the HF100's I had to order a 37-52mm stepup ring and am getting the same results with the wide angle adapter.

[Tom Hardwick]

Originally Posted by Bruce Foreman

The HF series has a 37mm front thread, but if you step up to a larger size for your lens accessories you do 2 things. Reduce chances of vignetting, and hit more of the central "sweet" area of the aux lens diameter.

This is a very common misconception Bruce. Let's take the A lens (a lens that simply bends the light before it enters the camera's fixed lens) as a simple negative element. This element will have two spherically ground surfaces and the chances of the inner 20 mm being more accurately shaped than the next 20 mm are highly unlikely - though not impossible of course.

So using the light from the entire element gives as good a picture as using the light from a central spot. And remember that an A lens is being used in its entirety - varying the aperture of the camcorder's zoom has no effect whatsoever on how much of the A lens area is used. This is of course simplicity itself to check out.

You're right to say that an A lens that's too small might vignette the image, but that vignetting will just be made sharper as you stop down, and vice-versa. Buyinbg the bigger version as you've done will help allieviate this vignetting - nothing more.

I'm simply amazed to hear that you've fitted a 0.45x DC wide-converter to your Canon HV20 and don't get barrel distortion at the wide end of the zoom. So amazed that I cannot believe it, sorry. If so it suggests the DC lens is a very powerful aspherical element and I'd like to know more. Do you have a link so I could go take a look please?

tom.

[Bruce Foreman]

Originally Posted by Tom Hardwick

This is a very common misconception Bruce.

No misconception. I can't remember which European large format lenses (sheet film cameras) used the "sweet spot" principle in reverse, but I had the Mamiya Sekor 150mm f4 Soft Focus portrait lens for the RB 67 based on that concept that came with 3 "control discs" with different perforation patterns. You threaded the front lens cell off and placed the control disc on the back of the front cell rear element. When stopped down to f8, (using only the central portion) with no control disc the lens was "tack" sharp, the image being as crisp as the 127mm and 180mm lenses for that camera.

Wide open the image was soft with a lot of flare. Now in this lens, as well as the European lenses it was modeled after, the outer portions of the lens elements were deliberately designed to emphasize flare and other lens faults that designers usually fought to minimiz.

The 3 control discs introduced different proportions of the "mix" of outer diameter and the central portion. Each disc was clear at the central area (that would be the area used at f8 so at f8 the disc had no effect). The variable diffusion started coming into play as the diaphragm was opened up.

While the central "sweet spot" was part of the deliberate design of this and a few other lenses, lens tests in the magazine articles I've read through the year cited the fact that most lenses have a central part of the aperture range where they perform best, with best resolution and less degradation due to abberation, distortion, flare, etc.

A lens wide open often does not have quite the same resolution (on test charts especially), but when stopped down 1-3 stops or so delivers better contrast and detail resolution. Take it too much towards the minimum aperture and you enter the territory where the smaller the lens opening the more detail you begin to lose due to a diffraction effect.

As far as a link to the "el cheapo" 0.45x I wound up with, I spotted it on ebay at $49.95 plus shipping, ordered it knowing I was taking a chance. I've seen what looks like the same priced lower (one as low as $19.95). All were listed as Digital Concepts.

In "Deer Watch" the 0.45x was on for the car interior at the beginning and then the shots through the front windshield. I should have used a polarizer to kill glare from the windsheild but there is no distortion as houses and utility poles go by.

In "Vision Quest" the 0.45x was on for the whole thing due to close up working conditions on a steep and slippery hillside. Links to both follow.

"Deer Watch": Deer Watch on Vimeo

"Vision Quest: Vision Quest on Vimeo

[Tom Hardwick]

You're right in all you say about the Mamiya lenses, diffraction effects, performance at different apertures and so on Bruce but I thought we were talking about A lenses, not primes or zooms fitted directly to the camera body.

There's no 'sweet spot' when you're talking A lenses - though there is of course on the zoom or prime to which it's fitted. An A lens simply bends the light before it enters your camcorder's front element, and as such the entire element is used regardless of the aperture set on your lens.

Had a look at Deer Watch and yes, the lack of barrel distortion through the screen is impressive. Easiest way to check for barreling is to fit the converter, zoom to full wide and frame up your TV screen. Vision Quest is completely devoid of anything that shows up barrel distortion.

tom.