Having bought the two lens NEX-5 package I might be interested in Sony's Ultra wide conversion lens. Problem is there is barely any technical details on Sony's web site other than it fits on to the 16mm pancake lens. First of all Sony do not indicate what focal length is created or the loss of F stop. Does it create an F4 lens or what?
Any users who can indicate the new focal length, F stop and potential loss of quality as well as vignetting etc.

Just noticed that the converter lens is available for pre-order only so maybe it is not available yet.

Only a few samples have been seen to date. It's not wonderful for edge/corner quality but it works. It is not yet on the open market in most areas.

David

Thanks for that David. It might be that the usable area with the conversion lens is no larger than the regular image using the 16mm pancake. In that case the conversion lens is really pointless. I will wait until it is released and views are expressed as to its performance.

I haven't see the VCL-ECU1 nowhere, and after months waiting for the VCL-ECF1 I finally got one from a HK dealer on eBay for the same price as I would buy it here, SSHH included -Shame on Sony!

I haven't had enough time for playing with the fisheye, December is the busiest month for me, at the lab and with the events, and temperatures in NYC (-7 Celsius this AM) doesn't really help: I'm not really in the mood for take a walk and try my new lens...

I tried attaching an Olympus WCON-08B wide extension lens with a 49-62 adapter. Despite a huge front element this lens only gives 0.8 magnification but a lot of "light gathering". When I attach it to the 16mm there is minimal vignetting that could easily be corrected in PP, but (there's always a but) extreme smudging in the corners & moderate at the sides with the expected distortion. Just for fun, I attached it to the 18-55. At 18, there is almost no vignetting at the corners and mild to minimal smudging. I think there is no way to get around physics. As the light comes from an extreme angle, it can't bend around the well's walls of the pixels at the corners of the sensor - unless you have specifically designed microlenses as in the Leica M 8/9.

Kenneth, all the bending happens in front of the lens with converters, so there is no effect at all on the optical path geometry behind the lens. What you are seeing (I have tested a professional 0.75X converter with a 62mm rear thread via an adaptor on the 16mm) is simply the addition of some corner softness in the converter design, to the existing corner softness in the 16mm.

This softness is not caused by a bad optical design. It's caused by curvature of focus field, but made worse by aberrations which can't be corrected fully in the converter.

All wide-angles (retrofocus) consist of a rear group which, if removed, acts as a normal to short focal length lens in its own right - rather like the rear doublet group of a Cooke type lens such as the Novar or Triotar. The front section of a wide angle resembles what you buy as a wide-angle converter. So a Distagon, as an example, is more or less equal to a Tessar with the front group given a much higher negative power through a series of negative (typically plano-concave rear, concave-convex larger front) groups of increasing diameter. So adding the Sony converter to the 16mm is more or less like 'completing' an ultrawide design.

The secret to using these converters will be simple enough - f/16. Not ideal for sharpness at diffraction level, but essential for dealing with the curvature of field and the added lateral chromatic aberrations.

David

David
Thanks for that explanation. I'll try it at f16 on the weekend and report back if there is an improvement.
Ken

I bought the VCL-ECF1 fish eye converter for the 16 mm as a fun lens. Not used it much but was surprised by the quality of the centre of the image. The edges of a rectilinear fish eye are not an issue! Here is an image that I straightened out a bit in RAW conversion. The original is also on Flickr.


_DSC2886-modified by cunning.tony, on Flickr

The converter seems very well made (in Japan). It has a small hood and a very substantial and effective cap and a rear cap. The bayonet fitting clicks firmly into place when mounting. It is supplied with a substantial case. Unlike the 16 mm lens it is not really light (150 g).

One other thing I noticed was flare, or rather the lack of it. I took a sunrise with the sun in the image in November with the 16 mm and noticed some flare - not irritating really, but it was there. With the fish eye mounted I took several images at midday with the sun at its highest and fully in the image (northern European December sun, not very high) and there was no flare.

pakodominguez gave me an idea and I checked again with ebay. Here is a link to the W/A converter at £92 delivered (excl VAT & duty if applicable) http://cgi.ebay.co.uk/Sony-VCL-ECU1-Ult ... 4cf3dabb86
So the x0.75 converter is now available in the Far East. Sounds like an 18mm lens at 35mm size. Could be useful. If it is as good as AnthonyC's opinion of the fish eye version I will probably purchase one. Question is if I should wait for UK availability. Sony Style has it on pre order at £99.01 incl. VAT. Hopefully the corners are not too bad at 100% if F11 or F16 is used.

AnthonyC, How do you fire the shutter on your NEX when it is being carried by your Maxi-Dopero kite? And how do you know that the lens is pointing in the correct direction? You must be busy steering the kite and firing the shutter at the same time. I guess you have just set camera to Auto exposure and presumably the NEX will auto-focus as well. Hopefully the camera won't suffer from bumpy landings.

IA - I use a Gentles IR device as a remote trigger:

http://www.gentles.ltd.uk/gentled/index.htm

The NEX-5 (not the NEX-3) can be triggered with the gentLED-Shutter, gent360-LED and gentLED-Auto.
I use the Shutter combined with a basic radio control unit. The RC operates two servos (pan and tilt) and the gentLED. I set the camera to IR remote and and mainly use A at -7 or -1.0 EV. One of the joysticks operates the shutter and I set the camera to focus automatically. It focusses and shoots
almost instantaneously.

The kite is not steered, it is a single line kite. It does have to be controlled though and the easiest way is to fix it to a climbing harness, which frees you to walk around. You can also use a sling to fix it to a convenient tree, fence post, railing or bench etc, but then you do not have any control if conditions change. It is not quite as simple as one kite unfortunately, ideally you need a range of at least 4 kites to cover varying wind speeds - no wind no photography - although the Dopero will lift the NEX in near-zero wind conditions.

My NEX-5 has has one crash landing on grass between two rock outcrops. It was completely undamaged. A compact would have had its lens ripped off. The lens hood for the 18-55 mm lens provides some protection (in addition to its intended function) and appears to be designed for the 16 mm as well, at least I have never seen any vignetting.

AnthonyC, Thanks for the information. Just shows what is possible with this little camera.

Forgot to mention that I use a small Swann security camera and transmitter for composition. Coincidentally its field of view is much the same as the 16 mm. This is not strictly necessary though and it means juggling a small monitor as well as the RC receiver and controls and the kite. You know the tilt exactly, because it goes in steps, so that part of the composition is very accurate. Pan is more difficult, but you get used to it and I use an antenna as guidance, sometimes with binoculars. It is surprising how accurate you can be without video. The NEX-5 does not have a video out that is any use for this unfortunately. Nor does it have an intervalometer , which my other cameras used on kites do have.

Warehouseexpress.com now have Sony's VCL-ECU1 Ultra Wide converter for E-mount 16mm Pancake lens in stock at £99.00 http://www.warehouseexpress.com/buy-son ... r/p1520703

I would be very interested in comments on the performance of this converter. Does it reduce the IQ of the 16mm lens? My 16mm has been sent to Sony as it is abysmal. If I get a good lens back I would be tempted to fork out on this converter.

The other issue is does anyone know if it will fit on to 18-55mm E-mount as well? This lens reduced to 13.5mm (or near enough 21mm 35 size equivalent) could be quite useful if retaining acceptable sharpness.

The fish eye fits on the 18-55 mm. I would not have bothered, but Sony warns against it, so I had to give it a try! There are no electrical connections so I could not see what possible harm it could do. It fits ok (the mount is the same as the 16 mm). The results are entertaining and could be useful on rare occasions. Difficult to describe but at one end of the zoom you get a circular image with a halo around the centre. Totally useless for any normal photographic uses though and I expect the wide converter will be little better on the 18-55, but I'm not certain. It is still not in stock here.