G1 + wide converter

I connected Canon's WC-DC58N 0.7 wide convertor lens to the 14-45 G1 kit lens (using a simple adapter).

The observations I want to share are :

1/ Focal distance can be decreased below 12mm, at lower focal distances the corners darken

2/ Barrel distorsion has to be corrected, e.g. in PS, but no basic issue

3/ No particular issue which chromatic aberation neither (a very small correction may apply)

4/ Half a stop additional loss

5/ I am still evaluating image sharpness, some bluriness seems to appear in the corners.

Despite the Canon WC is huge, the combination with G1 & 14-45 kit lens is quite workable and might be a low cost, reasonable IQ (image stabilized) alternative in cases where 14mm is at the long side (in my case mainly for occasional interior photography).

I would be glad to learn from other peoples experience with wide angle optics in combination with G1/GH1.

Hereby a small update :

I also tried the Miinolta ACW-100 0.8 converter as suggested in :

http://forums.dpreview.com/forums/read.asp?forum=1041&message=32914674

It is basically a much better combination with my G1 + 14-45 than the WC-DC58N and results in a decent 22.4 (35mm equivalent) stabilized wideangle. I observe nearly no barrel distorsion (for most of the pictures I even do not correct) and no corner falloff. Pictures can be used out of the camera and basically the IQ is very good and fully meets my prosumer expectations. The converter is also easy to mount and does not require to expose the camara interior to environmental contamination.

The converter is of course not small, but easily fits in an SLR holster bag (vertical position, camera side down) with the G1 + 14-45 on top in horizontal position. I find it very compact and convenient way to carry my gear.

I have been experimenting with the cheap 0.45x wide angle adapter from "Digital Concepts" that I was using on my videocamera and my Panasonic 20mm f1.7 lens.
The results are much better than I could expect.
This is a jpeg straight out of the G1 (only resized in PS)



In the next one the lines were distorted, so I had to apply a 12% correction in PS



It seems to me that the results are quite acceptable for an almost free superfast superwideangle lens!

For my money, pbar's suggestion re the Minolta ACW 100 wide converter in the second post is far and away the best option if you're looking to put any kind of wide converter on the 14-45 Panny zoom. The idea was first suggested many months ago by Frank Jones of Melbourne, who posted photos of the rig and sample images here:

http://forums.dpreview.com/forums/readflat.asp?forum=1041&message=31768490

I can attest to everything pbar says about the image quality and overall size of the combination when mounted on a 14 to 45 zoom with a G1 or GH1. Keep in mind that the Minolta ACW is no longer in production, but it is still often available used online. And even brand new and boxed for $129:

http://igadgetnow.com/konicaminoltaacw-10049mm08xwideangleconverterlensfordimagea1a2anda200digitalcamerasacw100.aspx

You will need a low-cost 52 to 49mm stepdown ring. You get an effective FOV of 22.4mm, f/3.5, and you can do limited zooming on the wide end so that you can easily shoot at an effective FOV of 24mm if desired.

About attaching wide converters to the 20mm f/1.7 pancake: You should think twice about it because, unlike the 14-45 zoom, the front element of the pancake moves in and out for focusing. The additional weight of a wide converter MIGHT cause the focusing motor to burn out. But IF you want to forge ahead, consider using the Panasonic wide converter DMW-LW46, designed expressly for the Panasonic LX3 camera. This one screws directly into the 20mm f/1.7 filter thread, converting your effective FOV of 40mm into roughly 30mm, with f/1.7 max. aperture. Ideal for those who crave a low light, semi-wide alternative to the effective FOV of the 40mm f/1.7. Optical results are superb, but BE WARNED there could be mechanical/electronic consequences.

Thank you for your warning.
I am not using this combination every day, so the risk should be reduced.

Hi,

I'm using a Raynox 7900ZD with the 14-42 in my e520 (I plan to upgrade to µ4/3 soon), and the results are very good. iḿ quite happy with the combo.
you can see it here: http://raynox.co.jp/english/dcr/dcr7900zd/index.htm

It comes with a 62mm thread and an 58mmm adapter, and I can reach 11mm (22mm eq) with no corner darkening. The only problem I see is tat it has to be used with internal focusing lenses, since the raynox is heavy.

Itrofnoc said:

Thank you for your warning.
I am not using this combination every day, so the risk should be reduced.

Click to expand...

/pedant/
No the risk is the same! The exposure is reduced! ;-)
/pedant off/

Interesting pictures, though! Thanks for sharing.

Mike
--
Mike Davis
Photographing the public for over 50 years
http://www.flickr.com/photos/watchman

For everyone's information,

if you put a .45x wide converter on the lens and shake what would be the equivalent of 10 pixels without the converter, the wcon will make the image move only 4.5 pixels, but the 14-45 lens will still correct 10 pixels, so you will have 5.5 pixels shake blur with OIS on and only 4.5 pixels shake blur with OIS off. (And this assumes the OIS doesn't introduce blur of its own).

So the general advice is that, at least for wcons 0.5 and wider, turn the OIS off.

Also, with 0.7 and 0.8 wcons, the OIS effect will be reduced so you may have to use slightly faster shutter speeds than you would expect, relying on the OIS.

William Ing said:

But IF you want to forge ahead, consider using the Panasonic wide converter DMW-LW46, designed expressly for the Panasonic LX3 camera. This one screws directly into the 20mm f/1.7 filter thread, converting your effective FOV of 40mm into roughly 30mm, with f/1.7 max. aperture. Ideal for those who crave a low light, semi-wide alternative to the effective FOV of the 40mm f/1.7. Optical results are superb, but BE WARNED there could be mechanical/electronic consequences.

Click to expand...

THANK YOU very much for that hint! I had thisone in the closet but never hat the idea to try this combination, simply because the LX3 has a so much smaller chip. The DMW-LW46 is much smaller than other converters I tried, so the risk may be small.

Ehrik said:

For everyone's information,

if you put a .45x wide converter on the lens and shake what would be the equivalent of 10 pixels without the converter, the wcon will make the image move only 4.5 pixels, but the 14-45 lens will still correct 10 pixels, so you will have 5.5 pixels shake blur with OIS on and only 4.5 pixels shake blur with OIS off. (And this assumes the OIS doesn't introduce blur of its own).

So the general advice is that, at least for wcons 0.5 and wider, turn the OIS off.

Also, with 0.7 and 0.8 wcons, the OIS effect will be reduced so you may have to use slightly faster shutter speeds than you would expect, relying on the OIS.

Click to expand...

Hi Ehrik,

I have a Raynox 0.79x (I posted some info above) in a e520, and while I agree with you that the usefulness of the IS will be reduced, in my case it still made a difference, and my pictures were sharper with IS on. They were taken with ~1-2 sec exposure at 11mm (the camera believed it was 14mm). Of course, that's my experience, YMMV.

Dear William,

I think the effective f-number will be 1.3, since you are reducing the focal length, but not the aperture diameter. What do you think?

William Ing said:

For my money, pbar's suggestion re the Minolta ACW 100 wide converter in the second post is far and away the best option if you're looking to put any kind of wide converter on the 14-45 Panny zoom.

Click to expand...

Compared to the 0.45 converter, why is this a better option? Serious question Thanks!

I actually started experimenting with a Canon 0.7 converter (which I used with a Powershot G6) - see my original post. Compared to the ACW-100, the IQ is a lot less.

Reasons might be many and can apply for any other lens (list not limited) :

• The lower the conversion factor, the more difficult it is to design the lens with minimal distorsion and vignetting

• The design objectives : The Canon (which is a little bit bigger in size than the Konica Minolta) is designed to go from 36 to 24 mm (in 35 mm equivalent). The Minolta is designed to go from 28 mm to 22.4 mm.

• The WC-DC58N is designed for compact camera, the ACW-100 for a SLR (bigger sensor size).

• Intrinsic design quality

jgardia said:

Dear William,

I think the effective f-number will be 1.3, since you are reducing the focal length, but not the aperture diameter. What do you think?

Click to expand...

No one else has answered, so I will. (I was hoping to post some more pix I'd taken with my Panasonic WA adaptor - later.) Strictly, you are not changing the focal length - the prime lens just does what it always did! ;-)

If the adaptor has enough glass to 'direct' the light into the prime lens, then the effective f no does not change. In effect it just sees a wider view. OTOH, if the adaptor has not enough glass, you will get vignetting - which in turn may affect the total amount of light transmitted.

Hope it helps!

Mike
--
Mike Davis
Photographing the public for over 50 years
http://www.flickr.com/photos/watchman

ACW-100 was made for the A1,A2,A200 Konica Minolta bridge cameras. Sensor size on those is pretty small, nowhere near APS -C size. It served me well when using it with my A200, and I'm pleased to find that I can use it with the new G1 as well. I also have an Olympus A-28 which was actually made for use with an old APS film system camera. It also has 49mm thread, and worked fine on my old Canon G2, but would vignette when attached to the Konica Minolta. I have a step-down ring on order, and will try both on the 14-45 as soon as it arrives. The Olympus lens is even smaller and lighter than the Konica Minolta so it would be the first choice if it provides corner to corner coverage.

Anyone else have one of the Olympus A-28 lenses stashed, forgotten in a closet somewhere. Pull it out and give it a try.

I am curiously awaiting your tests on the 14-45mm...Thanks
Rick
--
http://bejersey.smugmug.com/

I got quite interested in your combination of lens and wide angle adapter. I searched for Digital Concepts and got many results. Would you care to point me out the specific reference of the adapter you got?

And would be so kind to post an interior architecture shot with and without the adapter? Shot in Manual, we could make out the quality of this wide angel adapter.

Thank You!

This is the model I got:

http://www.gadgetinfinity.com/product.php?productid=16665&cat=276&page=1

Unfortunately I am not going to be able to perform the test you requested anytime soon, but hey, did you see the price? Not a big risk to test for yourself!

Hi William,

Thanks for the little 'plug'. I'm pleased to say that I'm still using my ACW-100 converter and recently took it on a trek in Nepal:









Photos straight out of the camera except downsizing/sharpening in Irfanview.

The detail in the second photo, especially in the corners, and the relatively straight lines certainly indicates that the ACW-100 does a pretty good job!

William Ing said:

For my money, pbar's suggestion re the Minolta ACW 100 wide converter in the second post is far and away the best option if you're looking to put any kind of wide converter on the 14-45 Panny zoom. The idea was first suggested many months ago by Frank Jones of Melbourne, who posted photos of the rig and sample images here:

http://forums.dpreview.com/forums/readflat.asp?forum=1041&message=31768490

Click to expand...

How usable would this be with the Olympus 9-18 mm ? It would give 8 mm lens in 35 mm terms!
Has anyone tried a wide angle adapter on a wide angle lens ?