cwchan

Special thanks to Mandy who gives her GH1 and 20mm f1.7 pancake lens for my digiscopic testing.

All the test shots here were taken on 10.12.2009 at Mai Po.
A very hazy day

The setting
ISO 100,
Taken in RAW, converted to TIFF and then to JPG by using Silkypix (recommended by Panasonic) and Photoshop respectively.
Using the original electric shutter cable release to reduce human vibration.
A-mode (aperture priority)
Lens ( the pancake 20mm f1.7) setting at its f2.8 for all the shots.

Pros
Fast and able to get precise automatic focus with my 30X scope.
Light weight ( about the same weight of my old Nikon 8400).
Bright electric view finder. It brightens automatically at dim situation.
High-eye points, very usefully for spectacle wearers as we need not to come too close to (to touch) the view finder which may cause vibration.
The shutter vibration is not so obvious (most probably due to the presence of the long-plate to support the system).

Cons
Noticeable shutter release time lap.
The 20mm lens is not so sharp as expected.

Suggestion for improvement of the lens in field usage
The focusing design of the 20mm f1.7 lens is a front glass moving. My DCA has to be connected to the front ring of that focus lens directly. When the lens goes to get for focus, it goes in and out. That means, when the camera is placed on the scope via the DCA, the automatic focusing mechanism (inside the lens) carries the whole weight of the GH-1 and the lens while focusing. It will certainly slow down the automatic focus movement and, in some degree of extent, overstress the focusing gears inside, eventually causing rapid wear and tear of the lens.

If a coupling ring is made with one end connecting the DCA directly and the other end to the barrel of the lens as per photo No.3 (the green sketch), it functions like an internal focus lens, the weight is transferred via that coupling ring to the DCA without affecting the movement of the focusing mechanism, then the problem mentioned above will be solved.


No.1 The setup


No.2


No.3


No.4 At the far away side of Bird hide No.9


No.5


No.6


No.7


No.8


No.9  The original uncropped image


No.10  The 100% cropping of No.8 above


[ Last edited by cwchan at 11/12/2009 18:26 ]

cwchan

Its big image sensor always has its advantage that the small dc could not give you the detail like the photo below.

cwchan

I am happy to try out this gear again after having installed with the 52mm adaptor ring. With this adaptor ring in place , it solved the problem mentioned above.
I can take the photo with  my eye  touching the EVF and get the  focus automatically controlled by the dc itself, which is just similar to common dslr .



The following sample photos were taken on January 4, 2010 at Mai Po, boardwalk.
Setting at ISO100, A-mode, f4, EV compensation to -2EV (After trial and error, I get this value for the right exposure, I don't know the reason why?)





The original uncropped image


Portion of above shot (about 95%)


[ Last edited by cwchan at 6/01/2010 08:31 ]

cwchan

There is not much space for mounting the adapter ring, the space is about 3mm only, therefore the ring must be very good fit.
I don't think it is necessary for making this kind of ring for its (Lumis) standard zoom lens as this zoom lens is already internal focus type, it does not move externally while focusing.

Ricoh GRX 24-72 (S10 module)'s CCD is only 1/1.7 while Nikon 8400 is 1/1.5, 8400 equipped with the biggest ccd ever make in the dc market.
The 10 mega ccd being used in Ricoh should be better than 8400 in terms of noise and detail.
I have reservation on the optical quality of this Ricoh lens, the ED lens for the 8400 is really super indeed.

cwchan

It is a custom-made adaptor specially requested by a friend.
I don't recommend this adaptor to be installed by the user himself due to the technical difficulty.

[ Last edited by cwchan at 6/01/2010 20:38 ]