本帖最後由 jojomamani 於 2010-2-6 11:26 編輯
8# carfield
That's my set up for mounting DSL camera(s) on my etx-90.
My APS sized camera is a Canon 500D with 650nm Infrared corrected
The full frame camera is a Canon 5DII for normal visible light.
The image were shoot indoor through the window without glasses in the optical path between the etx-90 & the buildings. shutter were released after 10sec. with mirror locked.
The image that took by the ext-90 & with cameras were sized down to 50% linear.
The eyepiece adaptor is good on etx-90, it yield a better balance in compare with the direct photography rear port. Also it make possibility to take photos with objects at the top of the sky.
B'cos of the position of the finder is quite close to the eyepiece outlet. it's better to use small APS camera. Pls. check the following pictures.
Note that my eyepiece is a very short one, I've been using a longer one cos' I was considering the obstruction with the smart finder, but I found the longer light travelling path cos more internal reflection that lower the contrast of the image, even I matt the internal tube with velvet paper. Plus this lens is long enough already, longer the exiting path narrow down the field of view. Not good at all. You may hv to reconsider whether you need the "variable projection camera adaptor".
If u compare the image carefully. The image with eyepiece adaptor is not as sharp as the one that took with the direct rear port. I believe it's not my focusing problem. It may be the double image cos by the thin mirror. It's a trade off with the better balance. I keep both setup as a possibility to shoot object that higher than 70°, which the direct mount to the rear port can't do.
Note the image is vertical fliped
APS frame with eyepiece adaptor
APS size frame camera
Full frame with eyepiece adaptor
Full frame 35mm frame camera, the image circle is not enough to fill up the frame.
The #64 T-adapter(it comes with 2 parts; An adaptor tube between the rear opening of etx-90 & the T-ring, also an extension tube for full frame 35mm camera) are always hv a balance issue when using it, the weak fiction of the mount is not that good on holding it! expecially using both parts with the full frame camera. Pls. check the image.
Set up with short #64 T-adaptor tube, the focal length is 1250mm f/13.8
APS frame with short tube only
APS size frame camera with basic #64 T-adaptor
full frame with short tube only
Full frame 35mm size camera with basic #64 T-adaptor, again the image circle is not able to fill up the whole frame.
Set up with both #64 T-adaptor tubes, the focal length will be longer up to 1450mm f/16
APS frame with both tubes
APS size frame camera with both #64 T-adaptor
full frame with both tubes
Full frame 35mm size camera with full #64 T-adaptor, That's the only set up able to shoot full frame 35mm. but the weight & the unbalanced torque/moment make the whole setup very difficult to operate. Not recommended! |