67 replies to this topic

[chile]

i use the 7.5mm Samyang FE MFT on my E-PL1 and it takes some pretty decent shots in the precision dome port for the panny 8mm. apples and oranges, i know, but learning to work the samyang has made me less "needy" to get the AF panny 8mm FE.

[Scubysnaps]

i use the 7.5mm Samyang FE MFT on my E-PL1 and it takes some pretty decent shots in the precision dome port for the panny 8mm. apples and oranges, i know, but learning to work the samyang has made me less "needy" to get the AF panny 8mm FE.

Thanks Chile

[Scubysnaps]

I've just been to a tourist aquarium in my local city and while the lights were down somewhat causing me to use a hi iso and with their thick scratched concave glass, I feel it gives me some more confidence in the lens for underwater use

[coroander]

Minimum focus on the Micro Four Thirds Samyang 7.5mm fisheye is 0.09m which allows it to focus easily on the virtual image which extends from 0.10 to 0.20m in the Nauticam 4.33" dome.

[chile]

here's recent example (cropped and some light LR work...i don't know more than the presets). lens set to F11-0.5ft....tried that same setting on a pretty big sea fan (second pic) and need to go back with it set to 0.8ft i think

[Scubysnaps]

I reserve to have faith in my spanking new lens, despite coroanders numbers, if he has a diagram to let us understand better it may make some sense, but really think its just baffling the brain with science which isnt proven

[coroander]

You'll find everything you need to do the calcs on this site, here:
http://wetpixel.com/...ll/dome-theory/

Also, one can simply check the focus distance in the EXIF data for those using the Nauticam 4.33" dome port. It will vary from system to system, with DSLRs showing greater focus distances, due to the greater distance from the entrance pupil to the sensor plane (one of the advantages of mirrorless systems is that this distance is reduced making for much thinner bodies and simpler wide-angle lens design (which tends to further decrease this distance). For Micro Four Thirds a check of the EXIF data with the Panasonic 8mm fisheye shows focus distance from 0.115m (nearly touching dome) to 0.215m (infinity).

Edited by coroander, 04 November 2012 - 04:02 PM.

[Scubysnaps]

Hi, me again

I found this little thread on the same subject over on Scubaboard, seems its ok at 0.3m min

http://www.scubaboar...mm-fisheye.html