Author Topic: February 2020  (Read 45555 times)

Jack Dahlgren

  • NG Member
  • *
  • Posts: 1528
  • You ARE NikonGear
Re: February 2020
« Reply #270 on: February 21, 2020, 23:16:54 »
Jack, lots of triangles in that - nice - image.
Fons, a tribute to your father. Nice.
Paco and John, I prefer dogs way above cats but those images are lovely.

Thanks Luc, I'm swimming in triangles...

Birna Rørslett

  • Global Moderator
  • **
  • Posts: 5185
  • A lesser fierce bear of the North
Re: February 2020
« Reply #271 on: February 22, 2020, 00:09:07 »
Akira asked for more information on my modified OM 28/3.5 lens for my Nikons. Here it is. The lens will focus from infinity down to almost the front element. Shown here with a rear filter box harbouring a Baader U2 Venus filter inside, i.e. set up for UV.

Akira

  • Homo jezoensis
  • NG Supporter
  • **
  • Posts: 12468
  • Tokyo, Japan
Re: February 2020
« Reply #272 on: February 22, 2020, 04:17:19 »
Thanks Luc, I'm swimming in triangles...

Jack, I'm enjoying your interpretation of the construction site!  Thank you for sharing!


Akira asked for more information on my modified OM 28/3.5 lens for my Nikons. Here it is. The lens will focus from infinity down to almost the front element. Shown here with a rear filter box harbouring a Baader U2 Venus filter inside, i.e. set up for UV.

Birna, thank you for the disclosure.  That is not far from what I imagined, maybe except for the filter holder.  So, the Zuiko 28/3.5 can be used for UV.
"The eye is blind if the mind is absent." - Confucius

"Limitation is inspiration." - Akira

Birna Rørslett

  • Global Moderator
  • **
  • Posts: 5185
  • A lesser fierce bear of the North
Re: February 2020
« Reply #273 on: February 22, 2020, 07:44:27 »
Rear filtration is a fringe benefit of the Z system, made possible by the very short register distance (16mm). This is useful in particular for UV where the filter options are thin on the ground and tend to be very expensive for larger sizes, if they even exist (often, not at all). Besides, the very efficient Baader U filter is dichroic and that spells problems with a wide-angle lens. In such case, for an optical design with a small exit pupil like the OM 28, rear filtration is much better.

The filter box can be replaced with an ordinary FTZ adapter if "normal" visible light photography is intended. Then, as the OM 28 lens is "chipped", all lens information can be seen and recorded in EXIF. The OM 28 does UV, but only the upper UV(A) band. Suffices for floral studies and landscapes at least.

Akira

  • Homo jezoensis
  • NG Supporter
  • **
  • Posts: 12468
  • Tokyo, Japan
Re: February 2020
« Reply #274 on: February 22, 2020, 08:17:24 »
Rear filtration is a fringe benefit of the Z system, made possible by the very short register distance (16mm). This is useful in particular for UV where the filter options are thin on the ground and tend to be very expensive for larger sizes, if they even exist (often, not at all). Besides, the very efficient Baader U filter is dichroic and that spells problems with a wide-angle lens. In such case, for an optical design with a small exit pupil like the OM 28, rear filtration is much better.

The filter box can be replaced with an ordinary FTZ adapter if "normal" visible light photography is intended. Then, as the OM 28 lens is "chipped", all lens information can be seen and recorded in EXIF. The OM 28 does UV, but only the upper UV(A) band. Suffices for floral studies and landscapes at least.

I remember the discussion on that filter system between you and Klaus quite well.  Here in Japan, Koeisha makes a nice system for the similar usage:

http://www.koheisha.net/sony/Bayonet/Bayonet_mount01.html

Exchanging filters are not as easy or quick as your system, but it seems to be well designed.  The unit can accept either an M48 or an M52 filter.
"The eye is blind if the mind is absent." - Confucius

"Limitation is inspiration." - Akira

ColinM

  • NG Member
  • *
  • Posts: 1789
  • Herefordshire, UK
    • My Pictures
Re: February 2020
« Reply #275 on: February 22, 2020, 08:22:52 »
Have any of you in Western Europe had a bit of rain in the last week?

A few rivers near me in the UK have decided to go explore the surrounding landscape - not much fun if you live there.
This is the town of Upton on Severn, taken from the top of the Malvern Hills D500 300mm


Frank Fremerey

  • engineering art
  • NG Supporter
  • **
  • Posts: 12334
  • Bonn, Germany
Re: February 2020
« Reply #276 on: February 22, 2020, 09:36:44 »
Akira asked for more information on my modified OM 28/3.5 lens for my Nikons. Here it is. The lens will focus from infinity down to almost the front element. Shown here with a rear filter box harbouring a Baader U2 Venus filter inside, i.e. set up for UV.

a lens pouch as bellows
You are out there. You and your camera. You can shoot or not shoot as you please. Discover the world, Your world. Show it to us. Or we might never see it.

Me: https://youpic.com/photographer/frankfremerey/

Thomas Stellwag

  • NG Supporter
  • **
  • Posts: 1112
Re: February 2020
« Reply #277 on: February 22, 2020, 10:52:56 »
a lens pouch as bellows

in the old inline diesel injections from BOSCH deere skin was used as membrane for the regulation. Its spec did not variy much over temperature and it was fluid/gasoil resistant
Guessing that skin specs in an animal group are not too different,  I propose moose skin as an appropriate bellows material for Nordic people, even I see the problem to find a moose with Nikon branding
Thomas Stellwag

Luc

  • NG Supporter
  • **
  • Posts: 1132
  • You ARE NikonGear
    • Flickr
Re: February 2020
« Reply #278 on: February 22, 2020, 13:00:38 »
Thomas, at least there is Nikon ambassador Moose Peterson ;)

Frank Fremerey

  • engineering art
  • NG Supporter
  • **
  • Posts: 12334
  • Bonn, Germany
Re: February 2020
« Reply #279 on: February 22, 2020, 13:55:19 »
lunch with family
You are out there. You and your camera. You can shoot or not shoot as you please. Discover the world, Your world. Show it to us. Or we might never see it.

Me: https://youpic.com/photographer/frankfremerey/

John Geerts

  • NG Supporter
  • **
  • Posts: 9120
  • Photojournalist in Tilburg, Netherlands
    • Tilburgers
Re: February 2020
« Reply #280 on: February 22, 2020, 17:36:33 »
Start of the (bank) holiday


Fons Baerken

  • NG Supporter
  • **
  • Posts: 10579
    • https://www.flickr.com/photos/fonsbaerken/
Re: February 2020
« Reply #281 on: February 22, 2020, 20:19:06 »
Thank you Luc, Jack

Fons Baerken

  • NG Supporter
  • **
  • Posts: 10579
    • https://www.flickr.com/photos/fonsbaerken/
Re: February 2020
« Reply #282 on: February 22, 2020, 20:20:26 »
February 22

charging



Z6 -- 85mm f/1.8S

Birna Rørslett

  • Global Moderator
  • **
  • Posts: 5185
  • A lesser fierce bear of the North
Re: February 2020
« Reply #283 on: February 23, 2020, 12:03:26 »
The Standout

Akira

  • Homo jezoensis
  • NG Supporter
  • **
  • Posts: 12468
  • Tokyo, Japan
Re: February 2020
« Reply #284 on: February 23, 2020, 13:12:21 »
The Standout

It would be willing to serve as the focus target for the lens test.  :D
"The eye is blind if the mind is absent." - Confucius

"Limitation is inspiration." - Akira