Forgot Password
Pentax Camera Forums Home
 

Showing results 1 to 14 of 14 Search:
Forum: Pentax SLR Lens Discussion 01-17-2019, 12:46 AM  
Interesting unknown K-mount 200mm F2.8 lens: Goi-mc-telegoir
Posted By kds315
Replies: 9
Views: 1,094
Here now a few images shot in my famous park, also at f2.8 on GH4













Forum: Pentax SLR Lens Discussion 01-15-2019, 07:40 AM  
Interesting unknown K-mount 200mm F2.8 lens: Goi-mc-telegoir
Posted By kds315
Replies: 9
Views: 1,094
Weather got better, so I grabbed the Telegoir 2.8/200mm and took it to my friend's flower shop.
All shot at f2.8









Forum: Pentax SLR Lens Discussion 01-14-2019, 12:42 AM  
Interesting unknown K-mount 200mm F2.8 lens: Goi-mc-telegoir
Posted By kds315
Replies: 9
Views: 1,094
Well, yes, but I'm not here that often... ;-)

It is a great lens and a wonderful, unexpected find and so far I'm very happy with this lens..

Now I just need better weather!!!

The album I will be putting more into is here: GOI MC Telegoir f2.8 200mm | Flickr

Unfortunately there are only four (4) such GOI prototype lenses currentgly known to exist,
but my friend's lens is 10 numbers from mine, so there were a few more made...

This lens was the prototype of the later made OBERON 2.8/200mm, which uses the same
optic design but unfortunately a very badly made housing, plastics and wobbly focusing, quite a
nightmare lens from what I heard. Also optically far from that prototype. A friend has one and
he just calls it "crap".
Forum: Post Your Photos! 05-20-2014, 08:40 PM  
Nature Ultraviolet and animal vision photography
Posted By kds315
Replies: 4
Views: 729
Thanks guys!

About animal vision incl. how cats see, have a look here: How Animals See the World - Issue 11: Light - Nautilus
Forum: Post Your Photos! 05-20-2014, 12:43 AM  
Nature Ultraviolet and animal vision photography
Posted By kds315
Replies: 4
Views: 729
Well, here comes my first try showing some of my work regarding reflected ultraviolet (UV) photography as well as simulated (tetrachromatic/trichromatic) butterfly and bee vision.

Humans see blue, green and red, whereas butterflies can see UV, blue, green and red and bees see UV, blue and green only. So I developed a method to make that visible by mapping their color space into ours we can see.

This is a Apache beggarticks - Bidens ferulifolia flower as an example.

Human Vision (400-750nm):


Reflected Ultraviolet (300-400nm):


Simulated Butterfly Vision (300-700nm):


Simulated Bee Vision (300-600nm):


Quadriptych to compare:


It gets quite obvious that this Bidens flower has a prominent UV pattern, completely invisible to us humans.
Its petal tips are UV bright around 365nm, its center is quite UV dark, thus serving as a landing guide (nectar guide)
for bees which gets nicely visible also in the simulated vision images.

I won't go into the details of how to achieve this here, as it is shown in detail on my Blog (last link in my signature)
Forum: Pentax SLR Lens Discussion 05-20-2014, 12:27 AM  
Pentax Quartz UV only 85/3.5?
Posted By kds315
Replies: 13
Views: 2,958
Thanks, I'll have a look into that.
Forum: Pentax SLR Lens Discussion 05-19-2014, 11:46 PM  
Pentax Quartz UV only 85/3.5?
Posted By kds315
Replies: 13
Views: 2,958
Just in case: here is a video of a Gazania flower opening (timelapse) shot in UV:
















You Tube



Forum: Pentax SLR Lens Discussion 05-19-2014, 11:24 PM  
Pentax Quartz UV only 85/3.5?
Posted By kds315
Replies: 13
Views: 2,958
Thanks Guys! Guess I should post a bit more here about this sort of photography....
Forum: Pentax SLR Lens Discussion 05-19-2014, 02:55 AM  
Pentax Quartz UV only 85/3.5?
Posted By kds315
Replies: 13
Views: 2,958
If you had looked at my last link in my footer ("my UV diary"), you'd seen more than 500 BLOG entries, all shot with such lenses.
So in short, they do see "some use" and even companies like BBC London + Bristol and Sir David Attenborough use my work.

This is a Phalaenopsis orchid in UV shot with this lens and the Baader-U filter:


Even the cell structures of the surface gets visible, as with UV a much higher resolution can be achieved.
Forum: Pentax SLR Lens Discussion 05-18-2014, 02:51 AM  
Pentax Quartz UV only 85/3.5?
Posted By kds315
Replies: 13
Views: 2,958
Boxes with desiccant in them. Works pretty well.
Forum: Pentax Price Watch 05-17-2014, 05:20 AM  
Quartz Takumar 85/3.5
Posted By kds315
Replies: 14
Views: 5,417
Here is a pic in UV taken with teh Quartz Takumar 3.5/85mm

Forum: Pentax SLR Lens Discussion 05-17-2014, 05:19 AM  
Pentax Quartz UV only 85/3.5?
Posted By kds315
Replies: 13
Views: 2,958
Yes, I have two actually and the link is to my collection ;-)
Forum: Pentax Price Watch 05-17-2014, 05:17 AM  
Quartz Takumar 85/3.5
Posted By kds315
Replies: 14
Views: 5,417
Just in case, a shot with the quartz Takumar 3.5/85mm

UV image (300-4400nm) using Baader-U-filter
Forum: Pentax Price Watch 05-17-2014, 05:08 AM  
Quartz Takumar 85/3.5
Posted By kds315
Replies: 14
Views: 5,417
@Digitalis: Don't confuse the earlier Quartz Takumar 3.5/85mm with the later Ultra Achromatic Takumar 4.5/85mm which superseded that, two quite different lenses! (Links to my collection added)

Btw only eight (8) Quartz Takumars 3.5/85mm are known to exist, including a recent one I just found - need one?
Search took 0.00 seconds | Showing results 1 to 14 of 14

 
Forum Jump


All times are GMT -7. The time now is 10:22 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top