Jump to content

ISCO ultra star red the actual stretch factor.


Anton Zimin
 Share

Recommended Posts

Hey everybody!

Finally I've bought an ISCO adapter as the one at the picture. It works great and focuses ok. But it seems it's not 2x at all. It 's a bit less. Does anybody know the actual stretch factor? To me it's about 1.88, but I'm not sure. 

RED+LENS+WITH+CLAMP.jpg

The guy on this link says it is 1.9. To me seem it works ok.

Link to comment
Share on other sites

EOSHD Pro Color 5 for Sony cameras EOSHD Z LOG for Nikon CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs

It's probably a basic hypergonar formula. Just very well corrected and coated. Google it. 

If you have sharpness trouble, you might want to try a little bit before infinity on your taking lens. If it's not changing anything, try another taking lens. If it's not sharp, then your isco has alignment issues. Not that complicated to correct actually but still a little pain. 

Link to comment
Share on other sites

  • 3 weeks later...
20 hours ago, Zalem said:

I had this lens for a while (and regret selling it).

I used to apply 1.75x stretch in post. Definitely not a 2x lens but it produces great images nonetheless.

Cheers.

I don't think so.  Definitely a 2x lens for me to use.  Here are 3:1 pictures from 3:2 sensor camera.

spsIMG_9085.jpg

 

 

img9185.jpg

Link to comment
Share on other sites

7 hours ago, ken said:

I don't think so.  Definitely a 2x lens for me to use.  Here are 3:1 pictures from 3:2 sensor camera.

spsIMG_9085.jpg

 

 

img9185.jpg

Cool, I guess there's no one answer to this question. As mentionned above, stretch factor could vary from close focus to infinity, or perhaps some copies simply have a different stretch factor.

Definitely a sharp lens, but fyi to my surprise my Kowa 16-D has produced sharper images than the Isco. Comes with its flaws however.

Link to comment
Share on other sites

13 hours ago, Zalem said:

Cool, I guess there's no one answer to this question. As mentionned above, stretch factor could vary from close focus to infinity, or perhaps some copies simply have a different stretch factor.

Definitely a sharp lens, but fyi to my surprise my Kowa 16-D has produced sharper images than the Isco. Comes with its flaws however.

IMO, they have the same sharpness for all these size lens.   The difference is the view angle.  ISCO can use 100mm without vignetting at infinity on FF camera.  16-D needs 135mm.  

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • EOSHD Pro Color 5 for All Sony cameras
    EOSHD C-LOG and Film Profiles for All Canon DSLRs
    EOSHD Dynamic Range Enhancer for H.264/H.265
×
×
  • Create New...