Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Nov 20, 2007, 1:59 PM   #1
Senior Member
 
mtngal's Avatar
 
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,052
Default

I have a 100mm macro lens that does 1:1. My situation is that I want to increase the size sometimes (increase magnification), but don't want to get any closer than the normal macro lens focus distance (reason for not using an extension tube or a dioper lens, which both allow you to get larger by getting closer, which I don't want to do). I was thinking of getting a rear element teleconverter, but wondered if it would change the minimum focus distance in some way. Do they? The only one I played with was lousy and I only played with it for it's long distance capability, never for macro.

Thanks for any information.
mtngal is offline   Reply With Quote
Sponsored Links
Old Nov 20, 2007, 9:18 PM   #2
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

I just tried it with my KM5D, Minolta 70-210mm f/4 Macro ('Beercan') and a Quantaray 2X DG TC. As far as I could tell, the minimum focus distance was about the same, with or without the TC.
TCav is offline   Reply With Quote
Old Nov 20, 2007, 10:13 PM   #3
Senior Member
 
mtngal's Avatar
 
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,052
Default

Thanks for the information - looks like I'll start looking for something along the lines of a 1.7 TC. Get it for the macro application but play with it for birding? Not such a bad idea at that.
mtngal is offline   Reply With Quote
Old Nov 20, 2007, 10:16 PM   #4
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

Didn't you once mention that you had a TC that you took the optics out of so you could use it as an extention tube?

In addition to doubling the focal length, my Quantaray 2X TC adds gobs of CA. Keep that in mind when you go shopping.
TCav is offline   Reply With Quote
Old Nov 21, 2007, 8:03 AM   #5
Senior Member
 
mtngal's Avatar
 
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,052
Default

Yes - the TC I had was a very poor one (had originally been bought by my father sometime in the 1980's I think). I played around a bit with it when I got my first dSLR but the image degradation (softness mostly) was so bad I gave up trying to use it. When I decided it was useless as a TC, I tried to remove the screws holding the optics, but couldn't break them loose. Since I wasn't keeping the glass anyway, I took a chisel to it - instant extension tube. More useful but not quite what I want for a couple of things, hence the thought about getting a better TC.
mtngal is offline   Reply With Quote
Old Nov 22, 2007, 6:57 AM   #6
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

mtngal wrote:
Quote:
Since I wasn't keeping the glass anyway, I took a chisel to it - instant extension tube.
A CHISEL!!!

I wish I could have seen that! :-)
TCav is offline   Reply With Quote
Old Nov 26, 2007, 10:31 AM   #7
Senior Member
 
mtngal's Avatar
 
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,052
Default

It gave me a respect for just how hard lens glass really is - it was harder to break than I had thought, and in the end I managed to get the metal framework holding the glass elements out. It never had electronic contacts, but it does have the lever so the camera can stop down the lens. As long as the lens has some type of aperture ring it will work as a manual lens (my first attempts at macro were with this anda 50mm 1.7 manual lens).
mtngal is offline   Reply With Quote
Old Nov 26, 2007, 8:08 PM   #8
Senior Member
 
Calicajun's Avatar
 
Join Date: Jun 2007
Location: Quartz Hill, CA
Posts: 3,455
Default

TCav wrote:
Quote:
mtngal wrote:
Quote:
Since I wasn't keeping the glass anyway, I took a chisel to it - instant extension tube.
A CHISEL!!!

I wish I could have seen that! :-)
I agree that would have been fun to see.
Calicajun is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 12:37 PM.