Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax / Samsung dSLR, K Mount Mirrorless

Reply
 
Thread Tools Search this Thread
Old Dec 30, 2009, 6:41 PM   #1
Member
 
Join Date: Jun 2006
Location: South-Eastern Minnesota
Posts: 40
Default A Macro Question

The Sigma Specs. state a Minimum Focusing Distance of 7.4 inches for my 50mm EX DG f/2.8 Macro but when I go to the 1:1 setting I am literally on top of my subject (I'm guessing here about 1 inch from front of lens to my subject). It's a beautiful piece of workmanship and I get some fantastic pictures, But, most things that eat and breath won't let me get that close for a silly picture. I am thinking of getting rid of this lens and getting one with a bit more breathing room. If I can't go by Sigma's stated Minimum focusing distance then what do I go by for the distance tween the lens and subject ?? I love Macro shooting but this has kept me from really getting into it as much as I would like. I see where most of ya'll use a 105mm Macro lens and the pictures are fantastic. Here is 1 example where I should have asked HERE first b4 I went out and bought my Sigma 50mm EX DG 2.8 Macro lens in June of 2008. Any help would be appreciated. Thanks all.
AZK6er is offline   Reply With Quote
Sponsored Links
Old Dec 30, 2009, 7:27 PM   #2
Senior Member
 
mtngal's Avatar
 
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,056
Default

Yes, the 50 mm is a good lens if you want to get really close to your subject. Not good with bugs. It more or less works that the longer the lens, the more distance you can have between yourself and your subject (assuming that the lens can do 1:1). Macro lenses around 100 mm are common and all seem to be very sharp. A 180 or 200 macro would allow you to stand off even further, but I'm not sure there's anyone still making one in Pentax mount. Pentax made both an A* and an FA* in 200 mm, but finding one at a somewhat reasonable price is difficult. Sigma makes a 180 macro in Pentax mount, that would let you stand back even more than the 100 mm ones would.

Auto focus isn't always a good idea when shooting macro - I had an inexpensive AF lens and used it almost exclusively with manual focus. When I decided to upgrade to a better one, I got a manual focus lens - the Vivitar Series One 105 macro. Quite a few of us have picked up this lens (it's no longer being made). If I had had the money, I would have bought a Voitlander macro but it was a lot more and I don't believe it's in production any more now (it was when I was looking).

The Tamron 90 mm macro always seems to give good results, at least from what I've seen posted here and elsewhere. The Sigma and Pentax are only slightly behind it. Then there's the Zeiss 100 mm macro - if you'll give me the winning lottery numbers I would be happy to buy one and test it for you. It only costs $1788 at the moment and while I'd love to own a Zeiss lens, I've never looked at anyone's sample shots to see if it's worth that much more than the $250 I spent on my Viv.
mtngal is offline   Reply With Quote
Old Dec 30, 2009, 8:39 PM   #3
Member
 
Join Date: Jun 2006
Location: South-Eastern Minnesota
Posts: 40
Default

Thanks mntgal,
You said "A 180 or 200 macro would allow you to stand off even further". How much distance are you talking about "to stand off" with a 105mm anyways, 5 inches, 10 inches ? I don't even mess around with the focus (manual or AF). With my 50mm Sigma set to 1:1 I just move the whole contraption (Tri-pod and all) forward or backwards as needed to focus as I'm so darn close anyways. Oh BTW, I shoot in Manual Exposure when TRYING to do Macro.

Last edited by AZK6er; Dec 30, 2009 at 8:42 PM.
AZK6er is offline   Reply With Quote
Old Dec 30, 2009, 9:15 PM   #4
Senior Member
 
Join Date: Mar 2007
Posts: 520
Default

I'd probably throw in a vote for the Tamron 90mm f/2.8 which has a minimum focusing distance of 11.4 inches.

Sigma has a 180mm Macro lens that's pretty nice as well. Although, I don't have one.




Last edited by EddyinGA; Dec 30, 2009 at 9:18 PM.
EddyinGA is offline   Reply With Quote
Old Dec 30, 2009, 9:20 PM   #5
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,571
Default

The minimum focusing distance is from the subject to the focal plane. That's why the camera body has that focal plane indicator on the top.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.

Last edited by TCav; Dec 30, 2009 at 9:29 PM.
TCav is offline   Reply With Quote
Old Dec 31, 2009, 12:54 AM   #6
Member
 
Join Date: Jun 2006
Location: South-Eastern Minnesota
Posts: 40
Default

Thanks EddyinGA for the pic's, now thats what I'm talkin about, is that a spider in there ?
TCav "That's why the camera body has that focal plane indicator on the top." I'm about to learn something new. I have a K100 Super but don't see any indicator on it, please explain further if you would ?
AZK6er is offline   Reply With Quote
Old Dec 31, 2009, 9:38 AM   #7
Senior Member
 
Join Date: Mar 2007
Posts: 520
Default

Quote:
Originally Posted by TCav View Post
The minimum focusing distance is from the subject to the focal plane. That's why the camera body has that focal plane indicator on the top.
I just looked at the top of my K20D. A focal plane indicator??? News to me.
EddyinGA is offline   Reply With Quote
Old Dec 31, 2009, 10:09 AM   #8
Member
 
jennlynn130's Avatar
 
Join Date: Nov 2009
Posts: 53
Default

What is the difference between a macro lens and a regular lens of the same mm?
jennlynn130 is offline   Reply With Quote
Old Dec 31, 2009, 10:34 AM   #9
Senior Member
 
shoturtle's Avatar
 
Join Date: Dec 2009
Location: Frankfurt AM
Posts: 11,348
Default

Marco lenses allow you to focus in on something very close, on some 50mm marco lens, you can have the subject as close as 1.2ft away and the lens can still focus on it. A non marco lens will not be able to focus on something that close.

Last edited by shoturtle; Dec 31, 2009 at 10:43 AM.
shoturtle is offline   Reply With Quote
Old Dec 31, 2009, 10:43 AM   #10
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,571
Default

Quote:
Originally Posted by AZK6er View Post
I have a K100 Super but don't see any indicator on it, please explain further if you would ?
I've been trying to get onto the Pentax website, trying to confirm that Pentax actually does put a focal plane indicator on their dSLR bodies, but I've been getting error messages each time. From your response, I guess they don't.

The mimimum focus distance for any lens is from the subject to the image sensor, not to the front of the lens. It usually doesn't matter much until you try to use a macro lens. That's why some dSLRs have a focal plane indicator on the camera body. It's a small circle with a horozontal line through it. The horizontal line is where the focal plane is, so you can measure the distance from the subject to the focal plane and set the focus manually. That's why, when using the Sigma 50/2.8 macro lens, the subject is within an inch or two of the front of the lens. The minimum focusing distance of that lens is 7.4 inches, but the lens is 2.6 inches long. That plus the depth of the camera body only leaves a couple of inches between the subject and the front of the lens.

Since your body doesn't have a focal plane indicator, you must guess where the focal plane actually is if you want to focus manually. (I mean REALLY manually. Like with a ruler and the distance scale on the lens.)
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.

Last edited by TCav; Dec 31, 2009 at 10:45 AM.
TCav 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 9:42 AM.