Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and our Privacy Policy.
OK
Index  •   • New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Guest
New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Register to forums    Log in

 
FORUMS Photography Talk by Genre General Photography Talk 
Thread started 24 Jul 2011 (Sunday) 15:21
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

PSA: Leave MFA alone unless you know exactly what you are doing.

 
supergoat
Member
Avatar
181 posts
Joined Dec 2005
Location: Columbia, SC
     
Jul 24, 2011 15:21 |  #1

EDIT
PSA: Public Service Announcement
MFA: Microfocus Adjustment

(Thanks SkipD :))

My story...

So I am on my second copy of a Sigma 24-70/2.8 EX HSM and just filled out the form to send this one off to be calibrated for front focusing issues. This one seemed to be much closer, my first copy....there was no hope for.

I could not get it to focus correctly. I recently made a thread asking about if the price difference between the 7D and 60D is worth it. Bottom line, my mind was made up to get the 7D until I got a deal on a 50D that I would have been stupid to turn down. I am still going to get a 7D in the near future but this 50D will satisfy my urge for a while longer.

Anyway that is not the point, the point it I thought the Sigma was front focusing so bad that even setting the 50D's MFA at +20 didn't cure it. After days of messing around I was ready to send this one off until I said to myself, "Self, why not just go take some real world shots at F2.8 instead of the hundreds of shots I've taken of focus sheets and close up stuff in my apartment?"

So I leave the MFA at +20 and go outside. All of my shots are backfocused like crazy! So I set the MFA at 0, head back outside and all of a sudden my F2.8 shots are spot on. They are tack sharp right where I was focusing.

So moral of the story, I learned that not only do I not know how to properly use a focusing sheet but shooting objects that are about only a foot away from the lens isn't the best way to gauge how well the autofocus is working. I cancelled the repair.

So unless you know 100% what the hell you are doing leave MFA alone!

:D


Canon 50D | 430exII Speedlite
Canon 50mm 1.8, Sigma 24-70 F2.8 EX HSM

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
SkipD
Cream of the Crop
Avatar
20,476 posts
Likes: 154
Joined Dec 2002
Location: Southeastern WI, USA
     
Jul 24, 2011 15:44 |  #2

supergoat wrote in post #12814592 (external link)
PSA: Leave MFA alone unless you know exactly what you are doing.

supergoat wrote in post #12814592 (external link)
....the point it I thought the Sigma was front focusing so bad that even setting the 50D's MFA at +20 didn't cure it. After days of messing around I was ready to send this one off until I said to myself, "Self, why not just go take some real world shots at F2.8 instead of the hundreds of shots I've taken of focus sheets and close up stuff in my apartment?"

What the heck are the abbreviations "PSA" and "MFA" supposed to mean? It might be a good idea to either avoid using weird abbreviations or at least to define them in your post.

The 50D function I think you are talking about is AF Microadjustment which would be abbreviated AFM if it needed to be abbreviated. ;)


Skip Douglas
A few cameras and over 50 years behind them .....
..... but still learning all the time.

  
  LOG IN TO REPLY
supergoat
THREAD ­ STARTER
Member
Avatar
181 posts
Joined Dec 2005
Location: Columbia, SC
     
Jul 24, 2011 16:12 |  #3

PSA = Public Service Announcement.
MFA would be the adjustment you are talking about. When researching it I found it called MFA or "Micro Focus Adjustment".

I figued a Camera forum would know MFA and anyone who was 8 and went to grade school would know PSA...at least in SC we had to watch enough of them. :D


Canon 50D | 430exII Speedlite
Canon 50mm 1.8, Sigma 24-70 F2.8 EX HSM

  
  LOG IN TO REPLY
tkerr
Goldmember
Avatar
3,042 posts
Likes: 2
Joined Mar 2010
Location: Hubert, North Carolina, USA.
     
Jul 24, 2011 16:26 |  #4

supergoat wrote in post #12814592 (external link)
EDIT
PSA: Public Service Announcement
MFA: Microfocus Adjustment

(Thanks SkipD :))


So moral of the story, I learned that not only do I not know how to properly use a focusing sheet but shooting objects that are about only a foot away from the lens isn't the best way to gauge how well the autofocus is working. I cancelled the repair.

So unless you know 100% what the hell you are doing leave MFA alone!

:D

No it's not, There is a minimum distance depending on the focal length of your lens.

http://www.northlight-images.co.uk …s3_af_micoadjus​tment.html (external link)
"Camera-to-subject distance should be no less than 50 times the focal length of the lens. For a 50mm lens, that would be at least 2.5 meters."


Tim Kerr
Money Talks, But all I hear mine saying is, Goodbye!
F1, try it you'll like it.

  
  LOG IN TO REPLY
HappySnapper90
Cream of the Crop
5,145 posts
Likes: 3
Joined Aug 2008
Location: Cleveland, Ohio
     
Jul 24, 2011 16:38 |  #5

SkipD wrote in post #12814679 (external link)
What the heck are the abbreviations "PSA" and "MFA" supposed to mean? It might be a good idea to either avoid using weird abbreviations or at least to define them in your post.

You have over 16,000 posts over 9 years on this forum. You should know what they mean by now. And the term PSA is also used in the media.




  
  LOG IN TO REPLY
SkipD
Cream of the Crop
Avatar
20,476 posts
Likes: 154
Joined Dec 2002
Location: Southeastern WI, USA
     
Jul 24, 2011 17:00 |  #6

HappySnapper90 wrote in post #12814898 (external link)
You have over 16,000 posts over 9 years on this forum. You should know what they mean by now. And the term PSA is also used in the media.

My comments were really written to help make the first post in the thread understandable by newbies reading the forums. Abbreviations can easily confuse the newbies when there are over 50 definitions on the web for the same abbreviation.


Skip Douglas
A few cameras and over 50 years behind them .....
..... but still learning all the time.

  
  LOG IN TO REPLY
supergoat
THREAD ­ STARTER
Member
Avatar
181 posts
Joined Dec 2005
Location: Columbia, SC
     
Jul 24, 2011 17:16 |  #7

HAHA, wow. This thread took a turn... :)


Canon 50D | 430exII Speedlite
Canon 50mm 1.8, Sigma 24-70 F2.8 EX HSM

  
  LOG IN TO REPLY
supergoat
THREAD ­ STARTER
Member
Avatar
181 posts
Joined Dec 2005
Location: Columbia, SC
     
Jul 24, 2011 17:16 |  #8

tkerr wrote in post #12814821 (external link)
No it's not, There is a minimum distance depending on the focal length of your lens.

http://www.northlight-images.co.uk …s3_af_micoadjus​tment.html (external link)
"Camera-to-subject distance should be no less than 50 times the focal length of the lens. For a 50mm lens, that would be at least 2.5 meters."

Thanks, I just learned something. It shows that even if you have been doing something for years you can still learn something that's considered basic. :)


Canon 50D | 430exII Speedlite
Canon 50mm 1.8, Sigma 24-70 F2.8 EX HSM

  
  LOG IN TO REPLY
rick_reno
Cream of the Crop
44,642 posts
Likes: 131
Joined Dec 2010
     
Jul 24, 2011 18:01 |  #9

I didn't know what PSA was, I looked at my keyboard to see how close the "T" key was to the "P" thinking it was another TSA rant.




  
  LOG IN TO REPLY
Tony-S
Cream of the Crop
Avatar
9,903 posts
Likes: 200
Joined Jan 2006
Location: Fort Collins, Colorado, USA
     
Jul 25, 2011 13:39 |  #10

rick_reno wrote in post #12815223 (external link)
I didn't know what PSA was...

For most of us, it's Photographic Society of America. For us older guys, it's prostate specific antigen...


"Raw" is not an acronym, abbreviation, nor a proper noun; thus, it should not be in capital letters.

  
  LOG IN TO REPLY
Rocky ­ Rhode
Goldmember
Avatar
1,416 posts
Likes: 6
Joined Apr 2011
Location: Sacramento
     
Jul 25, 2011 14:15 |  #11

When it comes to the use of acronyms all I can think of is BFD


GEAR LIST Flickr (external link)

  
  LOG IN TO REPLY
MilesW
Member
240 posts
Likes: 2
Joined Apr 2005
     
Jul 26, 2011 05:51 |  #12

Tony-S wrote in post #12819668 (external link)
For most of us, it's Photographic Society of America. For us older guys, it's prostate specific antigen...

A familiar term for us old guys


20D Canon EFS 17-85IS, 70-2001:4 L IS, Macro 100 F2.8, Canon 50 1.4Canon ext EF 1.4X II

  
  LOG IN TO REPLY
kfreels
Goldmember
Avatar
4,297 posts
Likes: 6
Joined Aug 2010
Location: Princeton, IN
     
Jul 26, 2011 15:18 as a reply to  @ MilesW's post |  #13

Well, I understood both acronyms.


I am serious....and don't call me Shirley.
Canon 7D and a bunch of other stuff

  
  LOG IN TO REPLY
JOSX2
Senior Member
627 posts
Likes: 3
Joined Jan 2011
Location: Mebane, NC (meh-ben)
     
Jul 26, 2011 15:57 |  #14

SkipD wrote in post #12814975 (external link)
My comments were really written to help make the first post in the thread understandable by newbies reading the forums. Abbreviations can easily confuse the newbies when there are over 50 definitions on the web for the same abbreviation.

well then why not simply have said in your first post:
To the newbies reading this...PSA means yada yada...MFA means yada yada yada.

rather than asking the question that you did.


website: Jim O'Sullivan Photography (external link) | Facebook (external link)
The Camera:  |- Gripped 60D  -|- EF-S 50mm f/1.8 II -|- Canon 24-70mm f/4 -|- Canon 70-200 f/4 -|
Speedlights:   |- 3 Yongnou YN600EX-RT Speedlights -|- YN-E3-RT Transmitter -|
Studio Strobes:  |- Alien Bee B800 & B1600 -|- CyberSync Wireless system -|

  
  LOG IN TO REPLY
SkipD
Cream of the Crop
Avatar
20,476 posts
Likes: 154
Joined Dec 2002
Location: Southeastern WI, USA
     
Jul 26, 2011 16:38 |  #15

JOSX2 wrote in post #12827068 (external link)
well then why not simply have said in your first post:
To the newbies reading this...PSA means yada yada...MFA means yada yada yada.

Quite frankly, I did NOT understand what the poster meant by the abbreviations - particularly the "PSA" which is a medical blood test to me - without some research.

My goal is to suggest that folks make posts that are understandable by all, including the newbies. Thus, I sometimes recommend that folks not use weird abbreviations and assume that everybody will understand them.


Skip Douglas
A few cameras and over 50 years behind them .....
..... but still learning all the time.

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)

2,241 views & 0 likes for this thread
PSA: Leave MFA alone unless you know exactly what you are doing.
FORUMS Photography Talk by Genre General Photography Talk 
AAA
x 1600
y 1600

Jump to forum...   •  Rules   •  Index   •  New posts   •  RTAT   •  'Best of'   •  Gallery   •  Gear   •  Reviews   •  Member list   •  Polls   •  Image rules   •  Search   •  Password reset

Not a member yet?
Register to forums
Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!


COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and to our privacy policy.
Privacy policy and cookie usage info.


POWERED BY AMASS forum software 2.1forum software
version 2.1 /
code and design
by Pekka Saarinen ©
for photography-on-the.net

Latest registered member is Dman780
997 guests, 336 members online
Simultaneous users record so far is 15144, that happened on Nov 22, 2018

Photography-on-the.net Digital Photography Forums is the website for photographers and all who love great photos, camera and post processing techniques, gear talk, discussion and sharing. Professionals, hobbyists, newbies and those who don't even own a camera -- all are welcome regardless of skill, favourite brand, gear, gender or age. Registering and usage is free.