Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-19-2016, 08:03 AM   #1
Senior Member




Join Date: Jan 2016
Posts: 240
How to use 100mm Macro?

Hi,

I just got one of these 100mm FA macro lenses:

SMC Pentax-FA 100mm F3.5 Macro Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database

and I was wondering if there's anything special that needs to be done to use it as a "macro" lens? Can I just use it like a normal auto-focus lens, including as a macro? Or, can I only use it as a macro using manual focusing?

The reason I'm asking is that this is the first auto-focus lens I have that is a "macro" lens.

Thanks,
Jim

02-19-2016, 08:16 AM   #2
Pentaxian
LeDave's Avatar

Join Date: Jun 2009
Location: Minneapolis - St. Paul
Photos: Gallery
Posts: 2,904
Shoot at f11 or higher.
02-19-2016, 08:17 AM   #3
Site Supporter
enoeske's Avatar

Join Date: Jul 2009
Location: Surprise, Az
Photos: Gallery
Posts: 1,925
QuoteOriginally posted by ohaya Quote
Hi,

I just got one of these 100mm FA macro lenses:

SMC Pentax-FA 100mm F3.5 Macro Reviews - FA Prime Lenses - Pentax Lens Reviews & Lens Database

and I was wondering if there's anything special that needs to be done to use it as a "macro" lens? Can I just use it like a normal auto-focus lens, including as a macro? Or, can I only use it as a macro using manual focusing?

The reason I'm asking is that this is the first auto-focus lens I have that is a "macro" lens.

Thanks,
Jim
You can use it just like a normal lens, but you can get a lot closer to a subject. Very close. So close, that auto focus actually becomes a problem. So, if you want to do macro, just get in really close, get the focus somewhere near your subject, and when you're comfortable, switch to manual focus. Then use your body to slightly move forwards and backwards to get the focus to land where you want.
02-19-2016, 08:18 AM   #4
Pentaxian
bertwert's Avatar

Join Date: Jun 2015
Location: Golden, BC
Photos: Albums
Posts: 5,481
You can use it like any other AF lens you have.
Make sure you set the aperture ring to 'A' and you're all set!
It just will focus closer than other lenses you have.

Have fun!

02-19-2016, 08:24 AM   #5
Senior Member




Join Date: Jan 2016
Posts: 240
Original Poster
Hi,

Thanks. So is it correct that I should be able to focus this lens as closely if I do it automatically as if I were to do it manually? Sorry that was worded rather strangely. What I mean is: If I do manual focus, would I be able to focus at closer distance than if I just used auto-focus? Sometimes, it "feels" like if I get up close and try to auto-focus, it can't lock, but then if I switch to manual, I can get focus easily.
02-19-2016, 08:34 AM - 1 Like   #6
Pentaxian
Na Horuk's Avatar

Join Date: Feb 2012
Location: Slovenia, probably
Photos: Gallery | Albums
Posts: 10,872
Macro just means that it is capable of focusing really really closely, thus giving you high magnification. Usually using manual focus is the best for this, because DoF is super thin in macro range (makes it difficult for AF), and also most users don't know exactly when they get "too close" (any lens has a minimum focus distance, under which it will not be capable of focusing; AF or MF).

To do macro with that lens: 1) On aperture ring, push button and lock it into A mode. This will let you use Av, P and other modes on modern DSLRs.
2) Select Av mode on camera mode dial
3) Choose f8-f14 for good DoF. Shutter speed should be around 1/200 or faster.
4) Select MF (manual focus) and twist focus ring away from infinity, all the way to closest possible focus. Now go toward an object until it becomes "in focus". If your camera has Live view and Focus peaking, you can do that, its a helpful tool to see exactly where focus is.
4.5) AF is usually not used for macro. There is no need for it, because you always get max magnification at nearest focus. Use manual focus and only adjust it a little, do the rest by moving camera closer or further. AF is great for non-macro work (portraiture, landscapes, animal photography), so its good to have that. You can insist on using it in macro range, but it will not be super reliable, nor super precise (well, it will be precise, just not in the way that you probably want it to be). Macro is just such a niche thing due to the high magnification and shallow DoF that the only way to really get what you want is to do it manually. Using tripods, lights, timer helps as well.
5) Take photo. If possible, use Tripod and 2sec timer. In macro range, even a small move of camera can completely change the framing and focus.

Edit: Also, there are different versions of FA 100mm macro. Some need adapter to go all the way to 1:1 macro, though 1:2 is often more than enough. Some macro lenses have focus clamp and focus limiter. The clamp should only be used when you are doing things manually and want to make sure you don't accidentally bump the focus. The focus limiter will prevent AF from going into or out of the macro range. It is a useful tool, but none of the newest Pentax macro lenses seem to have it. I think the lens you mentioned does not have it, but check your copy for switches and knobs to be sure. I think that of 100mm macro, only the Pentax F 100mm macro has focus limiter.

Last edited by Na Horuk; 02-19-2016 at 08:40 AM.
02-19-2016, 08:45 AM   #7
Senior Member




Join Date: Jan 2016
Posts: 240
Original Poster
QuoteOriginally posted by Na Horuk Quote
Macro just means that it is capable of focusing really really closely, thus giving you high magnification. Usually using manual focus is the best for this, because DoF is super thin in macro range (makes it difficult for AF), and also most users don't know exactly when they get "too close" (any lens has a minimum focus distance, under which it will not be capable of focusing; AF or MF).

To do macro with that lens: 1) On aperture ring, push button and lock it into A mode. This will let you use Av, P and other modes on modern DSLRs.
2) Select Av mode on camera mode dial
3) Choose f8-f14 for good DoF. Shutter speed should be around 1/200 or faster.
4) Select MF (manual focus) and twist focus ring away from infinity, all the way to closest possible focus. Now go toward an object until it becomes "in focus". If your camera has Live view and Focus peaking, you can do that, its a helpful tool to see exactly where focus is.
4.5) AF is usually not used for macro. There is no need for it, because you always get max magnification at nearest focus. Use manual focus and only adjust it a little, do the rest by moving camera closer or further. AF is great for non-macro work (portraiture, landscapes, animal photography), so its good to have that. You can insist on using it in macro range, but it will not be super reliable, nor super precise (well, it will be precise, just not in the way that you probably want it to be). Macro is just such a niche thing due to the high magnification and shallow DoF that the only way to really get what you want is to do it manually. Using tripods, lights, timer helps as well.
5) Take photo. If possible, use Tripod and 2sec timer. In macro range, even a small move of camera can completely change the framing and focus.

Edit: Also, there are different versions of FA 100mm macro. Some need adapter to go all the way to 1:1 macro, though 1:2 is often more than enough. Some macro lenses have focus clamp and focus limiter. The clamp should only be used when you are doing things manually and want to make sure you don't accidentally bump the focus. The focus limiter will prevent AF from going into or out of the macro range. It is a useful tool, but none of the newest Pentax macro lenses seem to have it. I think the lens you mentioned does not have it, but check your copy for switches and knobs to be sure. I think that of 100mm macro, only the Pentax F 100mm macro has focus limiter.
Hi,

Thanks for the detailed steps, which I'll try when I get home later.

FYI, the lens I got doesn't have clamp or limit. There's another one on sale now, that is an "F", rather than an "FA", that has limit (not sure about lock):

SMC Pentax F 100mm 1 2 8 Macro AF Objektv Gebraucht | eBay

It's going to be quite expensive !!

Jim
02-19-2016, 08:52 AM   #8
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 9,843
QuoteOriginally posted by LeDave Quote
Shoot at f11 or higher.
?????

02-19-2016, 08:55 AM - 2 Likes   #9
Pentaxian




Join Date: Dec 2010
Location: Ontario
Photos: Gallery
Posts: 2,561
QuoteOriginally posted by ohaya Quote
Hi,

Thanks. So is it correct that I should be able to focus this lens as closely if I do it automatically as if I were to do it manually? Sorry that was worded rather strangely. What I mean is: If I do manual focus, would I be able to focus at closer distance than if I just used auto-focus? Sometimes, it "feels" like if I get up close and try to auto-focus, it can't lock, but then if I switch to manual, I can get focus easily.
Optimally, yes, it should be able to focus just as closely in AF as in MF.

I've only used the DFA100 and DFA50, but if they miss AF they will go hunting like mad. There is some light lost at higher magnifications, so especially in the 0.5 to 1x magnification ranges with those two lenses, I've found AF to be significantly less reliable than at 'normal' focusing distances and MF is preferred.

You will also have a hard time telling if you are below the minimum focus distance and you try to AF. Your lens lists 45cm minimum focusing distance, so if your subject is 44cm away and you have it try to AF, it will just spin around unable to find a lock. Here you would be much better off manually setting it to the minimum, and moving back and forth as suggested earlier.

Nailing the focus can be very frustrating at closeup and macro distances. Practice, more practice, and even more practice. Expect a high failure rate at the start, but it does get much easier
02-19-2016, 09:13 AM   #10
Senior Member




Join Date: Apr 2015
Posts: 133
QuoteOriginally posted by Na Horuk Quote
Macro just means that it is capable of focusing really really closely, thus giving you high magnification.
This is the key here. Macro isn't a mode that you have to enable or anything like that*, but it only achieves it's highest magnification (i.e.: "1:1", "0.5x" or whatever) when you're focusing on something really close up to the front element. That's why you'll sometimes see different magnification ratings printed on the barrel of some lenses. As you focus more closely and the barrel begins to extend out, you can see what sort of magnification you're actually getting at that focus distance. It's not absolutely critical to get the absolute maximum magnification, but if you're looking to get those shots where the small thing just seems so huge in the frame, this is why you get a macro lens and it's good to have an awareness of that fact.

* some lenses may actually have a macro switch or limiter switch that limits how closely the lens can focus. This is useful if you're using the auto focus motor and don't want it to venture into "macro territory" unnecessarily. Your lens is not one of those lenses
02-19-2016, 09:31 AM   #11
Senior Member




Join Date: Jan 2016
Posts: 240
Original Poster
Hi,

Thanks to everyone !!
02-19-2016, 10:33 AM   #12
Pentaxian
CarlJF's Avatar

Join Date: Sep 2014
Location: Quebec City
Posts: 741
When I'm not concerned about absolutely getting the highest magnification, I often use AF.C. Useful for flowers on a windy day or small critters moving around.
02-19-2016, 05:38 PM   #13
Pentaxian
Na Horuk's Avatar

Join Date: Feb 2012
Location: Slovenia, probably
Photos: Gallery | Albums
Posts: 10,872
QuoteOriginally posted by CarlJF Quote
When I'm not concerned about absolutely getting the highest magnification, I often use AF.C. Useful for flowers on a windy day or small critters moving around.
Makes sense, in macro if you use AF, it should be tracking. But tracking, AF.C, expanded focus points, can be complicated and take a while to master (I haven't, pretty much never use it)
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
100mm, auto-focus, camera, fa, lens, lenses, macro, pentax help, photography, reviews, troubleshooting
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Macro Use my new D FA 100mm f2.8 macro wr KDD Post Your Photos! 9 01-22-2016 02:31 PM
100mm Macro A compared to new 90mm Macro Rob Jaffe Pentax Medium Format 15 07-21-2014 08:40 AM
how to use to do macro work Photoshop SFEAR Digital Processing, Software, and Printing 3 04-21-2011 06:29 PM
When/How to use Macro Switch? hockmasm Pentax SLR Lens Discussion 9 09-23-2010 03:59 AM
Lens hoods - Why use them? How to know what type to use? noahpurdy Troubleshooting and Beginner Help 12 12-05-2009 11:30 AM



All times are GMT -7. The time now is 01:23 AM. | 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