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01-29-2011, 10:28 PM   #1
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Macro lens AF speed/noise...?

I'll be getting myself a macro lens soon to use with my k-r.
My previous camera had half-decent macro ability, and it's really the only thing I'm seriously missing.
I'd like to use it as a portrait/general purpose lens too.

I've read some fairly negative things about the af speed/noise of most macro lenses, but am wondering how bad it really is.
I haven't used anything but the two kit lenses (18-55 and 55-300) so if anyone could compare to these it would help me.

The two macro lenses I'm seriously considering are the Sigma 50mm f/2.8 EX DG and the Pentax smc P-D FA 50mm f/2.8.

I understand that for a lot of macro work I'd be using MF (as I did with my old cam), but for portraits and other things AF is nice. Pointless though if it's too slow to be really useful.

01-29-2011, 10:33 PM   #2
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QuoteOriginally posted by photochimp Quote
I'll be getting myself a macro lens soon to use with my k-r.
My previous camera had half-decent macro ability, and it's really the only thing I'm seriously missing.
I'd like to use it as a portrait/general purpose lens too.

I've read some fairly negative things about the af speed/noise of most macro lenses, but am wondering how bad it really is.
I haven't used anything but the two kit lenses (18-55 and 55-300) so if anyone could compare to these it would help me.

The two macro lenses I'm seriously considering are the Sigma 50mm f/2.8 EX DG and the Pentax smc P-D FA 50mm f/2.8.

I understand that for a lot of macro work I'd be using MF (as I did with my old cam), but for portraits and other things AF is nice. Pointless though if it's too slow to be really useful.

macro are a bit slow on focusing, partly because they have to extend all the way out and back in. This is why some "zoom" offered macro with a switch, they don't want the lens extending out all the way (too long for AF).

if you're getting a macro, better off @ 100mm+, the 50mm do not allow lot of working space, you'll be hella close trying to shoot a macro shot, and once you try to get over the 1:1 ratio, you'll be hella even closer. the best macro is the longest macro you can get.
01-29-2011, 10:54 PM   #3
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QuoteOriginally posted by clockwork247 Quote
the best macro is the longest macro you can get.
Is it really that easy?
Isn't it more dependant on what/how you shoot?
I've seen some pretty impressive shots coming from 50mm macros.

I'm thinking of a 50mm because I do like getting close, and for indoor shots I'm finding 100mm or so to be a bit long.
I also like to take shots of chipmunks and squirrels and other small critters that come up very close to me and can see the 50mm being very useful in those situations (the 55mm end of the kit lens is just about too close for that).
I can see how the 100mm would be more useful for some things though... especially insects.

Obviously I have not made up my mind as to what I want, and am open to hearing any suggestions, but I think I'm leaning towards 50mm so far.
01-29-2011, 11:48 PM   #4
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QuoteOriginally posted by photochimp Quote
Is it really that easy?
Isn't it more dependant on what/how you shoot?
I've seen some pretty impressive shots coming from 50mm macros.

I'm thinking of a 50mm because I do like getting close, and for indoor shots I'm finding 100mm or so to be a bit long.
I also like to take shots of chipmunks and squirrels and other small critters that come up very close to me and can see the 50mm being very useful in those situations (the 55mm end of the kit lens is just about too close for that).
I can see how the 100mm would be more useful for some things though... especially insects.

Obviously I have not made up my mind as to what I want, and am open to hearing any suggestions, but I think I'm leaning towards 50mm so far.
trust me on this one, 100mm macro is much easier to work with than 50mm, hell, i even want a 200 or 300mm macro...

i think you have to understand how "macro" work, a macro lens is basically a lens that's capable of focusing stuff at closer distance.

Say your kit lens @ 50mm sitting 2 feet away from the subject making it this (XX) big.

A macro 50mm sitting 2 feet away from the subject will also make it this (XX) big. nothing changes.

What changes is that the macro lens allow you to move closer (say 1 foot closer) and still letting you focus on your subject, because you've moved closer your subject is now (XXX) big. While the kit lens have a minimum focus distance (say 2 feet), once you move closer than 2 feet it won't focus jack shit.

Now do you want to be 2 cm away from the subject you want to take a macro shot of (well maybe not 2cm but you get the idea).

to get a 1:1 macro shot, it's normally the minimum focus distance of the macro lens. here's some number to chew on.
50mm 200 mm 1:1
70mm 257 mm 1:1
90mm 390 mm 1:2
100mm 350 mm 1:1
180mm 460mm 1:1
200mm 500 mm 1:1

now check the price for 200mm and 50mm macro, you'll see why i said longer is better.


Last edited by clockwork247; 01-29-2011 at 11:58 PM.
01-30-2011, 12:22 AM   #5
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There are several macro lenses for K-mount, incl. the 35mm, 50mm and about 100mm.

I would second to consider 100mm and there are 3 superb lenses to choose from: Pentax 100mm WR, Sigma 105mm and Tamron 90mm SP. All are highly regarded lenses and this gives you a nice choice of lens, weight and handling. You simply cannot get wrogn with any of these three.

If you can, to to your local store to try the lenses on your K-r. The weight and size of each lens, in relation to yoru camera handling may be important. For example, I felt that the Sigma 105mm was too heavy with my K-7 and I went for the Tamron for the combination of light weight and lower price.

Hope that the comment will assist and you like the post....
01-30-2011, 07:09 AM   #6
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If you want a sharp general-purpose lens that happens to focus very close, get an expensive autofocus dedicated macro lens like those mentioned.

If you want to focus very close with a sharp lens you already have, get a Raynox DCR-150 or -250. These are just as easy to use as a macro lens.

If you want to focus close but not VERY close, the DA18-55 kit lens will be great for shooting squirrels that run up to within one foot of you.

If you're serious about shooting actual macro (clean 1:1 and thereabouts) and don't want to spend piles of money, get extension (bellows and tubes) and some enlarger lenses: 75mm, 105mm, 160mm. For actual macro, autofocus is useless -- where the system wants to focus may not be where YOU want to focus. Enlarger lenses have edge-to-edge flatfield sharpness and can be had for just a few bucks each. Lenses longer than 75mm can also be used for non-macro photography, reaching infinity focus. Yes, they can become addictive. But they're cheap and good.
01-30-2011, 08:34 AM   #7
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I am considering something longer, but there are some reasons I think a 50mm may be useful to me.

clockwork247... I do want to be able to get very close to the things I'm shooting. That's one thing I really enjoy and am really missing right now. Maybe 100mm would be fine... maybe better, but I know that with the kit lens @ 100mm I find it too long for many thing I like to shoot (though, of course, sometimes the extra reach is great... so either way it'll be a compromise).

hcc... I'd like to go try out some lenses, but I can't find anywhere that has stock around here. Oh, and yeah I like the post just fine...

RioRico... I think of the "If you wants" you posted, I want the first... sharp, general purpose lens that can do 1:1 macro. I only have the kit lenses atm so I know I'm missing out in terms of sharpness/contrast/resolution/ect... Oh, and as for the squirrels, them and the chipmunks come close enough to eat from my hands and sometimes would even touch/sniff my old cam. I need to be able to deal with those situations and I'm pretty sure 100mm would be too long... maybe I'm wrong though as I really don't know what I'm talking about.

I'm not trying to argue with anyone... just trying to make the right choice for me. I've never used a 50mm macro or a 100mm macro or any other macro lens for that matter. I know that I am always wanting to get close to things but just cannot with my current lenses. I also know that 100mm seems a bit long to me for some things.

Thank you all for the replies and please keep em coming.


Last edited by photochimp; 01-30-2011 at 08:39 AM.
01-30-2011, 12:57 PM   #8
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A lens can't focus closer than its focal length; that's also the distance of greatest magnification. So a 50mm macro lets you work as close as 50mm / 2 inches, and a 100mm allows (or forces) you to work no closer than 4 inches, and you'll be at maximum magnification in either case. At 50mm, you *might* be able to get a nose and both eyes of a squirrel on the frame!

I have both 50mm and 90mm macro lenses, but for macro work I'm more likely to use an enlarger lens on extension. (I have the gnarliest such ever, the Schneider Betavaron 50-125 enlarger zoom!) My M42 macro lenses, a Macro-Takumar 50/4 and Vivitar-Konine 90/2.8, are both great as general-purpose lenses, although the MacTak's focusing is best close -- the ring doesn't have much throw for distance focusing. But those are manual lenses. An AF 50 macro transcends that, eh?

So, a suggestion: If you're set on a 50mm, I won't try to argue you away from it. Get it. Use it. If it's all you wanted, excellent! If not, save up for something in the 90-105mm range. And/or buy or borrow a 2X TC for the 50mm, and see if the resultant 100mm length suits you. Good luck!

Last edited by RioRico; 01-30-2011 at 01:05 PM.
01-30-2011, 01:09 PM   #9
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I own the FA50 macro so I can comment.

irst, AF is somewhat noisy, but you won't be using it a lot. You'll be using manual focus more often than not.

The AF throw is looooong to let you focus accurately.

The 50 can be better than the 100 depending on your application. Many people say you should get the longest macro possible, but I don't agree, it really depends. Bokeh will be different, the effect of aperture on your scene also. I'm fully satisfied with my 50 for what it's worth.
01-30-2011, 01:10 PM   #10
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For what you want to shoot ; portraits, squirrels, chipmunks etc. then a 50mm is the better lense for you. However if you are into flying beasties / insects and the like, then the Tamron 90, Pentax 100 or Sigma 105 are much better lenses for you and all three of those are stellar.
01-30-2011, 01:30 PM   #11
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The best macro lens is the one with the focal length you require for the things you'd like to shoot.
I use 100mm because I prefer a longer working distance from my subjects, which can be small and intimidated by a black hole approaching them, but with increasing focal length, there will start to be issues of camera shake for handheld macro photography in ambient light conditions. This is because, with smaller apertures (most useful in macro photography) there will be a resultant decrease in shutter speed for adequate exposure, which may edge close to the typical 1/(focal length) formula for shutter speed that will avert introducing camera shake into the equation.

Hope this helps.
01-30-2011, 03:30 PM   #12
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QuoteOriginally posted by bdery Quote
I own the FA50 macro so I can comment.

irst, AF is somewhat noisy, but you won't be using it a lot. You'll be using manual focus more often than not.

The AF throw is looooong to let you focus accurately.

The 50 can be better than the 100 depending on your application. Many people say you should get the longest macro possible, but I don't agree, it really depends. Bokeh will be different, the effect of aperture on your scene also. I'm fully satisfied with my 50 for what it's worth.
The thing that I see is that because 50mm you need to be so close to take a 1:1 picture, there's almost no advantage over the 100mm (which is further away, but not that much further).

If you're talking about FL, then yes they're different FL, but a "macro" shot is by definition a 1:1 or more...

50mm is more useful than 100 IMO, but not in the context of macro.
01-31-2011, 06:26 AM   #13
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QuoteOriginally posted by clockwork247 Quote
The thing that I see is that because 50mm you need to be so close to take a 1:1 picture, there's almost no advantage over the 100mm (which is further away, but not that much further).
It's true that you need to be closer with a 50, but considering that the focus distance is calculated from the sensor plane, and considering that a 100 mm lens extends much longer, the actual distance between the lens end and the subject is really marginal.
01-31-2011, 07:10 AM   #14
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Some comments: a focus limiter would seem like a useful thing to have for that general purpose AF use. The Sigma 70mm 1:2.8 macro might be worth looking into as well, if the focal length sounds useful.
01-31-2011, 07:26 AM   #15
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If you want to see what the Raynox can do for you check out the Raynox Club

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/74221-raynox-macro-club.html

Here are some examples of what a 50mm 1:1 macro can do. These are from a Sigma A 50mm f/2.8 macro.














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