100mm SMC M f4 or f2.8

ollie31770 · 04-10-2012, 05:05 AM

Which lens should I get?
The f2.8 seems to be cheaper.
Thanks

**baro-nite** · 04-10-2012, 05:20 AM

These are rather different beasts; the f4 is a macro lens. Are you interested in macro shooting? The f2.8 is, of course, a faster lens. Do you need the extra speed, or the thin depth of field possibilities?

ollie31770 · 04-10-2012, 05:28 AM

I was looking for a macro lens

**baro-nite** · 04-10-2012, 05:35 AM

OK, just to be clear, if the f/2.8 lens is the Pentax-M, it is not macro. There are 100/2.8 macros from Pentax (and others), but they are generally going to cost more than the Pentax-M 1:4 100mm macro.

bluestringer · 04-10-2012, 06:19 AM

I have the 100 f4 macro and love it. It's extremely sharp, and can be found for under 100 bucks. It only does 1:2, but you can still get some really good closeups with it.

abacus07 · 04-10-2012, 12:21 PM

Agreed. These are two very different lenses. The M100/2.8 would be an excellent long portrait lens and a cheap 85mm option. I have the M135/3.5 and the min focus distance (mag factor) is a limiting factor. Pretty much impossible to do macro or close focus w/o tubes. the M100/4 is at the top of my wish list as a versatile telephoto. It will take a nice portrait but it's an outstanding macro lens and a useful macro distance. My M50f4macro is too short for a lot of things I want to do.

RioRico · 04-10-2012, 12:30 PM

Alternatives: https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html

**squareeyes** · 04-10-2012, 12:32 PM

I've used it for copy work and macros. Pretty sharp at all apertures...

Best regards

eddie1960 · 04-10-2012, 12:39 PM

the M100 2.8 is a nice small inexpensive portrait and low light option. it can suffer some pretty nasty PF though (as i discovered shooting a woodpecker in a tree in early spring)

without tubes though it's no macro

the m100 f4 is a pretty decent compact Macro from what i have seen though it needs tubes to be 1:1 as well, (50mm auto extension tube)

The Legendary A 100 2.8 is a true 1:1 macro and fast but it sells for a tonne of dosh

the F 100 2.8 is 1:1 and fast and AF and sells for about half the price of the A (though still 3 X the price of the M100 F4) - the FA 100 sells for similar pricing but adds a focus limiter - essentially it is the Predecessor to the current DFA at half the price

Edit If you are looking manual focus you should look at the Lester Dine 105 2.8 - prices have gotten a little silly lately but it is an excellent macro (it was the Dentist lens of choice in the past)

Jean Poitiers · 04-10-2012, 01:37 PM

Bonjour,

I went and did a silly thing last weekend at a swap meet ... pick up a M 100 f4 Macro. Just saw it and boom, had to have it ... and soon I will have maybe a shoot-off between it and the D FA 100 f2.8 Macro WR. Maybe not a fair competition, but I want to play with the "M" macro (1:2) with some tubes, etc., since it has an Ap ring ... and like I said, I did a silly thing ... damned LBA! Any suggestions ... any input is appreciated for the future tubes et al.

Salut, J Frog

**rbefly** · 04-11-2012, 04:21 AM

Hi Ollie,
If you're looking for a good macro for around $100.00 USD, the Pentax M 100mm Macro is a great choice.
Here's a few samples from last weekend, shot with a Pentax K-7 + the M100 f/4.0. no filters or extensions, just the camera and lens, hand-held.
Ron

04-10-2012, 05:05 AM	#1
ollie31770 New Member Join Date: Mar 2012 Posts: 8	100mm SMC M f4 or f2.8 Which lens should I get? The f2.8 seems to be cheaper. Thanks

04-10-2012, 06:19 AM	#5
bluestringer Veteran Member Join Date: Nov 2011 Location: Cotton fields of South Georgia Photos: Gallery Posts: 2,748	I have the 100 f4 macro and love it. It's extremely sharp, and can be found for under 100 bucks. It only does 1:2, but you can still get some really good closeups with it. Last edited by bluestringer; 04-10-2012 at 03:40 PM.

04-10-2012, 12:32 PM	#8
squareeyes Site Supporter Join Date: Aug 2010 Photos: Gallery Posts: 189	Pentax M 100mm f/4 Macro works for me I've used it for copy work and macros. Pretty sharp at all apertures... Best regards

04-10-2012, 01:37 PM	#10
Jean Poitiers Pentaxian Join Date: Apr 2011 Location: Lost in translation ... Photos: Gallery \| Albums Posts: 18,076	100mm Macro shoot-off ... Bonjour, I went and did a silly thing last weekend at a swap meet ... pick up a M 100 f4 Macro. Just saw it and boom, had to have it ... and soon I will have maybe a shoot-off between it and the D FA 100 f2.8 Macro WR. Maybe not a fair competition, but I want to play with the "M" macro (1:2) with some tubes, etc., since it has an Ap ring ... and like I said, I did a silly thing ... damned LBA! Any suggestions ... any input is appreciated for the future tubes et al. *Salut, J Frog*

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
SMC D FA 100mm 2.8 Macro WR	Painter	Pentax SLR Lens Discussion	6	06-06-2010 01:10 PM

04-10-2012, 05:20 AM	#2
baro-nite Loyal Site Supporter Join Date: Aug 2011 Location: North Carolina, USA Photos: Gallery \| Albums Posts: 5,295	These are rather different beasts; the f4 is a macro lens. Are you interested in macro shooting? The f2.8 is, of course, a faster lens. Do you need the extra speed, or the thin depth of field possibilities?

04-10-2012, 05:28 AM	#3
ollie31770 New Member Join Date: Mar 2012 Posts: 8 Original Poster	I was looking for a macro lens

04-10-2012, 05:35 AM	#4
baro-nite Loyal Site Supporter Join Date: Aug 2011 Location: North Carolina, USA Photos: Gallery \| Albums Posts: 5,295	OK, just to be clear, if the f/2.8 lens is the Pentax-M, it is not macro. There are 100/2.8 macros from Pentax (and others), but they are generally going to cost more than the Pentax-M 1:4 100mm macro.

04-10-2012, 12:21 PM	#6
abacus07 Veteran Member Join Date: Oct 2010 Location: Taiwan Photos: Gallery \| Albums Posts: 1,075	Agreed. These are two very different lenses. The M100/2.8 would be an excellent long portrait lens and a cheap 85mm option. I have the M135/3.5 and the min focus distance (mag factor) is a limiting factor. Pretty much impossible to do macro or close focus w/o tubes. the M100/4 is at the top of my wish list as a versatile telephoto. It will take a nice portrait but it's an outstanding macro lens and a useful macro distance. My M50f4macro is too short for a lot of things I want to do.

04-10-2012, 12:30 PM	#7
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Alternatives: https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html

04-10-2012, 12:39 PM	#9
eddie1960 Veteran Member Join Date: Aug 2010 Location: Toronto Photos: Gallery \| Albums Posts: 13,667	the M100 2.8 is a nice small inexpensive portrait and low light option. it can suffer some pretty nasty PF though (as i discovered shooting a woodpecker in a tree in early spring) without tubes though it's no macro the m100 f4 is a pretty decent compact Macro from what i have seen though it needs tubes to be 1:1 as well, (50mm auto extension tube) The Legendary A 100 2.8 is a true 1:1 macro and fast but it sells for a tonne of dosh the F 100 2.8 is 1:1 and fast and AF and sells for about half the price of the A (though still 3 X the price of the M100 F4) - the FA 100 sells for similar pricing but adds a focus limiter - essentially it is the Predecessor to the current DFA at half the price Edit If you are looking manual focus you should look at the Lester Dine 105 2.8 - prices have gotten a little silly lately but it is an excellent macro (it was the Dentist lens of choice in the past)