Questions regarding Pentax-D FA 100mm f2.8 macro

katyusha · 08-04-2021, 06:38 AM

One of my friends recommended this lens to me when I ask for a 100mm macro lens produced by Pentax for best value of money, and for my self, I am using a Sony full frame camera (A7R2) and I was wondering is it possible for me to use that Pentax-D FA 100mm f2.8 macro （non-water resist）on it with adapter ring without electrical contacts?

Or by another phrasing……am I able to use the manual focus without attached it onto any camera?（Do I need power when trying to focus manually with the focus ring?）

And can its optical quality meet the requirements of a 42-megapixel CMOS while doing film digitizing？

Last edited by katyusha; 08-04-2021 at 06:54 AM.

**UncleVanya** · 08-04-2021, 07:09 AM - **3 Likes**

Originally posted by katyusha

One of my friends recommended this lens to me when I ask for a 100mm macro lens produced by Pentax for best value of money, and for my self, I am using a Sony full frame camera (A7R2) and I was wondering is it possible for me to use that Pentax-D FA 100mm f2.8 macro （non-water resist）on it with adapter ring without electrical contacts?

Or by another phrasing……am I able to use the manual focus without attached it onto any camera?（Do I need power when trying to focus manually with the focus ring?）

And can its optical quality meet the requirements of a 42-megapixel CMOS while doing film digitizing？

Judge quality for yourself:

It ain’t easy being cheesy by -vanya_42nd-

That’s my old A7rII with my DFA 100WR manually focused. I used a “DA” style adapter that allows me to control aperture in a crude way (one adapter I have is continuously variable without click stops, The other has discreet click stops but isn’t calibrated and the stops vary on different lenses. In practice Both work fine but the click stop one is easier to replicate a specific setting with.)

Click the image for greater resolution.

EDIT: if you are asking about the non-WR version the options are supposedly the same and the aperture ring will make it easier to use. The focus is mechanical as is the aperture. The upcoming Monster La-ke adapter will offer autofocus on your camera but the adapter isn’t cheap and hasn’t shipped yet.

**pepperberry farm** · 08-04-2021, 07:10 AM - **1 Like**

great lens - it has an aperture ring, correct?

Wheatfield · 08-04-2021, 07:14 AM

Originally posted by katyusha

One of my friends recommended this lens to me when I ask for a 100mm macro lens produced by Pentax for best value of money, and for my self, I am using a Sony full frame camera (A7R2) and I was wondering is it possible for me to use that Pentax-D FA 100mm f2.8 macro （non-water resist）on it with adapter ring without electrical contacts?

Yes

Quote:

Or by another phrasing……am I able to use the manual focus without attached it onto any camera?（Do I need power when trying to focus manually with the focus ring?）

Yes to the first question, no to the second.

Quote:

And can its optical quality meet the requirements of a 42-megapixel CMOS while doing film digitizing？

Yes.

**acoufap** · 08-04-2021, 07:17 AM - **2 Likes**

Originally posted by pepperberry farm

great lens - it has an aperture ring, correct?

SMC Pentax-D FA 100mm F2.8 Macro Reviews - D FA Prime Lenses - Pentax Lens Reviews & Lens Database

aaacb · 08-04-2021, 07:27 AM - **1 Like**

Yes, the lens is very sharp stopped down. I have the WR version and scan with a 36mp K1ii. The main challenge isn't lens sharpness but aligning the film with the plane of focus, at 1:1 reproduction depth of field is minuscule. I use a tripod and a light table, probably would be quicker and more accurate with a slide scanning attachment to guarantee the film is parallel to the sensor.

**ehrwien** · 08-04-2021, 07:36 AM - **1 Like**

In this use case, are there benefits of using a 100mm macro over a 50mm macro?

aaacb · 08-04-2021, 07:49 AM - **2 Likes**

Originally posted by ehrwien

In this use case, are there benefits of using a 100mm macro over a 50mm macro?

Working distance if you're using a tripod, I can't find a way to use my 50 macro because there's no room under the tripod for the light pad

**UncleVanya** · 08-04-2021, 08:11 AM - **2 Likes**

Originally posted by pepperberry farm

great lens - it has an aperture ring, correct?

It depends on which version. The non-WR version has a ring, the WR version does not. I missed that the op specified that version.

**pres589** · 08-04-2021, 08:29 AM - **1 Like**

When there are F, FA, and D-FA versions of this lens that have an aperture ring, I would not bother with the WR version when adapting.

Pentax doesn't seem to have ever sold a bad *prime* lens that they labeled as a macro. Zooms are something else and not really part of this statement.

There's a whole lot of k-mount primes on the used market that may be of interest, from 90 to 105mm. Again, I would get one with an aperture ring if the goal is adapting it to another mount like your Sony's.

**aslyfox** · 08-04-2021, 08:51 AM - **1 Like**

good article to review

Quote:

The Advantages of a Dedicated Macro Lens
Achieving lift-size magnification
By PF Staff in Tutorial Videos on Apr 4, 2016

Read more at: The Advantages of a Dedicated Macro Lens - Tutorial Videos | PentaxForums.com

__________________

Quote:

Pentax-D FA 100mm F2.8 WR Macro Review
Specifications
The lens covers the full 24x36mm format, not just APS-C. The aperture blades are rounded, delivering a smoother bokeh which is important for a macro lens. However, unlike its predecessor, it has no aperture ring.

The optical design is the tried-and-proven formula of the previous generation D FA 100mm F2.8 Macro lens, which in turn had inherited the optical design from the well-respected FA 100mm F2.8 and F 100mm F2.8 macro lenses introduced in 1991 and 1987, respectively. None of these earlier lenses had rounded aperture blades.

Read more at: Pentax-D FA 100mm F2.8 WR Macro Review - Specifications | PentaxForums.com Reviews

AfterPentax Mark II · 08-04-2021, 09:12 AM - **2 Likes**

[

Originally posted by katyusha

And can its optical quality meet the requirements of a 42-megapixel CMOS while doing film digitizing？

Should the question not be: can the 42-megapixel CMOS of your Sony camera meet the optical quality of the D FA 100mm f2.8 Macro?

**MossyRocks** · 08-04-2021, 09:12 AM - **1 Like**

It is a very good lens, my only complaint is that is is awful for astrophotography but there I just wanted to see how it did as I have other very good astro lenses. Also one doesn't generally buy a macro lens with the intent of doing astrophotography.

**UncleVanya** · 08-04-2021, 10:47 AM

Originally posted by MossyRocks

It is a very good lens, my only complaint is that is is awful for astrophotography but there I just wanted to see how it did as I have other very good astro lenses. Also one doesn't generally buy a macro lens with the intent of doing astrophotography.

What specifically failed? Coma? Astigmatism?

**MossyRocks** · 08-04-2021, 11:23 AM

Originally posted by UncleVanya

What specifically failed? Coma? Astigmatism?

Massive amounts of purple fringing that doesn't really go away until one gets to about f/8. It really doesn't do well with very bright point light sources against a very dark background. I have some sample photos showing how it performs for astro and my detailed thoughts here. So my advise it don't use it for astro and love it for everything else it is a great lens. By careful focusing I mean using a bahtinov mask to achieve a proper infinity focus.

08-04-2021, 06:38 AM	#1
katyusha New Member Join Date: May 2021 Posts: 9	Questions regarding Pentax-D FA 100mm f2.8 macro One of my friends recommended this lens to me when I ask for a 100mm macro lens produced by Pentax for best value of money, and for my self, I am using a Sony full frame camera (A7R2) and I was wondering is it possible for me to use that Pentax-D FA 100mm f2.8 macro （non-water resist）on it with adapter ring without electrical contacts? Or by another phrasing……am I able to use the manual focus without attached it onto any camera?（Do I need power when trying to focus manually with the focus ring?） And can its optical quality meet the requirements of a 42-megapixel CMOS while doing film digitizing？ Last edited by katyusha; 08-04-2021 at 06:54 AM.

08-04-2021, 07:09 AM - 3 Likes	#2
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,407	Originally posted by katyusha One of my friends recommended this lens to me when I ask for a 100mm macro lens produced by Pentax for best value of money, and for my self, I am using a Sony full frame camera (A7R2) and I was wondering is it possible for me to use that Pentax-D FA 100mm f2.8 macro （non-water resist）on it with adapter ring without electrical contacts? Or by another phrasing……am I able to use the manual focus without attached it onto any camera?（Do I need power when trying to focus manually with the focus ring?） And can its optical quality meet the requirements of a 42-megapixel CMOS while doing film digitizing？ Judge quality for yourself: It ain’t easy being cheesy by -vanya_42nd- That’s my old A7rII with my DFA 100WR manually focused. I used a “DA” style adapter that allows me to control aperture in a crude way (one adapter I have is continuously variable without click stops, The other has discreet click stops but isn’t calibrated and the stops vary on different lenses. In practice Both work fine but the click stop one is easier to replicate a specific setting with.) Click the image for greater resolution. EDIT: if you are asking about the non-WR version the options are supposedly the same and the aperture ring will make it easier to use. The focus is mechanical as is the aperture. The upcoming Monster La-ke adapter will offer autofocus on your camera but the adapter isn’t cheap and hasn’t shipped yet. Last edited by UncleVanya; 08-04-2021 at 08:14 AM.

08-04-2021, 08:51 AM - 1 Like	#11
aslyfox Seeker of Knowledge Join Date: Aug 2016 Location: Topeka, Kansas Photos: Gallery \| Albums Posts: 24,581	good article to review Quote: The Advantages of a Dedicated Macro Lens Achieving lift-size magnification By PF Staff in Tutorial Videos on Apr 4, 2016 Read more at: The Advantages of a Dedicated Macro Lens - Tutorial Videos \| PentaxForums.com __________________ Quote: Pentax-D FA 100mm F2.8 WR Macro Review Specifications The lens covers the full 24x36mm format, not just APS-C. The aperture blades are rounded, delivering a smoother bokeh which is important for a macro lens. However, unlike its predecessor, it has no aperture ring. The optical design is the tried-and-proven formula of the previous generation D FA 100mm F2.8 Macro lens, which in turn had inherited the optical design from the well-respected FA 100mm F2.8 and F 100mm F2.8 macro lenses introduced in 1991 and 1987, respectively. None of these earlier lenses had rounded aperture blades. Read more at: Pentax-D FA 100mm F2.8 WR Macro Review - Specifications \| PentaxForums.com Reviews Last edited by aslyfox; 08-04-2021 at 09:02 AM.

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08-04-2021, 07:10 AM - 1 Like	#3
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,679	great lens - it has an aperture ring, correct?

08-04-2021, 07:14 AM	#4
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	Originally posted by katyusha One of my friends recommended this lens to me when I ask for a 100mm macro lens produced by Pentax for best value of money, and for my self, I am using a Sony full frame camera (A7R2) and I was wondering is it possible for me to use that Pentax-D FA 100mm f2.8 macro （non-water resist）on it with adapter ring without electrical contacts? Yes Quote: Or by another phrasing……am I able to use the manual focus without attached it onto any camera?（Do I need power when trying to focus manually with the focus ring?） Yes to the first question, no to the second. Quote: And can its optical quality meet the requirements of a 42-megapixel CMOS while doing film digitizing？ Yes.

08-04-2021, 07:17 AM - 2 Likes	#5
acoufap Site Supporter Join Date: Jan 2011 Location: Munich, Germany Photos: Gallery \| Albums Posts: 4,187	Originally posted by pepperberry farm great lens - it has an aperture ring, correct? SMC Pentax-D FA 100mm F2.8 Macro Reviews - D FA Prime Lenses - Pentax Lens Reviews & Lens Database

08-04-2021, 07:27 AM - 1 Like	#6
aaacb Pentaxian Join Date: May 2016 Photos: Gallery Posts: 3,725	Yes, the lens is very sharp stopped down. I have the WR version and scan with a 36mp K1ii. The main challenge isn't lens sharpness but aligning the film with the plane of focus, at 1:1 reproduction depth of field is minuscule. I use a tripod and a light table, probably would be quicker and more accurate with a slide scanning attachment to guarantee the film is parallel to the sensor.

08-04-2021, 07:36 AM - 1 Like	#7
ehrwien Site Supporter Join Date: May 2016 Posts: 2,782	In this use case, are there benefits of using a 100mm macro over a 50mm macro?

08-04-2021, 07:49 AM - 2 Likes	#8
aaacb Pentaxian Join Date: May 2016 Photos: Gallery Posts: 3,725	Originally posted by ehrwien In this use case, are there benefits of using a 100mm macro over a 50mm macro? Working distance if you're using a tripod, I can't find a way to use my 50 macro because there's no room under the tripod for the light pad

08-04-2021, 08:11 AM - 2 Likes	#9
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,407	Originally posted by pepperberry farm great lens - it has an aperture ring, correct? It depends on which version. The non-WR version has a ring, the WR version does not. I missed that the op specified that version.

08-04-2021, 08:29 AM - 1 Like	#10
pres589 Site Supporter Join Date: Jan 2014 Location: Wichita, KS Photos: Albums Posts: 4,529	When there are F, FA, and D-FA versions of this lens that have an aperture ring, I would not bother with the WR version when adapting. Pentax doesn't seem to have ever sold a bad prime lens that they labeled as a macro. Zooms are something else and not really part of this statement. There's a whole lot of k-mount primes on the used market that may be of interest, from 90 to 105mm. Again, I would get one with an aperture ring if the goal is adapting it to another mount like your Sony's.

08-04-2021, 09:12 AM - 2 Likes	#12
AfterPentax Mark II Pentaxian Join Date: Mar 2021 Posts: 1,462	[ Originally posted by katyusha And can its optical quality meet the requirements of a 42-megapixel CMOS while doing film digitizing？ Should the question not be: can the 42-megapixel CMOS of your Sony camera meet the optical quality of the D FA 100mm f2.8 Macro?

08-04-2021, 09:12 AM - 1 Like	#13
MossyRocks Loyal Site Supporter Join Date: Nov 2017 Location: Minnesota Photos: Gallery \| Albums Posts: 2,982	It is a very good lens, my only complaint is that is is awful for astrophotography but there I just wanted to see how it did as I have other very good astro lenses. Also one doesn't generally buy a macro lens with the intent of doing astrophotography.

08-04-2021, 10:47 AM	#14
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,407	Originally posted by MossyRocks It is a very good lens, my only complaint is that is is awful for astrophotography but there I just wanted to see how it did as I have other very good astro lenses. Also one doesn't generally buy a macro lens with the intent of doing astrophotography. What specifically failed? Coma? Astigmatism?

08-04-2021, 11:23 AM	#15
MossyRocks Loyal Site Supporter Join Date: Nov 2017 Location: Minnesota Photos: Gallery \| Albums Posts: 2,982	Originally posted by UncleVanya What specifically failed? Coma? Astigmatism? Massive amounts of purple fringing that doesn't really go away until one gets to about f/8. It really doesn't do well with very bright point light sources against a very dark background. I have some sample photos showing how it performs for astro and my detailed thoughts here. So my advise it don't use it for astro and love it for everything else it is a great lens. By careful focusing I mean using a bahtinov mask to achieve a proper infinity focus.