M 75-150mm f/4 vs M 85mm f/2

**samski_1** · 07-07-2010, 04:48 AM

I currently have a M 85mm f/2 and was considering replacing it with a M 75-150mm f/4 for versatility. I am very happy with the quality of the 85 pics and wondered wether there would be much drop off with the zoom. The reviews for the zoom on this site are very good but I'm not sure how it would compare to the prime. Would the drop in max aperture have much effect on bokeh when I mainly use it for taking pics of my kids and other animals? I have not used a manual zoom on my K7 - do you still get sharp pics if setting the focal length in one position all the time? Lastly, why is the zoom so cheap if it is as good as people rate it?
Opinions from people who have used both lenses would be much appreciated.

Adam · 07-07-2010, 04:57 AM

M zooms are cheap because they're tedious to use on digital, I'd guess. If you mostly take portraits, I'd say the extra reach of the zoom would be redundant. The two added stops of the 85mm are worth keeping, IMO, and since you've already got the ideal FL for portraits, why switch to a heavier lens?

GeneV · 07-07-2010, 05:02 AM

The 75-150 is so cheap, that it does not make sense to "replace" the 85/2 with it. Just add it to your collection and use it when you need it. I own the 75-150, and it is a great lens, but the 85/2 is another animal altogether. If I did not already own the FA77/1.8, I would have sought out the 85/2 a long time ago.

**samski_1** · 07-07-2010, 05:06 AM

Originally posted by Adam

M zooms are cheap because they're tedious to use on digital, I'd guess. If you mostly take portraits, I'd say the extra reach of the zoom would be redundant. The two added stops of the 85mm are worth keeping, IMO, and since you've already got the ideal FL for portraits, why switch to a heavier lens?

Thanks Adam,
The reason for going longer is because my boys are getting harder to keep up with and to get more animal shots. Most of my photography is done outdoors. The weight is certainly a concern too.

**samski_1** · 07-07-2010, 05:13 AM

Originally posted by GeneV

The 75-150 is so cheap, that it does not make sense to "replace" the 85/2 with it. Just add it to your collection and use it when you need it. I own the 75-150, and it is a great lens, but the 85/2 is another animal altogether. If I did not already own the FA77/1.8, I would have sought out the 85/2 a long time ago.

I'm currently poor and my wife would start removing essential organs if I accumulate more lenses.
Is the picture quality greatly better from the FA77 than the M85 or is the benefit mostly in the more modern attributes it has?

GeneV · 07-07-2010, 05:32 AM

Originally posted by samski_1

I'm currently poor and my wife would start removing essential organs if I accumulate more lenses.
Is the picture quality greatly better from the FA77 than the M85 or is the benefit mostly in the more modern attributes it has?

To start with, the FA77 will cost an essential organ compared to either of those lenses. However, it was one of the first autofocus prime lenses I bought, because it extended the "normal" zooms in the kit range both in reach and in speed.

I've seen the 75-150 go for $70 US recently. That is plasma rather than organ donation.

arpaagent · 07-07-2010, 06:22 AM

Originally posted by samski_1

I'm currently poor and my wife would start removing essential organs if I accumulate more lenses.
Is the picture quality greatly better from the FA77 than the M85 or is the benefit mostly in the more modern attributes it has?

FA77 might be slightly better than the M85 optically, but it is hard to tell in most situations. I had both (just sold my M85!

) and had done a couple tests, and the two lenses are pretty similar in terms of IQ and CA, etc.

FA77 is very useful for AF and auto exposure modes.

GeneV · 07-07-2010, 10:05 AM

Originally posted by arpaagent

FA77 might be slightly better than the M85 optically, but it is hard to tell in most situations. I had both (just sold my M85!

) and had done a couple tests, and the two lenses are pretty similar in terms of IQ and CA, etc.

FA77 is very useful for AF and auto exposure modes.

I did not have the 85/2, so the FA77 Ltd was the obvious choice for those reasons. It was much cheaper when I bought it than it is now, but it still would have been a splurge for someone who was cash-strapped.

**samski_1** · 07-07-2010, 02:04 PM

Originally posted by GeneV

I did not have the 85/2, so the FA77 Ltd was the obvious choice for those reasons. It was much cheaper when I bought it than it is now, but it still would have been a splurge for someone who was cash-strapped.

I have seen what the 77's have been selling for which is why I bought the 85. The idea was to upgrade to the 77 later but I have been so impressed with the 85 I just wanted to know if it was worth it.

Adam · 07-07-2010, 03:56 PM

If you like the 85mm FL and like smooth bokeh for portraiture, I'd recommend this lens: Pentax Lens Review Database - SMC Pentax-FA* 85mm F1.4 [IF] Lens Reviews

It's what I use 90% of the time and you can see my comments on the FA* 85mm here: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/103108-fa*-85m...s-my-mind.html

**samski_1** · 07-07-2010, 05:40 PM

Originally posted by Adam

If you like the 85mm FL and like smooth bokeh for portraiture, I'd recommend this lens: Pentax Lens Review Database - SMC Pentax-FA* 85mm F1.4 [IF] Lens Reviews

It's what I use 90% of the time and you can see my comments on the FA* 85mm here: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/103108-fa*-85m...s-my-mind.html

I have been watching that thread for some time with envy and would love to have one but will have to wait until my old man hands down the goldmine first.

GeneV · 07-08-2010, 06:59 AM

Originally posted by samski_1

I have seen what the 77's have been selling for which is why I bought the 85. The idea was to upgrade to the 77 later but I have been so impressed with the 85 I just wanted to know if it was worth it.

It has been about 3 years, but I seem to recall that I paid about half for the FA77 compared to what this lens fetches now. I don't think I would have gone near it for $850. I wish I'd picked up the FA31 back then.

07-07-2010, 04:48 AM	#1
samski_1 Site Supporter Join Date: Apr 2010 Location: Tasmania Photos: Albums Posts: 349	M 75-150mm f/4 vs M 85mm f/2 I currently have a M 85mm f/2 and was considering replacing it with a M 75-150mm f/4 for versatility. I am very happy with the quality of the 85 pics and wondered wether there would be much drop off with the zoom. The reviews for the zoom on this site are very good but I'm not sure how it would compare to the prime. Would the drop in max aperture have much effect on bokeh when I mainly use it for taking pics of my kids and other animals? I have not used a manual zoom on my K7 - do you still get sharp pics if setting the focal length in one position all the time? Lastly, why is the zoom so cheap if it is as good as people rate it? Opinions from people who have used both lenses would be much appreciated.

07-07-2010, 03:56 PM	#10
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	If you like the 85mm FL and like smooth bokeh for portraiture, I'd recommend this lens: Pentax Lens Review Database - SMC Pentax-FA* 85mm F1.4 [IF] Lens Reviews It's what I use 90% of the time and you can see my comments on the FA* 85mm here: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/103108-fa-85m...s-my-mind.html Adam* PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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07-07-2010, 04:57 AM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	M zooms are cheap because they're tedious to use on digital, I'd guess. If you mostly take portraits, I'd say the extra reach of the zoom would be redundant. The two added stops of the 85mm are worth keeping, IMO, and since you've already got the ideal FL for portraits, why switch to a heavier lens?

07-07-2010, 05:02 AM	#3
GeneV Veteran Member Join Date: Oct 2008 Location: Albuquerque NM Photos: Albums Posts: 9,830	The 75-150 is so cheap, that it does not make sense to "replace" the 85/2 with it. Just add it to your collection and use it when you need it. I own the 75-150, and it is a great lens, but the 85/2 is another animal altogether. If I did not already own the FA77/1.8, I would have sought out the 85/2 a long time ago.

07-07-2010, 05:06 AM	#4
samski_1 Site Supporter Join Date: Apr 2010 Location: Tasmania Photos: Albums Posts: 349 Original Poster	Originally posted by Adam M zooms are cheap because they're tedious to use on digital, I'd guess. If you mostly take portraits, I'd say the extra reach of the zoom would be redundant. The two added stops of the 85mm are worth keeping, IMO, and since you've already got the ideal FL for portraits, why switch to a heavier lens? Thanks Adam, The reason for going longer is because my boys are getting harder to keep up with and to get more animal shots. Most of my photography is done outdoors. The weight is certainly a concern too.

07-07-2010, 05:13 AM	#5
samski_1 Site Supporter Join Date: Apr 2010 Location: Tasmania Photos: Albums Posts: 349 Original Poster	Originally posted by GeneV The 75-150 is so cheap, that it does not make sense to "replace" the 85/2 with it. Just add it to your collection and use it when you need it. I own the 75-150, and it is a great lens, but the 85/2 is another animal altogether. If I did not already own the FA77/1.8, I would have sought out the 85/2 a long time ago. I'm currently poor and my wife would start removing essential organs if I accumulate more lenses. Is the picture quality greatly better from the FA77 than the M85 or is the benefit mostly in the more modern attributes it has?

07-07-2010, 05:32 AM	#6
GeneV Veteran Member Join Date: Oct 2008 Location: Albuquerque NM Photos: Albums Posts: 9,830	Originally posted by samski_1 I'm currently poor and my wife would start removing essential organs if I accumulate more lenses. Is the picture quality greatly better from the FA77 than the M85 or is the benefit mostly in the more modern attributes it has? To start with, the FA77 will cost an essential organ compared to either of those lenses. However, it was one of the first autofocus prime lenses I bought, because it extended the "normal" zooms in the kit range both in reach and in speed. I've seen the 75-150 go for $70 US recently. That is plasma rather than organ donation.

07-07-2010, 06:22 AM	#7
arpaagent Veteran Member Join Date: Sep 2008 Location: Raleigh, NC Photos: Gallery Posts: 803	Originally posted by samski_1 I'm currently poor and my wife would start removing essential organs if I accumulate more lenses. Is the picture quality greatly better from the FA77 than the M85 or is the benefit mostly in the more modern attributes it has? FA77 might be slightly better than the M85 optically, but it is hard to tell in most situations. I had both (just sold my M85! ) and had done a couple tests, and the two lenses are pretty similar in terms of IQ and CA, etc. FA77 is very useful for AF and auto exposure modes.

07-07-2010, 10:05 AM	#8
GeneV Veteran Member Join Date: Oct 2008 Location: Albuquerque NM Photos: Albums Posts: 9,830	Originally posted by arpaagent FA77 might be slightly better than the M85 optically, but it is hard to tell in most situations. I had both (just sold my M85! ) and had done a couple tests, and the two lenses are pretty similar in terms of IQ and CA, etc. FA77 is very useful for AF and auto exposure modes. I did not have the 85/2, so the FA77 Ltd was the obvious choice for those reasons. It was much cheaper when I bought it than it is now, but it still would have been a splurge for someone who was cash-strapped.

07-07-2010, 02:04 PM	#9
samski_1 Site Supporter Join Date: Apr 2010 Location: Tasmania Photos: Albums Posts: 349 Original Poster	Originally posted by GeneV I did not have the 85/2, so the FA77 Ltd was the obvious choice for those reasons. It was much cheaper when I bought it than it is now, but it still would have been a splurge for someone who was cash-strapped. I have seen what the 77's have been selling for which is why I bought the 85. The idea was to upgrade to the 77 later but I have been so impressed with the 85 I just wanted to know if it was worth it.

07-07-2010, 05:40 PM	#11
samski_1 Site Supporter Join Date: Apr 2010 Location: Tasmania Photos: Albums Posts: 349 Original Poster	Originally posted by Adam If you like the 85mm FL and like smooth bokeh for portraiture, I'd recommend this lens: Pentax Lens Review Database - SMC Pentax-FA* 85mm F1.4 [IF] Lens Reviews It's what I use 90% of the time and you can see my comments on the FA* 85mm here: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/103108-fa*-85m...s-my-mind.html I have been watching that thread for some time with envy and would love to have one but will have to wait until my old man hands down the goldmine first.

07-08-2010, 06:59 AM	#12
GeneV Veteran Member Join Date: Oct 2008 Location: Albuquerque NM Photos: Albums Posts: 9,830	Originally posted by samski_1 I have seen what the 77's have been selling for which is why I bought the 85. The idea was to upgrade to the 77 later but I have been so impressed with the 85 I just wanted to know if it was worth it. It has been about 3 years, but I seem to recall that I paid about half for the FA77 compared to what this lens fetches now. I don't think I would have gone near it for $850. I wish I'd picked up the FA31 back then.