M 135mm f3.5 or M 100mm f2.8

auto110 · 08-18-2009, 10:08 AM

Hello Everyone.
I am trying to decide between the M 135mm f3.5 and M 100mm 2.8. I want something to shoot wildlife shots and indoor concert shots. My camera is a
K20D. Does anyone out there own both of these lens and if so how do the compare to one another. Photos with each would be a plus!
Thanks for the insight.

**Lowell Goudge** · 08-18-2009, 10:25 AM

I know some people use the 135 F3.5 for indoor concerts, but in myu opinion you would be better off with the 135 F2.5.

Also a 100mm F2.8 is a little slow for indoors (again IMO) and you might like an 85mm F1.4 (samyang) or F1.8/9 Tak, SMC Tak or K mount

For wild life, neither of the lenses you mention are any where near long enough, you would want a minimum of 200mm and perhaps 300 or 400 mm

Marc Sabatella · 08-18-2009, 12:04 PM

Originally posted by auto110

Hello Everyone.
I am trying to decide between the M 135mm f3.5 and M 100mm 2.8. I want something to shoot wildlife shots and indoor concert shots. My camera is a
K20D. Does anyone out there own both of these lens and if so how do the compare to one another. Photos with each would be a plus!

I own both, and shoot concerts a lot with them. Not so much wildlife, because neither is really long enough for that. I'd say if you don't have or plan to get or carry around a longer telephoto lens as well as this one, and you really see yourself wanting to use this lens for wildlife, I'd probably choose the 135 for the extra length alone, as that would probably trump any of the other tradeoffs I'll mention. But assuming you put aside thoughts of using this for wildlife, here are some other observations:

- I really do like the 100mm field of view on APS-C as a "general purpose telephoto lens", whatever that might mean, although of course like any single focal length, it's too long for some shots and too short for others. But if I wasn't concerned about shooting wildlife and wanted just one telephoto prime, this would be the lens I'd look for first. It's usable for portraits, landscape details, street candids, and plays nicely with a Raynox 150 for macro. I *might* hold out for the "A" version, both for its "A"-ness but also the built in hood. That adds a lot to the price, though, and also makes it much harder to find.

- For speed, f/2.8 is usually good enough. Sure, faster is nice, but DOF starts to really suffer. I rarely shoot concerts faster than f/2.8 even with the lenses I have that can go there. ISO 1600, f/2.8, 1/30" or 1/45", SR, and good timing can get you some great shots, and f/3.5 is only half a stop off that. Go down one notch in shutter speed, raise ISO to 2400, or push the shot in PP and you'll barely notice the difference. A 135/2.8 or 135/2.5 sounds great in theory, but I prefer my M135/3.5 optically to the off-brand 135/2.8 it replaced, and there's something to be said for the compactness of the M series over any of the older Pentax lenses.

- For shooting concerts, 100mm really nails it for me pretty well as the best single focal length, and hoods are less important than they are outdoors (although flare from spotlights happens, too, of course). Again, if I'm going to carry just one telephoto prime for concerts, this is my choice. A 135 would be too long by itself too much of the time, and pairing it with a 50 - as I had been doing - just leaves this huge frustrating gap in the middle. Would I like the M100/2.8 to be faster? Why not, but it's not like there are a ton of faster options at that focal length. The M85/2 would be the one other lens I'd consider, but it's really getting to be short enough that I'd want something else longer to go with it.

- Although I was (and still am) happy with my M100/2.8, and it had largely replaced my M135/3.5 in my bag, things changed when I decided to add a DA70 to the mix. Now the 100 seems too close to the 70 to be worth carrying, so I tend to take the 135 instead. I swear, I like the 100 so much that I feel guilty for this, but the 70 & 135 combo is pretty darned useful. Cooler still, though, would be a 70 & 120, I think, as it closes the focal length gap some and improves speed a bit. I've even entertained the idea of selling both the 100 & 135 and replacing them both with a M120/2.8, but I haven't been able to make myself do it. There's really nothing *wrong* with the 135 as a partner to the 70, and again, I like having that 100 available, even if it stays home most days.

- The M135/3.5 is very good at all apertures, I find, but as you will often read, it does occasionally have a weird soft-focus look with very visible chromatic aberration used wide open. It only pops up rarely - under certain lighting conditions - but when it does, it's tough to control. See my review in the lens review db on this forum for more on this.

- The M100/2.8 is really much better wide open than it has any right to be (certainly much better than the resolution tests I've seen online would suggest). But oddly, it doesn't get much better as it stops down - f/8 seems barely better than f/2.8, and I'm not convinced it beats my 50-200 at the apertures they share. Between that, the relatively short focal length, and lack of a hood, really, I prefer the 50-200 outdoors.

Here are some sample shots (apologies to those who've seen some of these a hundred times before).

First the M100/2.8:

Now the M135/3.5:

All but the last of these would have been shot wide open at ISO 1600 (the last was probably f/5.6 at ISO 200); all were with my K200D.

auto110 · 08-19-2009, 04:43 AM

Thanks guys I appreciate the input.
The details in Marc's reply were especially helpful as were the photos.
After looking at Marc's pictures and reading all of the reviews I decided to go with the
135mm f3.5. I have a FA 28-80 1:3.5-5.6 and I played with it yesterday evening to get a feel for having to shoot at 3.5. I was happy with what I learned. The anti shake on the K20D makes a huge difference in lower light situations.
Again thank you both for taking the time out of your day to help me with my decision.

auto110 · 08-24-2009, 10:36 AM

Well I am happy to say I am the proud owner of a M135/3.5 and I could not be happier.
I am looking forward to using this weekend if not sooner.
Thanks for the guidance Marc. Your photos greatly helped in my purchasing decision.

08-18-2009, 10:08 AM	#1
auto110 Junior Member Join Date: Aug 2009 Location: Eastern US Photos: Gallery Posts: 31	M 135mm f3.5 or M 100mm f2.8 Hello Everyone. I am trying to decide between the M 135mm f3.5 and M 100mm 2.8. I want something to shoot wildlife shots and indoor concert shots. My camera is a K20D. Does anyone out there own both of these lens and if so how do the compare to one another. Photos with each would be a plus! Thanks for the insight.

08-18-2009, 12:04 PM	#3
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Originally posted by auto110 Hello Everyone. I am trying to decide between the M 135mm f3.5 and M 100mm 2.8. I want something to shoot wildlife shots and indoor concert shots. My camera is a K20D. Does anyone out there own both of these lens and if so how do the compare to one another. Photos with each would be a plus! I own both, and shoot concerts a lot with them. Not so much wildlife, because neither is really long enough for that. I'd say if you don't have or plan to get or carry around a longer telephoto lens as well as this one, and you really see yourself wanting to use this lens for wildlife, I'd probably choose the 135 for the extra length alone, as that would probably trump any of the other tradeoffs I'll mention. But assuming you put aside thoughts of using this for wildlife, here are some other observations: - I really do like the 100mm field of view on APS-C as a "general purpose telephoto lens", whatever that might mean, although of course like any single focal length, it's too long for some shots and too short for others. But if I wasn't concerned about shooting wildlife and wanted just one telephoto prime, this would be the lens I'd look for first. It's usable for portraits, landscape details, street candids, and plays nicely with a Raynox 150 for macro. I might hold out for the "A" version, both for its "A"-ness but also the built in hood. That adds a lot to the price, though, and also makes it much harder to find. - For speed, f/2.8 is usually good enough. Sure, faster is nice, but DOF starts to really suffer. I rarely shoot concerts faster than f/2.8 even with the lenses I have that can go there. ISO 1600, f/2.8, 1/30" or 1/45", SR, and good timing can get you some great shots, and f/3.5 is only half a stop off that. Go down one notch in shutter speed, raise ISO to 2400, or push the shot in PP and you'll barely notice the difference. A 135/2.8 or 135/2.5 sounds great in theory, but I prefer my M135/3.5 optically to the off-brand 135/2.8 it replaced, and there's something to be said for the compactness of the M series over any of the older Pentax lenses. - For shooting concerts, 100mm really nails it for me pretty well as the best single focal length, and hoods are less important than they are outdoors (although flare from spotlights happens, too, of course). Again, if I'm going to carry just one telephoto prime for concerts, this is my choice. A 135 would be too long by itself too much of the time, and pairing it with a 50 - as I had been doing - just leaves this huge frustrating gap in the middle. Would I like the M100/2.8 to be faster? Why not, but it's not like there are a ton of faster options at that focal length. The M85/2 would be the one other lens I'd consider, but it's really getting to be short enough that I'd want something else longer to go with it. - Although I was (and still am) happy with my M100/2.8, and it had largely replaced my M135/3.5 in my bag, things changed when I decided to add a DA70 to the mix. Now the 100 seems too close to the 70 to be worth carrying, so I tend to take the 135 instead. I swear, I like the 100 so much that I feel guilty for this, but the 70 & 135 combo is pretty darned useful. Cooler still, though, would be a 70 & 120, I think, as it closes the focal length gap some and improves speed a bit. I've even entertained the idea of selling both the 100 & 135 and replacing them both with a M120/2.8, but I haven't been able to make myself do it. There's really nothing wrong with the 135 as a partner to the 70, and again, I like having that 100 available, even if it stays home most days. - The M135/3.5 is very good at all apertures, I find, but as you will often read, it does occasionally have a weird soft-focus look with very visible chromatic aberration used wide open. It only pops up rarely - under certain lighting conditions - but when it does, it's tough to control. See my review in the lens review db on this forum for more on this. - The M100/2.8 is really much better wide open than it has any right to be (certainly much better than the resolution tests I've seen online would suggest). But oddly, it doesn't get much better as it stops down - f/8 seems barely better than f/2.8, and I'm not convinced it beats my 50-200 at the apertures they share. Between that, the relatively short focal length, and lack of a hood, really, I prefer the 50-200 outdoors. Here are some sample shots (apologies to those who've seen some of these a hundred times before). First the M100/2.8: Now the M135/3.5: All but the last of these would have been shot wide open at ISO 1600 (the last was probably f/5.6 at ISO 200); all were with my K200D. Last edited by Marc Sabatella; 08-18-2009 at 12:13 PM.

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08-18-2009, 10:25 AM	#2
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	I know some people use the 135 F3.5 for indoor concerts, but in myu opinion you would be better off with the 135 F2.5. Also a 100mm F2.8 is a little slow for indoors (again IMO) and you might like an 85mm F1.4 (samyang) or F1.8/9 Tak, SMC Tak or K mount For wild life, neither of the lenses you mention are any where near long enough, you would want a minimum of 200mm and perhaps 300 or 400 mm

08-19-2009, 04:43 AM	#4
auto110 Junior Member Join Date: Aug 2009 Location: Eastern US Photos: Gallery Posts: 31 Original Poster	Thanks guys I appreciate the input. The details in Marc's reply were especially helpful as were the photos. After looking at Marc's pictures and reading all of the reviews I decided to go with the 135mm f3.5. I have a FA 28-80 1:3.5-5.6 and I played with it yesterday evening to get a feel for having to shoot at 3.5. I was happy with what I learned. The anti shake on the K20D makes a huge difference in lower light situations. Again thank you both for taking the time out of your day to help me with my decision.

08-24-2009, 10:36 AM	#5
auto110 Junior Member Join Date: Aug 2009 Location: Eastern US Photos: Gallery Posts: 31 Original Poster	Well I am happy to say I am the proud owner of a M135/3.5 and I could not be happier. I am looking forward to using this weekend if not sooner. Thanks for the guidance Marc. Your photos greatly helped in my purchasing decision.