Fast lens for Pentax (thoughts from Sigma 18-35 F1.8)

**Rondec** · 03-01-2014, 05:24 AM

Primes will always have, at a minimum, smaller size on a zoom. The 18-35 f1.8 may be the exception, but normally you see better sharpness at equivalent f stops, better out of focus rendering, and significantly better flare resistance. This last feature is something that, even with the best coatings, probably won't change since a fast zoom has so much more glass than the prime.

Nicolas06 · 03-01-2014, 06:10 AM

In case of 18-35, it is insanely sharp and as also a very fast aperture while remaining sharp. It still has a flare problem through and from the samples I have seen you doesn't have the color rendition you have typically with high end pentax glass (DA*, even zooms, DA/FA ltd).

Sigma choosed the 18-35 f/1.8 route instead of the 17-50 f/1.8, not only for price; a 18-50 f/1.8 would have trouble to be of same quality as of a 18-35 f/1.8. 3X is a little too much while a such short focal at the begining of the range doesn't help. 24-70 f/1.8 might be easier to design (and something similar already exist in FF with at least f/2 I think).

Zoom vs Prime is not absolute. There focals that zooms handle better than others. A 50-135 or 70-200 tend to give very satisfory results. Transtandard tend to be not that good, in particular wide open, begining of the range. If the sigma change the game it is because of it's 2X range.

DSims · 03-01-2014, 09:10 AM

Originally posted by Nicolas06

In case of 18-35, it is insanely sharp and as also a very fast aperture while remaining sharp. It still has a flare problem through and from the samples I have seen you doesn't have the color rendition you have typically with high end pentax glass (DA*, even zooms, DA/FA ltd).

Sigma choosed the 18-35 f/1.8 route instead of the 17-50 f/1.8, not only for price; a 18-50 f/1.8 would have trouble to be of same quality as of a 18-35 f/1.8. 3X is a little too much while a such short focal at the begining of the range doesn't help. 24-70 f/1.8 might be easier to design (and something similar already exist in FF with at least f/2 I think).

Zoom vs Prime is not absolute. There focals that zooms handle better than others. A 50-135 or 70-200 tend to give very satisfory results. Transtandard tend to be not that good, in particular wide open, begining of the range. If the sigma change the game it is because of it's 2X range.

I completely agree on all points (although I'll just take your word for it on the sharpness - haven't examined that aspect yet, but if it's anything like my Sigma 8-16 it's sharp!).

No one's truly created a great 16/17/18-50/2.8 yet - how could we possibly expect a great f/1.8 lens with that range?!!

Originally posted by starjedi

At the prime side, Pentax for sure can deliver some fast APS-C lens such as 24mm F1.2/35mm F1.2/50mm F1.2/85 F1.2 (their size will still be smaller than FF lenses as 85 F1.2 APS-C only lens will surely be smaller than a FF 85 F1.2). The price will also be lower and at the $1000-$1500 level instead of $2000+ level.

However, it is just a dream as Pentax apparently sticks with the portability on APS-C region and does not have strong motivation to challenge itself due to small market share. And as far as we know, lot of pentax prime lens are in fact ff compatible lens, which simply means that they are lazy to design as a lot of lights are wasted!

As for these primes, however, it may be technically feasible. In a photography culture where people fawn over the recent Fuji X systems, Sony A7 and A7r, and the Sigma 18-35/1.8, it actually pays to make such attention-grabbing products. So if it could easily be done, I would expect someone might be doing it!

But it's not going to be Canon or Nikon, and probably not Sony. A $200 35mm f/1.8 APS-C only lens doesn't necessarily undermine FF when a FF f/1.4 version is available. But an APS-C f/1.2 lens could - especially when in theory it would cost less. And even Pentax doesn't want to go down that road now, with a FF likely coming out. So that leaves only third parties, and Sigma probably doesn't want to undermine sales of it's new 35/1.4 FF Art lens, for example. So who would do it?

VoiceOfReason · 03-01-2014, 09:35 AM

I've never minded weight when it comes to lenses, but that may be because I'm pretty big myself at 6'2" and 255 lb. You should see my hiking kit. Small and light are not of much use if they never leave the bag.

starjedi · 03-01-2014, 09:11 PM

Originally posted by VoiceOfReason

I've never minded weight when it comes to lenses, but that may be because I'm pretty big myself at 6'2" and 255 lb. You should see my hiking kit. Small and light are not of much use if they never leave the bag.

As an apparently exaggerated example, let's try handhold for FA*250-600mm or FA*600mm :-).

VoiceOfReason · 03-01-2014, 09:13 PM

If I could get the FA*250-600 I would DEFINITELY do it. I do it with my 150-500.

starjedi · 03-01-2014, 09:26 PM

Originally posted by VoiceOfReason

If I could get the FA*250-600 I would DEFINITELY do it. I do it with my 150-500.

Haha. 150-500 is only 4.2 pound (:-)) while FA*250-600 is 11.2 pound!

VoiceOfReason · 03-01-2014, 09:29 PM

I'd still do it. That's one of my dream lenses.

reeftool · 03-02-2014, 07:03 AM - **1 Like**

Originally posted by VoiceOfReason

I've never minded weight when it comes to lenses, but that may be because I'm pretty big myself at 6'2" and 255 lb. You should see my hiking kit. Small and light are not of much use if they never leave the bag.

I never thought much or minded the weight of my camera gear either, until recently. It happened very quickly too. Part of the problem is all those years of hiking with large and heavy packs was taking a toll on my body. I'm enjoying myself, getting exercise and thinking I'm doing something good. Maybe good for my blood pressure but I was destroying my spine, knees, and ankles. You don't think about it when you're young.

I still hike, climb, and backpack and I still bring my camera but not not a lot of gear and weight is a big factor. It's not as fun as it used to be.

Nicolas06 · 03-02-2014, 12:40 PM

Some are really dreaming here. Pentax doesn't ofter anything faster than f/2.4 except for 50mm and old FA (limited or not). I don't think we will see any f/1.2 soon.

The thing is they don't want to make something that could hurt their limited lenses.

**Digitalis** · 03-02-2014, 04:44 PM - **1 Like**

The other problem is the lack of contrast for the AF system that many F/1.2 lenses suffer from. I'm sure pentax could figure out a way to get around that proclivity of fast lenses - but it will be probably be expensive.

Pentax K5IIs - SMCP-K 50mm f/1.2 @ f/1.2 ISO 80 1/3200th

DSims · 03-04-2014, 03:23 AM

Originally posted by Nicolas06

Some are really dreaming here. Pentax doesn't ofter anything faster than f/2.4 except for 50mm and old FA (limited or not). I don't think we will see any f/1.2 soon.

The thing is they don't want to make something that could hurt their limited lenses.

Originally posted by Digitalis

The other problem is the lack of contrast for the AF system that many F/1.2 lenses suffer from. I'm sure pentax could figure out a way to get around that proclivity of fast lenses - but it will be probably be expensive.

Plus Ricoh just said in last month's interview not to expect anything fast like f/1.4 anytime soon. So their priorities are elsewhere, at least for now.

starjedi · 03-04-2014, 09:21 PM

Originally posted by DSims

Plus Ricoh just said in last month's interview not to expect anything fast like f/1.4 anytime soon. So their priorities are elsewhere, at least for now.

Yes. That's really annoying... Even Fuji now has several notable fast prime lens...

**filoxophy** · 03-04-2014, 09:51 PM

Originally posted by starjedi

Yes. That's really annoying... Even Fuji now has several notable fast prime lens...

Pentax has made it a point of pride that they have the broadest APS-C lens lineup of any manufacturer. While still true, IMHO, Fujifilm is nipping at their heels and even surpassing them in the primes department. (I'll admit to just going by numbers and specs here--I have no personal experience with them.) The 18/2, 23/1.4, 27/2.8, 35/1.4, 56/1.2...all look good on paper, whether it's the aperture, the size, the price, or all three. (The 23 and 56 are the only ones over $500 of the ones I mentioned.)

Pentax still has IBIS, weather sealing, OVF, etc etc, but I would love some Pentax primes with the above stats!

DSims · 03-04-2014, 11:56 PM

Originally posted by filoxophy

Pentax has made it a point of pride that they have the broadest APS-C lens lineup of any manufacturer. While still true, IMHO, Fujifilm is nipping at their heels and even surpassing them in the primes department. (I'll admit to just going by numbers and specs here--I have no personal experience with them.) The 18/2, 23/1.4, 27/2.8, 35/1.4, 56/1.2...all look good on paper, whether it's the aperture, the size, the price, or all three. (The 23 and 56 are the only ones over $500 of the ones I mentioned.)

Pentax still has IBIS, weather sealing, OVF, etc etc, but I would love some Pentax primes with the above stats!

They're not surpassing Pentax here, because their lineup isn't big enough or complete enough. But if you look at the quality of the photos they produce, they're outstanding.

They have at least 3 lenses here that Pentax doesn't have an answer for (although they should): 14/2.8 (Pentax 14/2.8 can't compare in quality), 23/1.4 (Pentax needs to bring back a 24/2 at the least), and 56/1.2 (Pentax was the f/1.2 pioneer when they brought out the 50/1.2 - what happened?!!). So I don't blame anyone for wanting a Fuji if they like these focal lengths. In fact, I was looking a one just today - the new camera is nice and the whole system looks really good (although it lacks long lenses).

03-01-2014, 09:10 AM	#18
DSims Veteran Member Join Date: Sep 2009 Location: Southern California Photos: Gallery \| Albums Posts: 3,236	Originally posted by Nicolas06 In case of 18-35, it is insanely sharp and as also a very fast aperture while remaining sharp. It still has a flare problem through and from the samples I have seen you doesn't have the color rendition you have typically with high end pentax glass (DA, even zooms, DA/FA ltd). Sigma choosed the 18-35 f/1.8 route instead of the 17-50 f/1.8, not only for price; a 18-50 f/1.8 would have trouble to be of same quality as of a 18-35 f/1.8. 3X is a little too much while a such short focal at the begining of the range doesn't help. 24-70 f/1.8 might be easier to design (and something similar already exist in FF with at least f/2 I think). Zoom vs Prime is not absolute. There focals that zooms handle better than others. A 50-135 or 70-200 tend to give very satisfory results. Transtandard tend to be not that good, in particular wide open, begining of the range. If the sigma change the game it is because of it's 2X range. I completely agree on all points (although I'll just take your word for it on the sharpness - haven't examined that aspect yet, but if it's anything like my Sigma 8-16 it's sharp!). No one's truly created a great 16/17/18-50/2.8 yet - how could we possibly expect a great f/1.8 lens with that range?!! Originally posted by starjedi At the prime side, Pentax for sure can deliver some fast APS-C lens such as 24mm F1.2/35mm F1.2/50mm F1.2/85 F1.2 (their size will still be smaller than FF lenses as 85 F1.2 APS-C only lens will surely be smaller than a FF 85 F1.2). The price will also be lower and at the $1000-$1500 level instead of $2000+ level. However, it is just a dream as Pentax apparently sticks with the portability on APS-C region and does not have strong motivation to challenge itself due to small market share. And as far as we know, lot of pentax prime lens are in fact ff compatible lens, which simply means that they are lazy to design as a lot of lights are wasted! As for these primes, however, it may be technically feasible. In a photography culture where people fawn over the recent Fuji X systems, Sony A7 and A7r, and the Sigma 18-35/1.8, it actually pays* to make such attention-grabbing products. So if it could easily be done, I would expect someone might be doing it! But it's not going to be Canon or Nikon, and probably not Sony. A $200 35mm f/1.8 APS-C only lens doesn't necessarily undermine FF when a FF f/1.4 version is available. But an APS-C f/1.2 lens could - especially when in theory it would cost less. And even Pentax doesn't want to go down that road now, with a FF likely coming out. So that leaves only third parties, and Sigma probably doesn't want to undermine sales of it's new 35/1.4 FF Art lens, for example. So who would do it? Last edited by DSims; 03-01-2014 at 09:42 AM.

03-02-2014, 04:44 PM - 1 Like	#26
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	The other problem is the lack of contrast for the AF system that many F/1.2 lenses suffer from. I'm sure pentax could figure out a way to get around that proclivity of fast lenses - but it will be probably be expensive. Pentax K5IIs - SMCP-K 50mm f/1.2 @ f/1.2 ISO 80 1/3200th Last edited by Digitalis; 03-03-2014 at 01:48 AM.

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03-01-2014, 05:24 AM	#16
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,650	Primes will always have, at a minimum, smaller size on a zoom. The 18-35 f1.8 may be the exception, but normally you see better sharpness at equivalent f stops, better out of focus rendering, and significantly better flare resistance. This last feature is something that, even with the best coatings, probably won't change since a fast zoom has so much more glass than the prime.

03-01-2014, 06:10 AM	#17
Nicolas06 Veteran Member Join Date: Nov 2013 Posts: 4,854	In case of 18-35, it is insanely sharp and as also a very fast aperture while remaining sharp. It still has a flare problem through and from the samples I have seen you doesn't have the color rendition you have typically with high end pentax glass (DA*, even zooms, DA/FA ltd). Sigma choosed the 18-35 f/1.8 route instead of the 17-50 f/1.8, not only for price; a 18-50 f/1.8 would have trouble to be of same quality as of a 18-35 f/1.8. 3X is a little too much while a such short focal at the begining of the range doesn't help. 24-70 f/1.8 might be easier to design (and something similar already exist in FF with at least f/2 I think). Zoom vs Prime is not absolute. There focals that zooms handle better than others. A 50-135 or 70-200 tend to give very satisfory results. Transtandard tend to be not that good, in particular wide open, begining of the range. If the sigma change the game it is because of it's 2X range.

03-01-2014, 09:35 AM	#19
VoiceOfReason Site Supporter Join Date: Jun 2010 Location: Mishawaka IN area Photos: Albums Posts: 6,124	I've never minded weight when it comes to lenses, but that may be because I'm pretty big myself at 6'2" and 255 lb. You should see my hiking kit. Small and light are not of much use if they never leave the bag.

03-01-2014, 09:11 PM	#20
starjedi Veteran Member Join Date: Dec 2013 Location: New Jersey Posts: 932 Original Poster	Originally posted by VoiceOfReason I've never minded weight when it comes to lenses, but that may be because I'm pretty big myself at 6'2" and 255 lb. You should see my hiking kit. Small and light are not of much use if they never leave the bag. As an apparently exaggerated example, let's try handhold for FA250-600mm or FA600mm :-).

03-01-2014, 09:13 PM	#21
VoiceOfReason Site Supporter Join Date: Jun 2010 Location: Mishawaka IN area Photos: Albums Posts: 6,124	If I could get the FA*250-600 I would DEFINITELY do it. I do it with my 150-500.

03-01-2014, 09:26 PM	#22
starjedi Veteran Member Join Date: Dec 2013 Location: New Jersey Posts: 932 Original Poster	Originally posted by VoiceOfReason If I could get the FA250-600 I would DEFINITELY do it. I do it with my 150-500. Haha. 150-500 is only 4.2 pound (:-)) while FA250-600 is 11.2 pound!

03-01-2014, 09:29 PM	#23
VoiceOfReason Site Supporter Join Date: Jun 2010 Location: Mishawaka IN area Photos: Albums Posts: 6,124	I'd still do it. That's one of my dream lenses.

03-02-2014, 07:03 AM - 1 Like	#24
reeftool Pentaxian Join Date: Dec 2007 Location: Upstate New York Photos: Gallery \| Albums Posts: 9,553	Originally posted by VoiceOfReason I've never minded weight when it comes to lenses, but that may be because I'm pretty big myself at 6'2" and 255 lb. You should see my hiking kit. Small and light are not of much use if they never leave the bag. I never thought much or minded the weight of my camera gear either, until recently. It happened very quickly too. Part of the problem is all those years of hiking with large and heavy packs was taking a toll on my body. I'm enjoying myself, getting exercise and thinking I'm doing something good. Maybe good for my blood pressure but I was destroying my spine, knees, and ankles. You don't think about it when you're young. I still hike, climb, and backpack and I still bring my camera but not not a lot of gear and weight is a big factor. It's not as fun as it used to be.

03-02-2014, 12:40 PM	#25
Nicolas06 Veteran Member Join Date: Nov 2013 Posts: 4,854	Some are really dreaming here. Pentax doesn't ofter anything faster than f/2.4 except for 50mm and old FA (limited or not). I don't think we will see any f/1.2 soon. The thing is they don't want to make something that could hurt their limited lenses.

03-04-2014, 03:23 AM	#27
DSims Veteran Member Join Date: Sep 2009 Location: Southern California Photos: Gallery \| Albums Posts: 3,236	Originally posted by Nicolas06 Some are really dreaming here. Pentax doesn't ofter anything faster than f/2.4 except for 50mm and old FA (limited or not). I don't think we will see any f/1.2 soon. The thing is they don't want to make something that could hurt their limited lenses. Originally posted by Digitalis The other problem is the lack of contrast for the AF system that many F/1.2 lenses suffer from. I'm sure pentax could figure out a way to get around that proclivity of fast lenses - but it will be probably be expensive. Plus Ricoh just said in last month's interview not to expect anything fast like f/1.4 anytime soon. So their priorities are elsewhere, at least for now.

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03-04-2014, 09:21 PM	#28
starjedi Veteran Member Join Date: Dec 2013 Location: New Jersey Posts: 932 Original Poster	Originally posted by DSims Plus Ricoh just said in last month's interview not to expect anything fast like f/1.4 anytime soon. So their priorities are elsewhere, at least for now. Yes. That's really annoying... Even Fuji now has several notable fast prime lens...

03-04-2014, 09:51 PM	#29
filoxophy Site Supporter Join Date: Jul 2012 Location: Albuquerque Posts: 1,132	Originally posted by starjedi Yes. That's really annoying... Even Fuji now has several notable fast prime lens... Pentax has made it a point of pride that they have the broadest APS-C lens lineup of any manufacturer. While still true, IMHO, Fujifilm is nipping at their heels and even surpassing them in the primes department. (I'll admit to just going by numbers and specs here--I have no personal experience with them.) The 18/2, 23/1.4, 27/2.8, 35/1.4, 56/1.2...all look good on paper, whether it's the aperture, the size, the price, or all three. (The 23 and 56 are the only ones over $500 of the ones I mentioned.) Pentax still has IBIS, weather sealing, OVF, etc etc, but I would love some Pentax primes with the above stats!

03-04-2014, 11:56 PM	#30
DSims Veteran Member Join Date: Sep 2009 Location: Southern California Photos: Gallery \| Albums Posts: 3,236	Originally posted by filoxophy Pentax has made it a point of pride that they have the broadest APS-C lens lineup of any manufacturer. While still true, IMHO, Fujifilm is nipping at their heels and even surpassing them in the primes department. (I'll admit to just going by numbers and specs here--I have no personal experience with them.) The 18/2, 23/1.4, 27/2.8, 35/1.4, 56/1.2...all look good on paper, whether it's the aperture, the size, the price, or all three. (The 23 and 56 are the only ones over $500 of the ones I mentioned.) Pentax still has IBIS, weather sealing, OVF, etc etc, but I would love some Pentax primes with the above stats! They're not surpassing Pentax here, because their lineup isn't big enough or complete enough. But if you look at the quality of the photos they produce, they're outstanding. They have at least 3 lenses here that Pentax doesn't have an answer for (although they should): 14/2.8 (Pentax 14/2.8 can't compare in quality), 23/1.4 (Pentax needs to bring back a 24/2 at the least), and 56/1.2 (Pentax was the f/1.2 pioneer when they brought out the 50/1.2 - what happened?!!). So I don't blame anyone for wanting a Fuji if they like these focal lengths. In fact, I was looking a one just today - the new camera is nice and the whole system looks really good (although it lacks long lenses).