M 20 f4; prices? Alternatives?

**jatrax** · 07-09-2018, 12:10 PM - **1 Like**

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Originally posted by Simen1

I will be disappointed if its huge.

Prepare for disappointment. I'm betting on huge.

**pres589** · 07-09-2018, 12:15 PM - **1 Like**

I need a lens with an aperture ring so anything modern from Pentax isn't going to work for me. None of the 3rd party options seem interested in "small". I do think there's something weird about folks buying, or at least trying to sell, M 20's for $300, $400 etc US dollars online. A and FA 20's are being listed for $600+.

The MIR 20 seems interesting and maybe for an M42 kit I would consider it. It doesn't seem *that* much smaller than the Tamron 17.

Nikon 20, converted, seems interesting. I kind of wonder if I could butcher a mount off of a junk lens and do my own conversion. But the pricing doesn't seem much better for the amount of work required. Doing a mechanical drawing of the Tamron lens hood I have and basically just making a copy that is just filter threads for some other hood to screw onto has a certain ring to it...

I think I really just want the M 20 and should wait for a good deal here or elsewhere to pop up.

**c.a.m** · 07-09-2018, 12:22 PM - **1 Like**

@pres589, would an RMC Tokina 17/3.5 be of interest?

While it's not tiny like the M 20/4 (300 g vs. 150 g), it's not huge. I had one for a while and found it to be easy to handle in the field. It's very sharp in the centre and decent at the edges and corners.

There is one listed in the PF Marketplace (not mine, and no affiliation).

- Craig

**pres589** · 07-09-2018, 12:45 PM

I believe the Tamron 17 I have now is a better performer. Just, you know, they didn't put filter threads directly on the lens body for some reason... I've checked comparisons of these two lenses and I'm probably better off sticking with what I've got if I don't end up with an M 20.

bm75 · 07-09-2018, 12:46 PM

Any modern lens will be much bigger than original m20. compared to Nikon 20 f\1,8 my M20 it's one third in size. So people having a M20 perhaps aren't going to sell their copies, as they can be perfectly aimed to be used with MILCs or simply kept in the bag with other vintage lenses .

**c.a.m** · 07-09-2018, 12:51 PM

Originally posted by pres589

I believe the Tamron 17 I have now is a better performer.

Ahh, fair point. I thought I had read the earlier posts thoroughly, but missed your statement about the Tamron 17.

My earlier research led me to conclude that the Tamron and Tokina are similar in performance, with each having relative strengths and weaknesses. I agree that you wouldn't gain much with the Tokina.

ACG · 07-09-2018, 01:30 PM - **3 Likes**

I have both the m20 and k20. I have reviewed both on this forum.

If you are using mirror less, the sensor stack thickness reduces the sharpness of the peripheral 10%.

The m20 is truly pocketable and does produce lovely colours, vibrancy and contrast. Very sharp from f5.6 in centre two thirds.

The k20 is a lovely old lens. Beautiful handling and long focus throw. Wins on iq. It is my favourite ultra wide angle lens.

My favourite three lenses for the a7r3 are the k20f4, k28f3.5 and m50 1.7

The modern auto focus lenses stay at home in their boxes.

With legacy lenses you can produce images with their own character and therefore stand out from the “modern” crowd.

**pres589** · 07-09-2018, 01:40 PM - **1 Like**

This is for a film kit. I don't see mirrorless in my future. The camera and a mounted lens may be spending some amount of time in a motorcycle tank bag so I want something small/thin. I really want the whole kit to fit in a bag the size of my ThinkTank Mirrorless Mover 30i. Something smaller than that would be just fine with me. This includes a mini-tripod and a couple rolls of film.

I just thought about what it would be like to try and hold my Ricoh XR-7 or a K1000 to my eye while wearing a motorcycle helmet....

In any case, yeah, need a small ultra-wide.

Simen1 · 07-09-2018, 03:33 PM

Originally posted by jatrax

Prepare for disappointment. I'm betting on huge.

I believe its roadmap neighbor "Large Aperture Wide-Angle Single Focus lens" will be the huge one. Probably 24mm f/1,4 or close to that.

I believe the ultra-wide angle will be smaller and have f/2,8 or smaller aperture.

**kiwi_jono** · 07-09-2018, 04:54 PM - **1 Like**

I had the same problems with my K-1. The DFA15-30 is a bit out of my budget and rather big and heavy for what I want (something I can casually carry around in my bag).

I really wanted something like a FA20 but they are fairly rare and are snapped up at (now) relatively high prices. I tried getting a Samyang 14mm but it was badly decentred and being in NZ did not want to persist with shipping multiple copies to get one that was good (and reasonable price).
Over the last couple of years I ended up with the following second hand lenses:
1. Sigma EX 20mm f1.8
2. Pentax K 17mm f4 fisheye
3. Sigma EX 15-30 f3.5-4.5 (very recent purchase)

The Sigma 20 was relatively cheap and is a lot of fun. It doesn't have perfect sharpness (its soft in one corner - which is pretty common for these Sigma lenses) but its still possible to get a sharp image across the frame stopped down and the fast aperture and close minimum focus distance makes it a great lens for creative shots. It is a little bigger than I would like but a lot smaller than the DFA15-30 (and half the weight!).

I also like the K17mm fisheye. Sharpness is pretty good (although not tack sharp), CA a bit high but its a very compact lens and perfect to carry when I'm travelling light.

Sigma 15-30. Have not written a review yet as I'm still testing it. However so far I can say its big (not something I would always carry around) - but I knew that going in. Good build, case, useful focal range but so far I am underwhelmed by its sharpness, contrast and flare control. I'm still need to do some more testing to eliminate all other factors but so far I'm a bit disappointed.

tvdtvdtvd · 07-09-2018, 05:41 PM - **1 Like**

Originally posted by Simen1

I believe that is what the "Ultra wide-angle single focus lens" are in the roadmap. I will be disappointed if its huge.

I too am hoping for a petite 20/4 as the roadmapped UWA. That will certainly earn my nickels. But a hyper corrected, 17 element 20/1.8 will only
be admired from afar, not just for its inevitable price but very much for its size. Save the Sigma beater for the forthcoming 85mm and the Large
Aperture Wide Angle, (a fast 28?). Ricoh, are you listening?

**jatrax** · 07-09-2018, 05:55 PM

Originally posted by tvdtvdtvd

But a hyper corrected, 17 element 20/1.8 will onlybe admired from afar

With the increased interest in astrophotography such a lens might get more interest than we think. Provided it shows some advantage over the already popular Samyang ones.

**kernos** · 07-09-2018, 06:06 PM

Well there is the Russian version of the Flektagon, the Mir 20mm F3.5 in m42 I don't have it, but it seems to be pretty well thought of. Also, it just looks amazing on a camera, this one is adapted to a Nikon.

**UncleVanya** · 07-09-2018, 07:07 PM

Originally posted by kernos

Well there is the Russian version of the Flektagon, the Mir 20mm F3.5 in m42 I don't have it, but it seems to be pretty well thought of. Also, it just looks amazing on a camera, this one is adapted to a Nikon.

Several posts mentioned it but the OP is looking for small and light and that lens while lovely looking doesn't seem to fit the bill. They already have a 17mm f/4 that is good but not what they want.

tvdtvdtvd · 07-09-2018, 08:44 PM

Originally posted by jatrax

With the increased interest in astrophotography such a lens might get more interest than we think. Provided it shows some advantage over the already popular Samyang ones.

True enough; I meant it would be admired from afar by >me<, not necessarily everyone. Nonetheless, this thread
proves there is demand for a modestly fast, petite 20mm. I think we can agree there's likely room for both, provided
Ricoh can find the R&D time.....

07-09-2018, 06:06 PM	#28
kernos Site Supporter Join Date: Feb 2013 Posts: 456	Well there is the Russian version of the Flektagon, the Mir 20mm F3.5 in m42 I don't have it, but it seems to be pretty well thought of. Also, it just looks amazing on a camera, this one is adapted to a Nikon. Last edited by kernos; 07-09-2018 at 06:07 PM. Reason: clarification

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07-09-2018, 12:10 PM - 1 Like	#16
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. Originally posted by Simen1 I will be disappointed if its huge. Prepare for disappointment. I'm betting on huge.

07-09-2018, 12:15 PM - 1 Like	#17
pres589 Site Supporter Join Date: Jan 2014 Location: Wichita, KS Photos: Albums Posts: 4,529 Original Poster	I need a lens with an aperture ring so anything modern from Pentax isn't going to work for me. None of the 3rd party options seem interested in "small". I do think there's something weird about folks buying, or at least trying to sell, M 20's for $300, $400 etc US dollars online. A and FA 20's are being listed for $600+. The MIR 20 seems interesting and maybe for an M42 kit I would consider it. It doesn't seem that much smaller than the Tamron 17. Nikon 20, converted, seems interesting. I kind of wonder if I could butcher a mount off of a junk lens and do my own conversion. But the pricing doesn't seem much better for the amount of work required. Doing a mechanical drawing of the Tamron lens hood I have and basically just making a copy that is just filter threads for some other hood to screw onto has a certain ring to it... I think I really just want the M 20 and should wait for a good deal here or elsewhere to pop up.

07-09-2018, 12:22 PM - 1 Like	#18
c.a.m Site Supporter Join Date: Jan 2013 Location: Ottawa, Canada Photos: Gallery \| Albums Posts: 4,188	@pres589, would an RMC Tokina 17/3.5 be of interest? While it's not tiny like the M 20/4 (300 g vs. 150 g), it's not huge. I had one for a while and found it to be easy to handle in the field. It's very sharp in the centre and decent at the edges and corners. There is one listed in the PF Marketplace (not mine, and no affiliation). - Craig

07-09-2018, 12:45 PM	#19
pres589 Site Supporter Join Date: Jan 2014 Location: Wichita, KS Photos: Albums Posts: 4,529 Original Poster	I believe the Tamron 17 I have now is a better performer. Just, you know, they didn't put filter threads directly on the lens body for some reason... I've checked comparisons of these two lenses and I'm probably better off sticking with what I've got if I don't end up with an M 20.

07-09-2018, 12:46 PM	#20
bm75 Veteran Member Join Date: Aug 2014 Location: Italia Photos: Albums Posts: 354	Any modern lens will be much bigger than original m20. compared to Nikon 20 f\1,8 my M20 it's one third in size. So people having a M20 perhaps aren't going to sell their copies, as they can be perfectly aimed to be used with MILCs or simply kept in the bag with other vintage lenses .

07-09-2018, 12:51 PM	#21
c.a.m Site Supporter Join Date: Jan 2013 Location: Ottawa, Canada Photos: Gallery \| Albums Posts: 4,188	Originally posted by pres589 I believe the Tamron 17 I have now is a better performer. Ahh, fair point. I thought I had read the earlier posts thoroughly, but missed your statement about the Tamron 17. My earlier research led me to conclude that the Tamron and Tokina are similar in performance, with each having relative strengths and weaknesses. I agree that you wouldn't gain much with the Tokina.

07-09-2018, 01:30 PM - 3 Likes	#22
ACG Forum Member Join Date: Apr 2014 Photos: Gallery \| Albums Posts: 61	I have both the m20 and k20. I have reviewed both on this forum. If you are using mirror less, the sensor stack thickness reduces the sharpness of the peripheral 10%. The m20 is truly pocketable and does produce lovely colours, vibrancy and contrast. Very sharp from f5.6 in centre two thirds. The k20 is a lovely old lens. Beautiful handling and long focus throw. Wins on iq. It is my favourite ultra wide angle lens. My favourite three lenses for the a7r3 are the k20f4, k28f3.5 and m50 1.7 The modern auto focus lenses stay at home in their boxes. With legacy lenses you can produce images with their own character and therefore stand out from the “modern” crowd.

07-09-2018, 01:40 PM - 1 Like	#23
pres589 Site Supporter Join Date: Jan 2014 Location: Wichita, KS Photos: Albums Posts: 4,529 Original Poster	This is for a film kit. I don't see mirrorless in my future. The camera and a mounted lens may be spending some amount of time in a motorcycle tank bag so I want something small/thin. I really want the whole kit to fit in a bag the size of my ThinkTank Mirrorless Mover 30i. Something smaller than that would be just fine with me. This includes a mini-tripod and a couple rolls of film. I just thought about what it would be like to try and hold my Ricoh XR-7 or a K1000 to my eye while wearing a motorcycle helmet.... In any case, yeah, need a small ultra-wide.

07-09-2018, 03:33 PM	#24
Simen1 Veteran Member Join Date: Jul 2009 Location: Tromsø, Norway Photos: Albums Posts: 1,031	Originally posted by jatrax Prepare for disappointment. I'm betting on huge. I believe its roadmap neighbor "Large Aperture Wide-Angle Single Focus lens" will be the huge one. Probably 24mm f/1,4 or close to that. I believe the ultra-wide angle will be smaller and have f/2,8 or smaller aperture.

07-09-2018, 04:54 PM - 1 Like	#25
kiwi_jono Loyal Site Supporter Join Date: Dec 2009 Location: Christchurch, New Zealand Photos: Gallery \| Albums Posts: 2,437	I had the same problems with my K-1. The DFA15-30 is a bit out of my budget and rather big and heavy for what I want (something I can casually carry around in my bag). I really wanted something like a FA20 but they are fairly rare and are snapped up at (now) relatively high prices. I tried getting a Samyang 14mm but it was badly decentred and being in NZ did not want to persist with shipping multiple copies to get one that was good (and reasonable price). Over the last couple of years I ended up with the following second hand lenses: 1. Sigma EX 20mm f1.8 2. Pentax K 17mm f4 fisheye 3. Sigma EX 15-30 f3.5-4.5 (very recent purchase) The Sigma 20 was relatively cheap and is a lot of fun. It doesn't have perfect sharpness (its soft in one corner - which is pretty common for these Sigma lenses) but its still possible to get a sharp image across the frame stopped down and the fast aperture and close minimum focus distance makes it a great lens for creative shots. It is a little bigger than I would like but a lot smaller than the DFA15-30 (and half the weight!). I also like the K17mm fisheye. Sharpness is pretty good (although not tack sharp), CA a bit high but its a very compact lens and perfect to carry when I'm travelling light. Sigma 15-30. Have not written a review yet as I'm still testing it. However so far I can say its big (not something I would always carry around) - but I knew that going in. Good build, case, useful focal range but so far I am underwhelmed by its sharpness, contrast and flare control. I'm still need to do some more testing to eliminate all other factors but so far I'm a bit disappointed.

07-09-2018, 05:41 PM - 1 Like	#26
tvdtvdtvd Veteran Member Join Date: Jan 2010 Posts: 1,665	Originally posted by Simen1 I believe that is what the "Ultra wide-angle single focus lens" are in the roadmap. I will be disappointed if its huge. I too am hoping for a petite 20/4 as the roadmapped UWA. That will certainly earn my nickels. But a hyper corrected, 17 element 20/1.8 will only be admired from afar, not just for its inevitable price but very much for its size. Save the Sigma beater for the forthcoming 85mm and the Large Aperture Wide Angle, (a fast 28?). Ricoh, are you listening?

07-09-2018, 05:55 PM	#27
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by tvdtvdtvd But a hyper corrected, 17 element 20/1.8 will onlybe admired from afar With the increased interest in astrophotography such a lens might get more interest than we think. Provided it shows some advantage over the already popular Samyang ones.

07-09-2018, 07:07 PM	#29
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,398	Originally posted by kernos Well there is the Russian version of the Flektagon, the Mir 20mm F3.5 in m42 I don't have it, but it seems to be pretty well thought of. Also, it just looks amazing on a camera, this one is adapted to a Nikon. Several posts mentioned it but the OP is looking for small and light and that lens while lovely looking doesn't seem to fit the bill. They already have a 17mm f/4 that is good but not what they want.

07-09-2018, 08:44 PM	#30
tvdtvdtvd Veteran Member Join Date: Jan 2010 Posts: 1,665	Originally posted by jatrax With the increased interest in astrophotography such a lens might get more interest than we think. Provided it shows some advantage over the already popular Samyang ones. True enough; I meant it would be admired from afar by >me<, not necessarily everyone. Nonetheless, this thread proves there is demand for a modestly fast, petite 20mm. I think we can agree there's likely room for both, provided Ricoh can find the R&D time.....

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