Adapter to use 3rd party lenses on Pentax (Sony)

Dericali · 12-21-2021, 04:14 AM

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Has anyone found an adapter to use Sony lenses on a Pentax body?

I'd like to use the Laowa 15mm shift lens on Pentax, since although I have a Sony A7III, the experience of using this for real estate/architecture bracketed shots is atrocious, so I want to continue using my Pentax K1 body.

BarneyL · 12-21-2021, 04:26 AM

You cannot use lenses for mirrorless on DSLR due to way smaller distance between mount and the sensor.

biz-engineer · 12-21-2021, 05:14 AM

Looks like it's a Sony problem. How about to ask Sony for support about it?

**pepperberry farm** · 12-21-2021, 05:28 AM

Originally posted by BarneyL

You cannot use lenses for mirrorless on DSLR due to way smaller distance between mount and the sensor.

you can, but the adapter will have an additional lens built-in for proper registration distance....

traditionally, this is not a good idea, as it can potentially further degrade the image....

**BigMackCam** · 12-21-2021, 05:55 AM

Originally posted by Dericali

Has anyone found an adapter to use Sony lenses on a Pentax body?

I'd like to use the Laowa 15mm shift lens on Pentax, since although I have a Sony A7III, the experience of using this for real estate/architecture bracketed shots is atrocious, so I want to continue using my Pentax K1 body.

As others have suggested, the flange focal distance (distance between the mount and sensor) on Sony E-mount is shorter than K-mount. As such, you can't adapt lenses from the former to the latter without putting glass in between them. I've not heard of an E-mount to K-mount adapter, but if one exists it will almost-certainly introduce a reduction in optical performance, as well as resulting in a longer focal length / narrower field of view than you benefit from on its native platform.

**UncleVanya** · 12-21-2021, 06:12 AM - **2 Likes**

Sell the lens. Buy the k mount version. There’s no way to do what you want available that I know of. The majority of Sony lenses are focus by wire and electronic aperture. These on top of the relative differences in registration distances make adapters impractical. Even with manual focus and manual aperture lenses the adapter would have teleconveter elements to adapt the flange distances as others mentioned.

ChristianRock · 12-21-2021, 08:18 AM

Yes buying the K-mount version is the way to go.

**Bob 256** · 12-21-2021, 09:10 AM

Note the OP is talking about a shift lens. Does Pentax (or anyone else) make such a critter in the 15mm range with a K mount? The OP may need to have one fabricated. And yes, to extend the focal length (which is needed of a Sony lens to reach the sensor), a weak negative lens is introduced in any adapter of that type, which definitely bodes poorly for IQ and color aberrations.

ADDENDA: I'll answer my own question. Here's one from Laowa - don't know what the performance or IQ is for this lens.

https://www.ebay.com/itm/284246420792?chn=ps&norover=1&mkevt=1&mkrid=711-213...ceffe0519197d5

Keep answering my own replies:

https://www.pentaxforums.com/userreviews/venus-laowa-15mm-f4-11-macro.html

**luftfluss** · 12-21-2021, 10:58 AM

Originally posted by Bob 256

Keep answering my own replies:

Venus Optics Laowa 15mm F4 1:1 Macro Lens Reviews - Venus Laowa Lenses - Pentax Lens Review Database

Hmmmm...

Quote:

A full frame ultra-wide lens that doubles as a true macro lens with 1:1 magnification. The lens is quite unique in that it shifts +/-6mm for perspective correction. The shift function only works when the lens is used for the APS-C format. On FF shifting will produce dark corners.

**UncleVanya** · 12-21-2021, 11:25 AM

There are TWO Laowa 15mm shift lenses. Both appear to be available to both e Mount and k mount users.

https://www.bhphotovideo.com/c/product/1165603-REG/venus_optics_laowa_15mm_f...981&

https://www.bhphotovideo.com/c/product/1634987-REG/venus_optics_ve1545pk_lao...981&

The former is limited to apsc and has a very small shift range. This f4.5 version has a much larger image circle that makes it more suitable for full frame use.

Dericali · 12-21-2021, 11:55 AM

Yes it's the Laowa 15mm f4.5 shift for full frame.

I currently have the 15-30mm Pentax (Tamron) zoom, which - coupled with the Pentax K1's ability to physically shift the sensor - is pretty solid for most shoots, except when shooting 4 storey buildings (or higher) in city areas where distance to building is often quite limited.

I'm not aware of any wider Pentax lens options for FF, probably I will just have to continue using two bodies/systems.

**BigMackCam** · 12-21-2021, 12:00 PM

Originally posted by Dericali

I'm not aware of any wider Pentax lens options for FF, probably I will just have to continue using two bodies/systems.

Samyang / Rokinon 14mm f/2.8 AS IF UMC, perhaps? I'm not sure if it's still available new, but I see occasional used copies...

**UncleVanya** · 12-21-2021, 12:13 PM

Originally posted by Dericali

I'm not aware of any wider Pentax lens options for FF, probably I will just have to continue using two bodies/systems.

Assuming you don’t want a fisheye, there are still a few wider such as:

Venus Optics Laowa 12mm F2.8 Zero-D Lens Reviews - Venus Laowa Lenses - Pentax Lens Review Database

Irix 11mm F4 Blackstone Lens Reviews - Irix Lenses - Pentax Lens Review Database

But once shift is included the Laowa 15 f4.5 is probably “wider” in effect. Since the lens is available on Pentax K mount and Sony you could collapse this to a single system if this is the only sticking point.

What is the failure to meet expectations for you with this lens on Sony?

stevebrot · 12-21-2021, 05:29 PM - **1 Like**

Originally posted by BigMackCam

Samyang / Rokinon 14mm f/2.8 AS IF UMC, perhaps? I'm not sure if it's still available new, but I see occasional used copies...

Buying new is no problem on this side of the Atlantic. It is also current product with Samyang, though only sold under the Samyang and Rokinon brand names. I bought mine on Amazon Prime and they will currently sell me another for $299 USD. It is also available at B&H at that price and at Adorama for $339 USD.

Steve

yusuf · 12-21-2021, 08:58 PM

you can't without an optical adapter but curious, which lens do you want to use?

12-21-2021, 04:14 AM	#1
Dericali Senior Member Join Date: Jul 2016 Location: Berlin Posts: 298	Adapter to use 3rd party lenses on Pentax (Sony) 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. Has anyone found an adapter to use Sony lenses on a Pentax body? I'd like to use the Laowa 15mm shift lens on Pentax, since although I have a Sony A7III, the experience of using this for real estate/architecture bracketed shots is atrocious, so I want to continue using my Pentax K1 body.

12-21-2021, 09:10 AM	#8
Bob 256 Site Supporter Join Date: Jun 2008 Location: Idaho Photos: Gallery Posts: 2,375	Note the OP is talking about a shift lens. Does Pentax (or anyone else) make such a critter in the 15mm range with a K mount? The OP may need to have one fabricated. And yes, to extend the focal length (which is needed of a Sony lens to reach the sensor), a weak negative lens is introduced in any adapter of that type, which definitely bodes poorly for IQ and color aberrations. ADDENDA: I'll answer my own question. Here's one from Laowa - don't know what the performance or IQ is for this lens. https://www.ebay.com/itm/284246420792?chn=ps&norover=1&mkevt=1&mkrid=711-213...ceffe0519197d5 Keep answering my own replies: https://www.pentaxforums.com/userreviews/venus-laowa-15mm-f4-11-macro.html Last edited by Bob 256; 12-21-2021 at 09:27 AM.

12-21-2021, 12:13 PM	#13
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,403	Originally posted by Dericali I'm not aware of any wider Pentax lens options for FF, probably I will just have to continue using two bodies/systems. Assuming you don’t want a fisheye, there are still a few wider such as: Venus Optics Laowa 12mm F2.8 Zero-D Lens Reviews - Venus Laowa Lenses - Pentax Lens Review Database Irix 11mm F4 Blackstone Lens Reviews - Irix Lenses - Pentax Lens Review Database But once shift is included the Laowa 15 f4.5 is probably “wider” in effect. Since the lens is available on Pentax K mount and Sony you could collapse this to a single system if this is the only sticking point. What is the failure to meet expectations for you with this lens on Sony? Last edited by UncleVanya; 12-21-2021 at 09:01 PM.

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12-21-2021, 04:26 AM	#2
BarneyL Pentaxian Join Date: Feb 2017 Posts: 899	You cannot use lenses for mirrorless on DSLR due to way smaller distance between mount and the sensor.

12-21-2021, 05:14 AM	#3
biz-engineer Pentaxian Join Date: Feb 2015 Photos: Gallery Posts: 12,232	Looks like it's a Sony problem. How about to ask Sony for support about it?

12-21-2021, 05:28 AM	#4
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,678	Originally posted by BarneyL You cannot use lenses for mirrorless on DSLR due to way smaller distance between mount and the sensor. you can, but the adapter will have an additional lens built-in for proper registration distance.... traditionally, this is not a good idea, as it can potentially further degrade the image....

12-21-2021, 05:55 AM	#5
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,673	Originally posted by Dericali Has anyone found an adapter to use Sony lenses on a Pentax body? I'd like to use the Laowa 15mm shift lens on Pentax, since although I have a Sony A7III, the experience of using this for real estate/architecture bracketed shots is atrocious, so I want to continue using my Pentax K1 body. As others have suggested, the flange focal distance (distance between the mount and sensor) on Sony E-mount is shorter than K-mount. As such, you can't adapt lenses from the former to the latter without putting glass in between them. I've not heard of an E-mount to K-mount adapter, but if one exists it will almost-certainly introduce a reduction in optical performance, as well as resulting in a longer focal length / narrower field of view than you benefit from on its native platform.

12-21-2021, 06:12 AM - 2 Likes	#6
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,403	Sell the lens. Buy the k mount version. There’s no way to do what you want available that I know of. The majority of Sony lenses are focus by wire and electronic aperture. These on top of the relative differences in registration distances make adapters impractical. Even with manual focus and manual aperture lenses the adapter would have teleconveter elements to adapt the flange distances as others mentioned.

12-21-2021, 08:18 AM	#7
ChristianRock Pentaxian Join Date: Jul 2013 Location: People's Republic of America Photos: Gallery \| Albums Posts: 9,910	Yes buying the K-mount version is the way to go.

12-21-2021, 10:58 AM	#9
luftfluss Site Supporter Join Date: Jun 2011 Location: NJ Photos: Gallery \| Albums Posts: 11,619	Originally posted by Bob 256 Keep answering my own replies: Venus Optics Laowa 15mm F4 1:1 Macro Lens Reviews - Venus Laowa Lenses - Pentax Lens Review Database Hmmmm... Quote: A full frame ultra-wide lens that doubles as a true macro lens with 1:1 magnification. The lens is quite unique in that it shifts +/-6mm for perspective correction. The shift function only works when the lens is used for the APS-C format. On FF shifting will produce dark corners.

12-21-2021, 11:25 AM	#10
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,403	There are TWO Laowa 15mm shift lenses. Both appear to be available to both e Mount and k mount users. https://www.bhphotovideo.com/c/product/1165603-REG/venus_optics_laowa_15mm_f...981& https://www.bhphotovideo.com/c/product/1634987-REG/venus_optics_ve1545pk_lao...981& The former is limited to apsc and has a very small shift range. This f4.5 version has a much larger image circle that makes it more suitable for full frame use.

12-21-2021, 11:55 AM	#11
Dericali Senior Member Join Date: Jul 2016 Location: Berlin Posts: 298 Original Poster	Yes it's the Laowa 15mm f4.5 shift for full frame. I currently have the 15-30mm Pentax (Tamron) zoom, which - coupled with the Pentax K1's ability to physically shift the sensor - is pretty solid for most shoots, except when shooting 4 storey buildings (or higher) in city areas where distance to building is often quite limited. I'm not aware of any wider Pentax lens options for FF, probably I will just have to continue using two bodies/systems.

12-21-2021, 12:00 PM	#12
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,673	Originally posted by Dericali I'm not aware of any wider Pentax lens options for FF, probably I will just have to continue using two bodies/systems. Samyang / Rokinon 14mm f/2.8 AS IF UMC, perhaps? I'm not sure if it's still available new, but I see occasional used copies...

12-21-2021, 05:29 PM - 1 Like	#14
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by BigMackCam Samyang / Rokinon 14mm f/2.8 AS IF UMC, perhaps? I'm not sure if it's still available new, but I see occasional used copies... Buying new is no problem on this side of the Atlantic. It is also current product with Samyang, though only sold under the Samyang and Rokinon brand names. I bought mine on Amazon Prime and they will currently sell me another for $299 USD. It is also available at B&H at that price and at Adorama for $339 USD. Steve

12-21-2021, 08:58 PM	#15
yusuf Pentaxian Join Date: Nov 2008 Location: Palo Alto, CA Photos: Gallery Posts: 2,497	you can't without an optical adapter but curious, which lens do you want to use?