Rokinon 8mm f/3.5

Blacknight659 · 09-15-2015, 11:34 AM

Originally posted by pathdoc

Pray tell, how is this particular bit of sleight-of-hand performed?

Yes... How is this done? Duck tape adapter ring?

**UncleVanya** · 09-15-2015, 11:50 AM

Originally posted by Blacknight659

Yes... How is this done? Duck tape adapter ring?

Any Nikon lens can be mounted on a Pentax - just not super secure without any modification at all. There are several threads about it. The lens bayonet doesn't turn far - maybe 1/8 of a rotation. And the lock pin doesn't seat unless you drill the Nikon's to fit that. Depending on how deeply it fits Infinity focus may be an issue since the Nikon mount is longer slightly but a shim can help with that.

I'll add some pictures of a Nikon 50mm f/2 on my K3 and a picture I took using it in just a few minutes.

Uncropped SOOC - focused on the surface reflection on the iPhone using Focus Confirmation - shot in Av mode open for focus and then turned ring for stopped down shot - ISO 3200, 1/125s @ f/5.6 I think.

pathdoc · 09-15-2015, 11:52 AM

I am further assuming that regarding focus and stop-down, one is firmly in Takumar territory, as it were.

**UncleVanya** · 09-15-2015, 12:00 PM

Originally posted by pathdoc

I am further assuming that regarding focus and stop-down, one is firmly in Takumar territory, as it were.

Yes. It behaves like a Takumar set on Manual aperture. I had to intentionally add a -2 EV bias before the exposure came out the way I liked it. I have seen just as bad on M lenses and Takumars at times. ISO was too high - I was in a hurry.

pathdoc · 09-15-2015, 12:18 PM - **1 Like**

I can live with that, especially with any camera that has aperture priority. I found relevant threads and a website of a Singaporean chap selling a replacement mount that's compatible with most things, but I'm not sure I'd dare to go there on anything other than a K or M-mount film camera or a very old digital that I was willing to risk ruining. Certainly not my only DSLR. Nikon lenses are described as focusing "past infinity", but surely this is far less of a problem than not being able to get there in the first place! TO INFINITY AND BEYOND!! (Yes, I am a parent and I have consequently seen the Toy Story films far too many times.)

**UncleVanya** · 09-15-2015, 12:26 PM

Originally posted by pathdoc

I can live with that, especially with any camera that has aperture priority. I found relevant threads and a website of a Singaporean chap selling a replacement mount that's compatible with most things, but I'm not sure I'd dare to go there on anything other than a K or M-mount film camera or a very old digital that I was willing to risk ruining. Certainly not my only DSLR. Nikon lenses are described as focusing "past infinity", but surely this is far less of a problem than not being able to get there in the first place! TO INFINITY AND BEYOND!! (Yes, I am a parent and I have consequently seen the Toy Story films far too many times.)

I have very limited experience doing this. I first saw it in threads on the forum. I would caution you that the lens isn't really secure, the adaptist mount replacement solution is more secure.

pathdoc · 09-15-2015, 01:01 PM

I consider it an emergency solution only.

**UncleVanya** · 09-15-2015, 01:43 PM

Originally posted by pathdoc

I consider it an emergency solution only.

I tend to agree. However another user modified the Nikons he had by adding a shim with the lock cutout and in that case it seemed to fit and lock - I have not tried it. YMMV. But in a pinch - It can be done.

Not sure how many photography emergencies I will ever have to make me resort to this...

**THoog** · 09-15-2015, 02:04 PM

Originally posted by UncleVanya

photography emergencies

I think this sort of emergency would be of the "severe attack of LBA" variety.

**UncleVanya** · 09-15-2015, 02:05 PM

Originally posted by THoog

I think this sort of emergency would be of the "severe attack of LBA" variety.

Yes... that seems about right. "If only I had a 105 f/2.5 Pentax... wait Nikon made those!"

---------- Post added 09-15-15 at 05:06 PM ----------

Originally posted by THoog

I think this sort of emergency would be of the "severe attack of LBA" variety.

Yes... that seems about right. "If only I had a 105 f/2.5 Pentax... wait Nikon made those!" But to bring this back to the subject - I did enjoy using a 7.5mm Nikon Fisheye that required the mirror be locked up to use. It was fun - you used a viewfinder with it since there was no way to see the image otherwise until you developed the film.

**THoog** · 09-15-2015, 02:19 PM

Originally posted by UncleVanya

Yes... that seems about right. "If only I had a 105 f/2.5 Pentax... wait Nikon made those!"

Exactly. I've had brief LBA attacks like that, but have (mostly) been able to fight it off with medication and blows to the head. People just don't understand what a terrible, terrible disease it is.

One of my favorite fishy toys is an old Kenko 180-degree adapter that does a full-circle FE on a 50mm (FF) or 35mm (APSC) lens. It's the one piece of gear that has ever caused a stranger to walk up to me and ask "what is that lens?"

Driline · 09-15-2015, 02:47 PM

Originally posted by kiwi_jono

Ok I will play too.

Its a fun lens for sure.

Wow. That lens also puts the steering wheel on the wrong side of the car too!

09-15-2015, 11:50 AM	#47
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Originally posted by Blacknight659 Yes... How is this done? Duck tape adapter ring? Any Nikon lens can be mounted on a Pentax - just not super secure without any modification at all. There are several threads about it. The lens bayonet doesn't turn far - maybe 1/8 of a rotation. And the lock pin doesn't seat unless you drill the Nikon's to fit that. Depending on how deeply it fits Infinity focus may be an issue since the Nikon mount is longer slightly but a shim can help with that. I'll add some pictures of a Nikon 50mm f/2 on my K3 and a picture I took using it in just a few minutes. Uncropped SOOC - focused on the surface reflection on the iPhone using Focus Confirmation - shot in Av mode open for focus and then turned ring for stopped down shot - ISO 3200, 1/125s @ f/5.6 I think. Last edited by UncleVanya; 09-15-2015 at 12:01 PM.

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09-15-2015, 11:34 AM	#46
Blacknight659 Veteran Member Join Date: Aug 2013 Photos: Gallery \| Albums Posts: 731	Originally posted by pathdoc Pray tell, how is this particular bit of sleight-of-hand performed? Yes... How is this done? Duck tape adapter ring?

09-15-2015, 11:52 AM	#48
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	I am further assuming that regarding focus and stop-down, one is firmly in Takumar territory, as it were.

09-15-2015, 12:00 PM	#49
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Originally posted by pathdoc I am further assuming that regarding focus and stop-down, one is firmly in Takumar territory, as it were. Yes. It behaves like a Takumar set on Manual aperture. I had to intentionally add a -2 EV bias before the exposure came out the way I liked it. I have seen just as bad on M lenses and Takumars at times. ISO was too high - I was in a hurry.

09-15-2015, 12:18 PM - 1 Like	#50
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	I can live with that, especially with any camera that has aperture priority. I found relevant threads and a website of a Singaporean chap selling a replacement mount that's compatible with most things, but I'm not sure I'd dare to go there on anything other than a K or M-mount film camera or a very old digital that I was willing to risk ruining. Certainly not my only DSLR. Nikon lenses are described as focusing "past infinity", but surely this is far less of a problem than not being able to get there in the first place! TO INFINITY AND BEYOND!! (Yes, I am a parent and I have consequently seen the Toy Story films far too many times.)

09-15-2015, 12:26 PM	#51
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Originally posted by pathdoc I can live with that, especially with any camera that has aperture priority. I found relevant threads and a website of a Singaporean chap selling a replacement mount that's compatible with most things, but I'm not sure I'd dare to go there on anything other than a K or M-mount film camera or a very old digital that I was willing to risk ruining. Certainly not my only DSLR. Nikon lenses are described as focusing "past infinity", but surely this is far less of a problem than not being able to get there in the first place! TO INFINITY AND BEYOND!! (Yes, I am a parent and I have consequently seen the Toy Story films far too many times.) I have very limited experience doing this. I first saw it in threads on the forum. I would caution you that the lens isn't really secure, the adaptist mount replacement solution is more secure.

09-15-2015, 01:01 PM	#52
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	I consider it an emergency solution only.

09-15-2015, 01:43 PM	#53
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Originally posted by pathdoc I consider it an emergency solution only. I tend to agree. However another user modified the Nikons he had by adding a shim with the lock cutout and in that case it seemed to fit and lock - I have not tried it. YMMV. But in a pinch - It can be done. Not sure how many photography emergencies I will ever have to make me resort to this...

09-15-2015, 02:04 PM	#54
THoog Loyal Site Supporter Join Date: Aug 2012 Location: North Carolina Photos: Gallery \| Albums Posts: 3,685	Originally posted by UncleVanya photography emergencies I think this sort of emergency would be of the "severe attack of LBA" variety.

09-15-2015, 02:05 PM	#55
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Originally posted by THoog I think this sort of emergency would be of the "severe attack of LBA" variety. Yes... that seems about right. "If only I had a 105 f/2.5 Pentax... wait Nikon made those!" ---------- Post added 09-15-15 at 05:06 PM ---------- Originally posted by THoog I think this sort of emergency would be of the "severe attack of LBA" variety. Yes... that seems about right. "If only I had a 105 f/2.5 Pentax... wait Nikon made those!" But to bring this back to the subject - I did enjoy using a 7.5mm Nikon Fisheye that required the mirror be locked up to use. It was fun - you used a viewfinder with it since there was no way to see the image otherwise until you developed the film.

09-15-2015, 02:19 PM	#56
THoog Loyal Site Supporter Join Date: Aug 2012 Location: North Carolina Photos: Gallery \| Albums Posts: 3,685	Originally posted by UncleVanya Yes... that seems about right. "If only I had a 105 f/2.5 Pentax... wait Nikon made those!" Exactly. I've had brief LBA attacks like that, but have (mostly) been able to fight it off with medication and blows to the head. People just don't understand what a terrible, terrible disease it is. One of my favorite fishy toys is an old Kenko 180-degree adapter that does a full-circle FE on a 50mm (FF) or 35mm (APSC) lens. It's the one piece of gear that has ever caused a stranger to walk up to me and ask "what is that lens?"

09-15-2015, 02:47 PM	#57
Driline Pentaxian Join Date: Dec 2012 Location: IOWA Where the Tall Corn Grows Photos: Gallery Posts: 3,697	Originally posted by kiwi_jono Ok I will play too. Its a fun lens for sure. Wow. That lens also puts the steering wheel on the wrong side of the car too!