Are there any single element K-Mount lenses?

lytrytyr · 06-27-2013, 08:01 AM

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 Not a Number

How about pinhole lenses?

They don't even have a single element!

**grahame** · 06-27-2013, 09:08 AM

The mount cover lens on Q is the only one like that from pentax

Not a Number · 06-27-2013, 09:32 AM

Holga "pinhole" lenses have a plastic lens:

HOLGA HL-P Lens for PENTAX DSLR SLR K-5 K-r K-x K-m K-7 K20D K110D LOMO | eBay

lytrytyr · 06-27-2013, 09:48 AM

Originally posted by Not a Number

Holga "pinhole" lenses have a plastic lens:

HOLGA HL-P Lens for PENTAX DSLR SLR K-5 K-r K-x K-m K-7 K20D K110D LOMO | eBay

According to its "specifiation" (sic!),
that's an optical lens that needs focusing, not a pinhole.

Not a Number · 06-27-2013, 04:45 PM

My bad. However the Holga HL-P has only a single element.

lytrytyr · 06-27-2013, 06:23 PM

Originally posted by Not a Number

However the Holga HL-P has only a single element.

Right, it certainly answers OP's question.

ignmar · 06-28-2013, 06:39 AM

konstruktor DIY kit from lomography it lens got 1 element you can screw it into your K mount with M42 adapter

TropicalMonkey · 06-28-2013, 08:03 AM

Originally posted by ignmar

konstruktor DIY kit from lomography it lens got 1 element you can screw it into your K mount with M42 adapter

Well.. I am building my own single element lens! I had a cheap Kalimar, whose mount was not compatible with Pentax. I am using its front element and the helicoid mechanism to build my own manual focus lens with no aperture control (always wide open). Looks like the results are almost as expected but due to lack of a proper camera mount, it is a little hard to use. I am trying to figure out how to attach a K-mount!

Na Horuk · 06-28-2013, 08:20 AM

There are many meniscus, body cap and pin-hole type lenses out there, don't know if you would count them as "single element" and don't know if they actually are just a hole or if they have some kind of lens in there. And some might need adapters. But I don't have any list on hand and Adam is the authority on actual Pentax brand stuff

ignmar · 06-28-2013, 08:24 AM

Originally posted by TropicalMonkey

Well.. I am building my own single element lens! I had a cheap Kalimar, whose mount was not compatible with Pentax. I am using its front element and the helicoid mechanism to build my own manual focus lens with no aperture control (always wide open). Looks like the results are almost as expected but due to lack of a proper camera mount, it is a little hard to use. I am trying to figure out how to attach a K-mount!

if you need just a mount that quite easy just buy a cheap body cap and cut out the middle piece then glue it with hot glue there will be fit just fine.

TropicalMonkey · 06-28-2013, 08:43 AM

Originally posted by ignmar

if you need just a mount that quite easy just buy a cheap body cap and cut out the middle piece then glue it with hot glue there will be fit just fine.

Very good idea! I have several body-caps lying around.

wildman · 06-28-2013, 08:46 AM

Not entirely irrelevant to this thread...

..a Fraunhofer achromatic doublet (two elements in one group) brings red and blue light to the same focus.
500mm FL f/5 at about 80 feet and 30 feet as I recall. Generally the fewer the elements the better the contrast all else being equal but it sometimes can take a lot of PP to get a achromat file to look right.
This scope cost 100 bucks new.

TropicalMonkey · 06-28-2013, 09:20 AM

Wow! Nice shots!!!

Originally posted by wildman

Generally the fewer the elements the better the contrast all else being equal

Minimal (or lack of) internal reflections and minimum number of elements in the "signal" path.

Originally posted by wildman

but it sometimes can take a lot of PP to get a achromat file to look right

Can you explain that, please?

Edit: I can't stop looking at those images! Did you do any post-processing at all?

BTW, what lens/scope is that?

scratchpaddy · 06-28-2013, 09:45 AM

Originally posted by TropicalMonkey

Well.. I am building my own single element lens! I had a cheap Kalimar, whose mount was not compatible with Pentax. I am using its front element and the helicoid mechanism to build my own manual focus lens with no aperture control (always wide open). Looks like the results are almost as expected but due to lack of a proper camera mount, it is a little hard to use. I am trying to figure out how to attach a K-mount!

Inspired by this thread, I did something like that yesterday with the front element of a fungus-infected JCPenney zoom. I just used toilet paper tubes and tape.

You can see the results here:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/229186-tp-special.html

One sample:

TropicalMonkey · 06-28-2013, 09:59 AM

Is that the reason to have more than one lens -- to focus both ends of the spectrum to the same point? The lens material has to be different on those two lenses then.
I also took several shots but all indoor, so I didn't notice the chromatic abberation, it all looked "dreamy"!!

06-28-2013, 08:46 AM	#27
wildman Veteran Member Join Date: Jun 2008 Location: Flyover America Posts: 4,469	Not entirely irrelevant to this thread... ..a Fraunhofer achromatic doublet (two elements in one group) brings red and blue light to the same focus. 500mm FL f/5 at about 80 feet and 30 feet as I recall. Generally the fewer the elements the better the contrast all else being equal but it sometimes can take a lot of PP to get a achromat file to look right. This scope cost 100 bucks new. Last edited by wildman; 07-29-2013 at 04:23 AM.

06-28-2013, 09:20 AM	#28
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304 Original Poster	Wow! Nice shots!!! Originally posted by wildman Generally the fewer the elements the better the contrast all else being equal Minimal (or lack of) internal reflections and minimum number of elements in the "signal" path. Originally posted by wildman but it sometimes can take a lot of PP to get a achromat file to look right Can you explain that, please? Edit: I can't stop looking at those images! Did you do any post-processing at all? BTW, what lens/scope is that? Last edited by TropicalMonkey; 06-28-2013 at 09:25 AM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Are there any tiny, good, cheap 50-ish lens for the Q	GibbyTheMole	Pentax Q	3	01-23-2013 05:01 PM
Tessar Type 4-element lens in K-mount?	Hamster	Pentax SLR Lens Discussion	12	06-19-2012 03:55 PM
New to the forum and looking for a 49mm reversing k mount, any for sale out there?	kd1	Welcomes and Introductions	5	02-04-2012 06:04 PM
Are there any F2.8 Macro lenses that are STILL F2.8 at macro distances?	Unsinkable II	Pentax SLR Lens Discussion	58	10-03-2010 05:25 PM
Are there any cheap AF primes?	Steve Beswick	Pentax SLR Lens Discussion	14	10-23-2009 01:54 AM

06-27-2013, 08:01 AM	#16
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	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 Not a Number How about pinhole lenses? They don't even have a single element!

06-27-2013, 09:08 AM	#17
grahame Loyal Site Supporter Join Date: Aug 2011 Photos: Albums Posts: 2,041	The mount cover lens on Q is the only one like that from pentax

06-27-2013, 09:32 AM	#18
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Holga "pinhole" lenses have a plastic lens: HOLGA HL-P Lens for PENTAX DSLR SLR K-5 K-r K-x K-m K-7 K20D K110D LOMO \| eBay

06-27-2013, 09:48 AM	#19
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by Not a Number Holga "pinhole" lenses have a plastic lens: HOLGA HL-P Lens for PENTAX DSLR SLR K-5 K-r K-x K-m K-7 K20D K110D LOMO \| eBay According to its "specifiation" (sic!), that's an optical lens that needs focusing, not a pinhole.

06-27-2013, 04:45 PM	#20
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	My bad. However the Holga HL-P has only a single element.

06-27-2013, 06:23 PM	#21
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by Not a Number However the Holga HL-P has only a single element. Right, it certainly answers OP's question.

06-28-2013, 06:39 AM	#22
ignmar Junior Member Join Date: Jun 2013 Location: Batam Posts: 43	konstruktor DIY kit from lomography it lens got 1 element you can screw it into your K mount with M42 adapter

06-28-2013, 08:03 AM	#23
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304 Original Poster	Originally posted by ignmar konstruktor DIY kit from lomography it lens got 1 element you can screw it into your K mount with M42 adapter Well.. I am building my own single element lens! I had a cheap Kalimar, whose mount was not compatible with Pentax. I am using its front element and the helicoid mechanism to build my own manual focus lens with no aperture control (always wide open). Looks like the results are almost as expected but due to lack of a proper camera mount, it is a little hard to use. I am trying to figure out how to attach a K-mount!

06-28-2013, 08:20 AM	#24
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	There are many meniscus, body cap and pin-hole type lenses out there, don't know if you would count them as "single element" and don't know if they actually are just a hole or if they have some kind of lens in there. And some might need adapters. But I don't have any list on hand and Adam is the authority on actual Pentax brand stuff

06-28-2013, 08:24 AM	#25
ignmar Junior Member Join Date: Jun 2013 Location: Batam Posts: 43	Originally posted by TropicalMonkey Well.. I am building my own single element lens! I had a cheap Kalimar, whose mount was not compatible with Pentax. I am using its front element and the helicoid mechanism to build my own manual focus lens with no aperture control (always wide open). Looks like the results are almost as expected but due to lack of a proper camera mount, it is a little hard to use. I am trying to figure out how to attach a K-mount! if you need just a mount that quite easy just buy a cheap body cap and cut out the middle piece then glue it with hot glue there will be fit just fine.

06-28-2013, 08:43 AM	#26
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304 Original Poster	Originally posted by ignmar if you need just a mount that quite easy just buy a cheap body cap and cut out the middle piece then glue it with hot glue there will be fit just fine. Very good idea! I have several body-caps lying around.

06-28-2013, 09:45 AM	#29
scratchpaddy Pentaxian Join Date: Feb 2013 Location: Phoenix Posts: 3,361	Originally posted by TropicalMonkey Well.. I am building my own single element lens! I had a cheap Kalimar, whose mount was not compatible with Pentax. I am using its front element and the helicoid mechanism to build my own manual focus lens with no aperture control (always wide open). Looks like the results are almost as expected but due to lack of a proper camera mount, it is a little hard to use. I am trying to figure out how to attach a K-mount! Inspired by this thread, I did something like that yesterday with the front element of a fungus-infected JCPenney zoom. I just used toilet paper tubes and tape. You can see the results here: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/229186-tp-special.html One sample:

06-28-2013, 09:59 AM	#30
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304 Original Poster	Is that the reason to have more than one lens -- to focus both ends of the spectrum to the same point? The lens material has to be different on those two lenses then. I also took several shots but all indoor, so I didn't notice the chromatic abberation, it all looked "dreamy"!!