Using Manual Lenses (M42 Screwmount, M , K) on Pentax DSLRs F--

StrasburgBarry · 05-22-2014, 03:49 AM

I have two completely manual lenses which I use on my Pentax K-5II, a 50mm older style Pentax with the stop down pin and a newer 500mm Opteka, f8. Note: These are both bayonet mount and don't require any M42 screw mount adapter. I rarely use the 50mm but do shoot more with the 500mm. My philosophy has been to use my Pentax 18-250mm completely auto-coupled lens in preference to the 50mm, unless for some reason I ABSOLUTELY need the f2 speed of the 50mm, which is very rare. The 500mm must always be used on pre-set, MANUAL ISO; since it WILL NOT WORK at all on auto-ISO. Once I set my f-stop on the 500mm lens, it will work with the camera's auto shutter speed. If you're hand holding the 500mm, you have to set the ISO to at least 800 on a bright day and 1600 on a cloudy day. On a tripod the 500mm will work OK as low as ISO 80. All this is crap you have to remember. So, my recommendation over a long time of experience of working with screw mount adapted to bayonet mount or non-auto bayonet mount lenses, is to avoid their use unless you absolutely have to. I view it more as a novelty that these old screw mount lenses fit today's camera bodies and part of the Pentax nostalgic ad campaign. In actual, practical use however, using screw mount or non-coupled bayonet mount lenses is a pain in the butt.

Last edited by StrasburgBarry; 05-22-2014 at 03:58 AM.

altopiet · 05-22-2014, 04:45 AM

Originally posted by StrasburgBarry

All this is crap you have to remember. So, my recommendation over a long time of experience of working with screw mount adapted to bayonet mount or non-auto bayonet mount lenses, is to avoid their use unless you absolutely have to. I view it more as a novelty that these old screw mount lenses fit today's camera bodies and part of the Pentax nostalgic ad campaign. In actual, practical use however, using screw mount or non-coupled bayonet mount lenses is a pain in the butt.

The least it does is give access to new entrants into the DSLR market, to some brilliant old glass, at a fair price. The adaptation to use the old lenses on a modern DSLR, is minimal, most folks actually complain about Manual focusing, due to the modern focus screens that’s optimized for auto focus....

Parallax · 05-22-2014, 05:05 AM - **1 Like**

This is similar to the "why would anyone go camping? That's what hotels are for." argument.
Yes, there is a lot to remember. Just leave your camera in Green Mode and use AF lenses and you'll be fine.

Tom S. · 05-22-2014, 05:44 AM

How jaded our society has become. Pain in the butt? Perhaps to some. Like having to change a TV channel without a remote control or drive a car with a manual transmission, or use a rotary dial telephone.

Nevertheless, as Christo pointed out, the ability to use some excellent legacy glass at a bargain cost far outweighs any perceived inconvenience. It would be nice if Pentax released a completely auto compatible 500mm lens, but a quick look at Nikon shows their version is over $8000. Few would buy it when they can get the manual version for $7500 less, so don't hold your breath waiting for Pentax to release one.

In the mean time, consider yourself lucky to have the availability of this focal length for such a low price, or if using it is causing you such pain, consider selling your gear and moving to another brand that will leave happy, albeit much poorer.

vonBaloney · 05-22-2014, 05:45 AM

Originally posted by StrasburgBarry

I have two completely manual lenses which I use on my Pentax K-5II, a 50mm older style Pentax with the stop down pin and a newer 500mm Opteka, f8. Note: These are both bayonet mount and don't require any M42 screw mount adapter. I rarely use the 50mm but do shoot more with the 500mm. My philosophy has been to use my Pentax 18-250mm completely auto-coupled lens in preference to the 50mm, unless for some reason I ABSOLUTELY need the f2 speed of the 50mm, which is very rare. The 500mm must always be used on pre-set, MANUAL ISO; since it WILL NOT WORK at all on auto-ISO. Once I set my f-stop on the 500mm lens, it will work with the camera's auto shutter speed. If you're hand holding the 500mm, you have to set the ISO to at least 800 on a bright day and 1600 on a cloudy day. On a tripod the 500mm will work OK as low as ISO 80. All this is crap you have to remember. So, my recommendation over a long time of experience of working with screw mount adapted to bayonet mount or non-auto bayonet mount lenses, is to avoid their use unless you absolutely have to. I view it more as a novelty that these old screw mount lenses fit today's camera bodies and part of the Pentax nostalgic ad campaign. In actual, practical use however, using screw mount or non-coupled bayonet mount lenses is a pain in the butt.

I use them all the time and it isn't a big deal, but it depends what you are shooting. AF is rarely important to me, but lenses with A contacts are much more convenient and the metering is better. Manual bayonets are probably my least favorite because of what you say -- fixed ISO, must use green button, but you get used to it quickly. Screw mounts I use in Av mode and can use auto-ISO as well if I like, a little nicer...

photolady95 · 05-22-2014, 06:48 AM

Originally posted by vonBaloney

fixed ISO, must use green button,

Not necessarily. I use M lenses without having to use the green button.

vonBaloney · 05-22-2014, 07:30 AM

Originally posted by photolady95

Not necessarily. I use M lenses without having to use the green button.

Elaborate?

Of course you don't HAVE to, but if you want to take a meter reading (and have it set the shutter speed for you). Only other option I know of is to use optical preview, which will show you the meter but not set the shutter. Or only shoot wide-open in Av mode...

photolady95 · 05-22-2014, 07:38 AM

When using my Pentax M50mm f2, I adjust aperture value, camera in M mode, MF, and I know that it is said that this still leaves the lens wide open but I get the shot exposed correctly, with f at 8 or above. I'm basically, shooting Macro shots when I do this.

vonBaloney · 05-22-2014, 07:48 AM

Originally posted by photolady95

When using my Pentax M50mm f2, I adjust aperture value, camera in M mode, MF, and I know that it is said that this still leaves the lens wide open but I get the shot exposed correctly, with f at 8 or above. I'm basically, shooting Macro shots when I do this.

Well ok, you adjust, based on what? At what point are you taking a meter reading? In other words, if my camera is set on something that is obviously not going to work -- let's say it is fairly dim and ISO is set at 80 and shutter speed at 1/4000, -- even with a wide-open aperture that's going to give me a black image. So you need to adjust ISO and shutter-speed both. Other than the sunny 16 rule, how to go about that? In M mode it will not change those settings ever unless you change them. So I would set the ISO to some reasonable value and hit the green button, which would set the shutter speed for me (which stops down the lens in the process so it is correct for any aperture I've set manually on the lens).

Now, if your camera is actually NOT in M mode, but in Av (or anything else but M), then it will automatically set the shutter (and the ISO if auto-ISO is on), but will only shoot wide-open. (Note that with K-mount M lenses, it will NEVER stop down the lens to your selected aperture if you are Av mode [or anything but M].) Sort of sounds like that is actually what you are doing? Are you sure you are really shooting at f/8 or you have just set the lens there and it is not actually stopping down?

photolady95 · 05-22-2014, 07:57 AM

I never shoot in anything other than M mode. I have a Auto everything camera but I like to be creative, and not use it like a glorified Point and Hope.

vonBaloney · 05-22-2014, 09:24 AM

Originally posted by photolady95

I never shoot in anything other than M mode. I have a Auto everything camera but I like to be creative, and not use it like a glorified Point and Hope.

But still -- do use the light meter in the camera? In M mode, in order to use it (with a M lens), that means green button. How do you determine your correct shutter speed/aperture/ISO for good exposure? Just eyeballing it?

photolady95 · 05-22-2014, 11:09 AM

Just because they say you have to use the green button doesn't mean it's set in stone. I know exposure is correct because my photos come out just as they are supposed to do so. Metering, most times I don't even pay attention. To you it may not make sense to ignore the meter, but that said, the meter isn't always correct either. To put it mildly, I am not your normal photographer, and I usually do things my own way.

I never came in here to argue a point I made, but since you pushed me into it, above is my answer and all I'm going to contribute to this discussion.

vonBaloney · 05-22-2014, 11:40 AM

Originally posted by photolady95

Just because they say you have to use the green button doesn't mean it's set in stone. I know exposure is correct because my photos come out just as they are supposed to do so. Metering, most times I don't even pay attention. To you it may not make sense to ignore the meter, but that said, the meter isn't always correct either. To put it mildly, I am not your normal photographer, and I usually do things my own way.

I never came in here to argue a point I made, but since you pushed me into it, above is my answer and all I'm going to contribute to this discussion.

I'm not trying to argue, just trying to find out how you determine what exposure settings to use if you are not using the green button. "I don't use the green button" doesn't tell me what you DO do...that's what I was trying to find out...as far as I know the only other option if you want to meter is to use the optical preview function (which would allow you to set the shutter speed first and then adjust aperture to proper exposure).

This thread is after all a technical/instructional one about the use of manual lenses on Pentax cameras and how one goes about doing things like metering, and getting the lens to stop down to the selected aperture. If you are simply saying, "I don't use the meter at all, so I don't care how to get it to work", well...

Parallax · 05-22-2014, 11:46 AM

Originally posted by vonBaloney

How do you determine your correct shutter speed/aperture/ISO for good exposure? Just eyeballing it?

Photography predates light meters by a good many decades. I doubt Mathew Brady had a Sekonic with him a Gettysburg.

photolady95 · 05-22-2014, 11:49 AM

I can't put it in words how it works, I just know it does. I set aperture to f8 to start, shutter speed is at 1/180 because I'm using onboard flash for my macro shots. ISO usually depends on what type of weather we're having, any where from ISO200 to ISO800. I don't like the green button because it doesn't always give me the shutter speed I need to get the job done when I am hand holding my camera, which is all the time for Macro work.

If you don't experiment, how are you ever going to learn what your camera can and can't do. If you don't experiment, you might was well buy a point and hope.

05-22-2014, 04:45 AM	#227
altopiet Veteran Member Join Date: Sep 2010 Location: The Gem of the Karoo, South Africa Photos: Gallery \| Albums Posts: 2,307	Originally posted by StrasburgBarry All this is crap you have to remember. So, my recommendation over a long time of experience of working with screw mount adapted to bayonet mount or non-auto bayonet mount lenses, is to avoid their use unless you absolutely have to. I view it more as a novelty that these old screw mount lenses fit today's camera bodies and part of the Pentax nostalgic ad campaign. In actual, practical use however, using screw mount or non-coupled bayonet mount lenses is a pain in the butt. The least it does is give access to new entrants into the DSLR market, to some brilliant old glass, at a fair price. The adaptation to use the old lenses on a modern DSLR, is minimal, most folks actually complain about Manual focusing, due to the modern focus screens that’s optimized for auto focus.... Last edited by altopiet; 05-22-2014 at 05:24 AM.

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05-22-2014, 03:49 AM	#226
StrasburgBarry Junior Member Join Date: Mar 2013 Location: Strasburg, Ohio, USA Posts: 48	I have two completely manual lenses which I use on my Pentax K-5II, a 50mm older style Pentax with the stop down pin and a newer 500mm Opteka, f8. Note: These are both bayonet mount and don't require any M42 screw mount adapter. I rarely use the 50mm but do shoot more with the 500mm. My philosophy has been to use my Pentax 18-250mm completely auto-coupled lens in preference to the 50mm, unless for some reason I ABSOLUTELY need the f2 speed of the 50mm, which is very rare. The 500mm must always be used on pre-set, MANUAL ISO; since it WILL NOT WORK at all on auto-ISO. Once I set my f-stop on the 500mm lens, it will work with the camera's auto shutter speed. If you're hand holding the 500mm, you have to set the ISO to at least 800 on a bright day and 1600 on a cloudy day. On a tripod the 500mm will work OK as low as ISO 80. All this is crap you have to remember. So, my recommendation over a long time of experience of working with screw mount adapted to bayonet mount or non-auto bayonet mount lenses, is to avoid their use unless you absolutely have to. I view it more as a novelty that these old screw mount lenses fit today's camera bodies and part of the Pentax nostalgic ad campaign. In actual, practical use however, using screw mount or non-coupled bayonet mount lenses is a pain in the butt. Last edited by StrasburgBarry; 05-22-2014 at 03:58 AM.

05-22-2014, 05:05 AM - 1 Like	#228
Parallax Senior Moderator Loyal Site Supporter Join Date: Apr 2008 Location: South Dakota Photos: Gallery Posts: 19,333	This is similar to the "why would anyone go camping? That's what hotels are for." argument. Yes, there is a lot to remember. Just leave your camera in Green Mode and use AF lenses and you'll be fine.

05-22-2014, 05:44 AM	#229
Tom S. Veteran Member Join Date: May 2008 Location: S.E. Michigan Photos: Albums Posts: 4,317	How jaded our society has become. Pain in the butt? Perhaps to some. Like having to change a TV channel without a remote control or drive a car with a manual transmission, or use a rotary dial telephone. Nevertheless, as Christo pointed out, the ability to use some excellent legacy glass at a bargain cost far outweighs any perceived inconvenience. It would be nice if Pentax released a completely auto compatible 500mm lens, but a quick look at Nikon shows their version is over $8000. Few would buy it when they can get the manual version for $7500 less, so don't hold your breath waiting for Pentax to release one. In the mean time, consider yourself lucky to have the availability of this focal length for such a low price, or if using it is causing you such pain, consider selling your gear and moving to another brand that will leave happy, albeit much poorer.

05-22-2014, 05:45 AM	#230
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by StrasburgBarry I have two completely manual lenses which I use on my Pentax K-5II, a 50mm older style Pentax with the stop down pin and a newer 500mm Opteka, f8. Note: These are both bayonet mount and don't require any M42 screw mount adapter. I rarely use the 50mm but do shoot more with the 500mm. My philosophy has been to use my Pentax 18-250mm completely auto-coupled lens in preference to the 50mm, unless for some reason I ABSOLUTELY need the f2 speed of the 50mm, which is very rare. The 500mm must always be used on pre-set, MANUAL ISO; since it WILL NOT WORK at all on auto-ISO. Once I set my f-stop on the 500mm lens, it will work with the camera's auto shutter speed. If you're hand holding the 500mm, you have to set the ISO to at least 800 on a bright day and 1600 on a cloudy day. On a tripod the 500mm will work OK as low as ISO 80. All this is crap you have to remember. So, my recommendation over a long time of experience of working with screw mount adapted to bayonet mount or non-auto bayonet mount lenses, is to avoid their use unless you absolutely have to. I view it more as a novelty that these old screw mount lenses fit today's camera bodies and part of the Pentax nostalgic ad campaign. In actual, practical use however, using screw mount or non-coupled bayonet mount lenses is a pain in the butt. I use them all the time and it isn't a big deal, but it depends what you are shooting. AF is rarely important to me, but lenses with A contacts are much more convenient and the metering is better. Manual bayonets are probably my least favorite because of what you say -- fixed ISO, must use green button, but you get used to it quickly. Screw mounts I use in Av mode and can use auto-ISO as well if I like, a little nicer...

05-22-2014, 06:48 AM	#231
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	Originally posted by vonBaloney fixed ISO, must use green button, Not necessarily. I use M lenses without having to use the green button.

05-22-2014, 07:30 AM	#232
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by photolady95 Not necessarily. I use M lenses without having to use the green button. Elaborate? Of course you don't HAVE to, but if you want to take a meter reading (and have it set the shutter speed for you). Only other option I know of is to use optical preview, which will show you the meter but not set the shutter. Or only shoot wide-open in Av mode...

05-22-2014, 07:38 AM	#233
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	When using my Pentax M50mm f2, I adjust aperture value, camera in M mode, MF, and I know that it is said that this still leaves the lens wide open but I get the shot exposed correctly, with f at 8 or above. I'm basically, shooting Macro shots when I do this.

05-22-2014, 07:48 AM	#234
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by photolady95 When using my Pentax M50mm f2, I adjust aperture value, camera in M mode, MF, and I know that it is said that this still leaves the lens wide open but I get the shot exposed correctly, with f at 8 or above. I'm basically, shooting Macro shots when I do this. Well ok, you adjust, based on what? At what point are you taking a meter reading? In other words, if my camera is set on something that is obviously not going to work -- let's say it is fairly dim and ISO is set at 80 and shutter speed at 1/4000, -- even with a wide-open aperture that's going to give me a black image. So you need to adjust ISO and shutter-speed both. Other than the sunny 16 rule, how to go about that? In M mode it will not change those settings ever unless you change them. So I would set the ISO to some reasonable value and hit the green button, which would set the shutter speed for me (which stops down the lens in the process so it is correct for any aperture I've set manually on the lens). Now, if your camera is actually NOT in M mode, but in Av (or anything else but M), then it will automatically set the shutter (and the ISO if auto-ISO is on), but will only shoot wide-open. (Note that with K-mount M lenses, it will NEVER stop down the lens to your selected aperture if you are Av mode [or anything but M].) Sort of sounds like that is actually what you are doing? Are you sure you are really shooting at f/8 or you have just set the lens there and it is not actually stopping down?

05-22-2014, 07:57 AM	#235
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	I never shoot in anything other than M mode. I have a Auto everything camera but I like to be creative, and not use it like a glorified Point and Hope.

05-22-2014, 09:24 AM	#236
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by photolady95 I never shoot in anything other than M mode. I have a Auto everything camera but I like to be creative, and not use it like a glorified Point and Hope. But still -- do use the light meter in the camera? In M mode, in order to use it (with a M lens), that means green button. How do you determine your correct shutter speed/aperture/ISO for good exposure? Just eyeballing it?

05-22-2014, 11:09 AM	#237
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	Just because they say you have to use the green button doesn't mean it's set in stone. I know exposure is correct because my photos come out just as they are supposed to do so. Metering, most times I don't even pay attention. To you it may not make sense to ignore the meter, but that said, the meter isn't always correct either. To put it mildly, I am not your normal photographer, and I usually do things my own way. I never came in here to argue a point I made, but since you pushed me into it, above is my answer and all I'm going to contribute to this discussion.

05-22-2014, 11:40 AM	#238
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by photolady95 Just because they say you have to use the green button doesn't mean it's set in stone. I know exposure is correct because my photos come out just as they are supposed to do so. Metering, most times I don't even pay attention. To you it may not make sense to ignore the meter, but that said, the meter isn't always correct either. To put it mildly, I am not your normal photographer, and I usually do things my own way. I never came in here to argue a point I made, but since you pushed me into it, above is my answer and all I'm going to contribute to this discussion. I'm not trying to argue, just trying to find out how you determine what exposure settings to use if you are not using the green button. "I don't use the green button" doesn't tell me what you DO do...that's what I was trying to find out...as far as I know the only other option if you want to meter is to use the optical preview function (which would allow you to set the shutter speed first and then adjust aperture to proper exposure). This thread is after all a technical/instructional one about the use of manual lenses on Pentax cameras and how one goes about doing things like metering, and getting the lens to stop down to the selected aperture. If you are simply saying, "I don't use the meter at all, so I don't care how to get it to work", well...

05-22-2014, 11:46 AM	#239
Parallax Senior Moderator Loyal Site Supporter Join Date: Apr 2008 Location: South Dakota Photos: Gallery Posts: 19,333	Originally posted by vonBaloney How do you determine your correct shutter speed/aperture/ISO for good exposure? Just eyeballing it? Photography predates light meters by a good many decades. I doubt Mathew Brady had a Sekonic with him a Gettysburg.

05-22-2014, 11:49 AM	#240
photolady95 Otis Memorial Pentaxian Join Date: May 2009 Location: Cruising the forum watching his back Photos: Gallery \| Albums Posts: 12,712	I can't put it in words how it works, I just know it does. I set aperture to f8 to start, shutter speed is at 1/180 because I'm using onboard flash for my macro shots. ISO usually depends on what type of weather we're having, any where from ISO200 to ISO800. I don't like the green button because it doesn't always give me the shutter speed I need to get the job done when I am hand holding my camera, which is all the time for Macro work. If you don't experiment, how are you ever going to learn what your camera can and can't do. If you don't experiment, you might was well buy a point and hope.