[ivanvernon]

The purpose of this club is to offer a forum for presenting images created with the use of leaf shutter (LS) lenses with an emphasis upon Pentax LS lenses. It will also provide a forum to compare and discuss LS lens features, associated equipment, and the best practices and techniques for using these lenses. Pentax to the best of my knowledge offers only four medium format leaf shutter (LS) lenses. These are the SMC Pentax 645 LS 75mm f2.8, the SMC Pentax 645 LS 135mm f 4.0, the Super-Multi-Coated Pentax 67 90mm f 2.8 L.S., and the SMC Pentax 67 LS 165mm f 4.0. If Pentax has produced any other LS lenses, I have been unable to locate references to them. Other lens makers such as Hasselblad and Mamiya have also produced LS lenses.

So . . . show us some images. Explain how you set up your rig, what problems you had and how you solved them. Tell us what works best for you, when LS lenses come in handy and when to leave them on the shelf.

To start the ball rolling, and with apologies to professional product photographers everywhere, I include a copy of the LS lenses in my collection. I am missing the 90mm LS, but may start shopping for it soon if this Club takes off and gathers enough members to become interesting!

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[Silent Street]

I have the 165 f4 LS lens for the Pentax 67, but have not used it since I think May this year. I had intent during COVID Lockdown Mk 1 (March to May) to set up a small studio with Bowens strobes to make use of the leaf shutter function and higher sync speed, but this never eventuated, as supply difficulties and restrictions on movement screwed everything (and everyone...).

The idiosyncracies of these lenses must be across new users at the risk of causing damage to the camera, specifically the 6x7 67 e.g. mirror lock-up can be used with the 90mm LS in LS mode, but it will cause an irreversible jam with the 165mm LS in LS mode. Also, the camera's shutter must always be set to the lowest available sync speed (1/4s or 1/8s for the 6x7 / 67) in order to specifically synchronise with the active leaf shutter. If this is not done (e.g. using a too-high Tv value), the frame will be blank or only very partially exposed and the leaf shutter, if activated, may freeze.

It would be very unusual however to use MLU in a traditional studio situation, but would not be unheard of in e.g. the landscape/scenic context where LS can also be put to effective use in making a double exposure, and not in LS-mode.

[ivanvernon]

A

I have the 165 f4 LS lens for the Pentax 67, but have not used it since I think May this year. I had intent during COVID Lockdown Mk 1 (March to May) to set up a small studio with Bowens strobes to make use of the leaf shutter function and higher sync speed, but this never eventuated, as supply difficulties and restrictions on movement screwed everything (and everyone...).

The idiosyncracies of these lenses must be across new users at the risk of causing damage to the camera, specifically the 6x7 67 e.g. mirror lock-up can be used with the 90mm LS in LS mode, but it will cause an irreversible jam with the 165mm LS in LS mode. Also, the camera's shutter must always be set to the lowest available sync speed (1/4s or 1/8s for the 6x7 / 67) in order to specifically synchronise with the active leaf shutter. If this is not done (e.g. using a too-high Tv value), the frame will be blank or only very partially exposed and the leaf shutter, if activated, may freeze.

It would be very unusual however to use MLU in a traditional studio situation, but would not be unheard of in e.g. the landscape/scenic context where LS can also be put to effective use in making a double exposure, and not in LS-mode.

Thanks for your comments--just exactly the sort of technical information and advice that I hope this Club thread will encourage. Great good luck to you in your photographic endeavors.

Added note: Here is another Forum worth reviewing: https://www.pentaxforums.com/forums/48-pentax-medium-format/280273-pentax-64...y-success.html

[texandrews]

I have both the 645 LS lenses, and have used them successfully---and not. They can be quirky, and there can be mis-fires for reasons I've never understood. But I will say this---both are sharp, and the 135 is very much so, one of my sharpest lenses.

So far I haven't found a lot of uses for their FL's, though.

[ivanvernon]

I have both the 645 LS lenses, and have used them successfully---and not. They can be quirky, and there can be mis-fires for reasons I've never understood. But I will say this---both are sharp, and the 135 is very much so, one of my sharpest lenses.

So far I haven't found a lot of uses for their FL's, though.

Good points. I agree with your comments on sharpness, though for the 75mm there are two other alternatives in the A and FA versions. I do use the 135 occasionally because of its sharpness, though my Leica-R 135mm has taken over this role on the K-1. I have 5 or 6 other 135mm lenses that seldom see any use, and which I would sell if they were worth anything. Thanks for supporting this new club thread, and please give us some photos when time permits.

[gofour3]

I have the 6x7 90/2.8 and 67 165/4 leaf shutters.

One tip is to make sure you don't leave the LS cocked when storing the lens, as this can leave too much tension on the LS springs and damage them over time.

Phil.

[texandrews]

Good points. I agree with your comments on sharpness, though for the 75mm there are two other alternatives in the A and FA versions. I do use the 135 occasionally because of its sharpness, though my Leica-R 135mm has taken over this role on the K-1. I have 5 or 6 other 135mm lenses that seldom see any use, and which I would sell if they were worth anything. Thanks for supporting this new club thread, and please give us some photos when time permits.

I'm in the middle of sorting a new computer I had to buy---a kick in the groin at this time of year, but necessary as the old unit has given its last. I'm taking the opportunity to get some discipline into my photo files. That translates into a bit of a wait, I'm afraid. Also---I haven't been satisfied with my images posted anywhere but Zenfolio, so I need to re-check some things about posting here.

[barondla]

Don't own and never have used any of these Pentax leaf shutter lenses. Will a flash work from the hotshoe or must it be plugged into the pc connector on the lens? If the hotshoe works it might be interesting to use one with the 645Z and Pentax AF160 ringflash for macro.

There is another Pentax leaf shutter option not mentioned so far. The Pentax Q, which has no mechanical focal plane shutter, has leaf shutter lenses. The Pentax PK to Q adapter allows using K mount lenses on the Q and has a leaf shutter inside.

Thanks,
barondla

[ivanvernon]

Don't own and never have used any of these Pentax leaf shutter lenses. Will a flash work from the hotshoe or must it be plugged into the pc connector on the lens? If the hotshoe works it might be interesting to use one with the 645Z and Pentax AF160 ringflash for macro.

There is another Pentax leaf shutter option not mentioned so far. The Pentax Q, which has no mechanical focal plane shutter, has leaf shutter lenses. The Pentax PK to Q adapter allows using K mount lenses on the Q and has a leaf shutter inside.

Thanks,
barondla

With Pentax LS lenses the setup is for the lens to be connected to the flash unit (installed on hotshoe) by means of a cord. Few flash units (none that I have identified) have a port to make this connection, so you have to find some means of creating a port for the connection. I do it by installing one of those voltage protectors/limiters in the hotshoe and then installing the flash unit in the limiter. The limiter has a port in front to insert the cord coming from the lens. With apologies to commercial product photographers everywhere, I am including a photo of my setup for the Pentax 645Z, the Pentax 645 75mm f 2.8 LS, and the Pentax AF 200T flash unit.

[barondla]

With Pentax LS lenses the setup is for the lens to be connected to the flash unit (installed on hotshoe) by means of a cord. Few flash units (none that I have identified) have a port to make this connection, so you have to find some means of creating a port for the connection. I do it by installing one of those voltage protectors/limiters in the hotshoe and then installing the flash unit in the limiter. The limiter has a port in front to insert the cord coming from the lens. With apologies to commercial product photographers everywhere, I am including a photo of my setup for the Pentax 645Z, the Pentax 645 75mm f 2.8 LS, and the Pentax AF 200T flash unit.

Thanks for the photo and explanation. I understand the connections now. The Pentax ring flash would work and has manual exposure mode to compensate for the loss of P-TTL.

So it's possible to use a Pentax 67 LS lens (with lens adapter) on the 645 or K mount camera?

Thanks for the help,
barondla

[ivanvernon]

Thanks for the photo and explanation. I understand the connections now. The Pentax ring flash would work and has manual exposure mode to compensate for the loss of P-TTL.

So it's possible to use a Pentax 67 LS lens (with lens adapter) on the 645 or K mount camera?

Thanks for the help,
barondla

The two 645 LS lens (75mm and 135mm) work very well on both the 645D and 645Z. When you mount the lens and set the shutter speed, the 645D/Z immediately light up with the letters "LS" and you are all set.

The 67/165mm LS is different. I set it up exactly the same way as shown in my photo. However, the 645 cameras do not automatically recognize it and display the "LS" designation. So I set the camera on manual mode, shutter at 1/8 second, ISO at minimum, and aperture at minimum (f 4.0). Turn on flash, set on manual mode and power at desired level depending on distance from model/object being photographed. Sometimes it works and you can get a photo, but other times it refuses to trigger the LS shutter to fire. Why? I don't know. You can try it with your equipment and maybe come up with a winning configuration. The simplest solution is to just buy the 645/135mm LS and adapt your work to use that focal length as it is a great, very sharp lens and available in th $200-$400 range depending upon condition, etc.

Good luck to you. I hope this helps.

Good luck.