Help: Not Sure What to do With Auto/Manual settings on 6X7 55mm 4 lens

**rollsman4** · 02-11-2017, 11:42 AM

Just received this lens in Excellent condition. It has a slide on the lens which says: Auto and manual. I tried to move the switch side to side to go from Auro to Manual and it just moves back to the Manual side . Also, How do I see the Exposure in the Viewfinder or Top LCD on my 645D?
I move the f stop but no Exposure number appears. Thank you. Dennis

**UncleVanya** · 02-11-2017, 11:59 AM

Which specific lens is it? Here's an A series lens (manual focus) for a 645 series camera. They don't have Auto/Manual switches that I am aware of. They have a button you press to move the aperture ring to the A position. Is that what you mean?

SMC Pentax-A 645 75mm F2.8 Reviews - 645 Normal Primes - Pentax Lens Reviews & Lens Database

**rollsman4** · 02-11-2017, 12:05 PM

Its a 55mm f4. 6x7 lens with a 645 Adaptor to use on my 645D. Thank you

**UncleVanya** · 02-11-2017, 12:28 PM

6x7 lenses use stop down metering on the 645D from what I read. I think that means leaving it on Manual.

Pablo Villegas · 02-11-2017, 02:33 PM

I don't have a Pentax 67, but on Mamiya's lenses, the Auto/Manual mode is for using auto stop down metering. That means that no matter what fstop you choose, the camera iris will always be wide open until just a moment before the shutter opens, that way you can and see and focus better before taking the picture. And it also tells the built in meter to meter with the Fstop you chose, instead of wide open. If you're using an dalater that doesn't have the Auto lettering, it doesn't supports it, so, the lens needs to be set to manual, and the Fstop you choose will in fact lower the amount of light getting in, from the moment you choose it, so your camera can only be used in Manual or Aperture priority mode.

Bob L · 02-11-2017, 03:21 PM

Originally posted by rollsman4

Just received this lens in Excellent condition. It has a slide on the lens which says: Auto and manual. I tried to move the switch side to side to go from Auro to Manual and it just moves back to the Manual side

When you slide the level across with your thumb, apply a little upward pull when it reaches the limit of travel and it should lock there......it confused me too.

Bob

Silent Street · 02-11-2017, 04:46 PM

Push the lever down until it clicks into place in the Manual position.
Tap the top part of the lever to release it (it will then spring back to auto). There is no difference to the operation of the Auto/Manual lever on this or any other Pentax 67 lens.
Stop-down metering is used on any camera other than the native 6x7 / 67 bodies, and this is the case with your 645D, thus exposure should be set manually (in manual mode).

**rollsman4** · 02-11-2017, 08:02 PM

Originally posted by Silent Street

Push the lever down until it clicks into place in the Manual position.
Tap the top part of the lever to release it (it will then spring back to auto). There is no difference to the operation of the Auto/Manual lever on this or any other Pentax 67 lens.
Stop-down metering is used on any camera other than the native 6x7 / 67 bodies, and this is the case with your 645D, thus exposure should be set manually (in manual mode).

Fantastic. Thank you all for helping me out with this. Just 1 thing more: Its normal NOT to see the aperture in the top LCD ? Correct?

Pablo Villegas · 02-11-2017, 11:20 PM

Originally posted by rollsman4

Fantastic. Thank you all for helping me out with this. Just 1 thing more: Its normal NOT to see the aperture in the top LCD ? Correct?

Yeah, there are no electronics telling the camera body which aperture you chose. But it can measure amount of light, and expose accordingly.

**rollsman4** · 02-13-2017, 06:08 AM

Thank you all. I tried to slide and lock and it worked... a liitle tricky. Great Build quality. I am going to stay with this one and not go after a 67 55mm due to the problems I read about. Thank you

02-11-2017, 11:42 AM	#1
rollsman4 Site Supporter Join Date: Nov 2014 Posts: 459	Help: Not Sure What to do With Auto/Manual settings on 6X7 55mm 4 lens Just received this lens in Excellent condition. It has a slide on the lens which says: Auto and manual. I tried to move the switch side to side to go from Auro to Manual and it just moves back to the Manual side . Also, How do I see the Exposure in the Viewfinder or Top LCD on my 645D? I move the f stop but no Exposure number appears. Thank you. Dennis

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02-11-2017, 11:59 AM	#2
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	Which specific lens is it? Here's an A series lens (manual focus) for a 645 series camera. They don't have Auto/Manual switches that I am aware of. They have a button you press to move the aperture ring to the A position. Is that what you mean? SMC Pentax-A 645 75mm F2.8 Reviews - 645 Normal Primes - Pentax Lens Reviews & Lens Database

02-11-2017, 12:05 PM	#3
rollsman4 Site Supporter Join Date: Nov 2014 Posts: 459 Original Poster	Its a 55mm f4. 6x7 lens with a 645 Adaptor to use on my 645D. Thank you

02-11-2017, 12:28 PM	#4
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,401	6x7 lenses use stop down metering on the 645D from what I read. I think that means leaving it on Manual.

02-11-2017, 02:33 PM	#5
Pablo Villegas Senior Member Join Date: Sep 2016 Posts: 158	I don't have a Pentax 67, but on Mamiya's lenses, the Auto/Manual mode is for using auto stop down metering. That means that no matter what fstop you choose, the camera iris will always be wide open until just a moment before the shutter opens, that way you can and see and focus better before taking the picture. And it also tells the built in meter to meter with the Fstop you chose, instead of wide open. If you're using an dalater that doesn't have the Auto lettering, it doesn't supports it, so, the lens needs to be set to manual, and the Fstop you choose will in fact lower the amount of light getting in, from the moment you choose it, so your camera can only be used in Manual or Aperture priority mode.

02-11-2017, 03:21 PM	#6
Bob L Senior Member Join Date: Mar 2016 Location: La Vienne (86), France Posts: 223	Originally posted by rollsman4 Just received this lens in Excellent condition. It has a slide on the lens which says: Auto and manual. I tried to move the switch side to side to go from Auro to Manual and it just moves back to the Manual side When you slide the level across with your thumb, apply a little upward pull when it reaches the limit of travel and it should lock there......it confused me too. Bob

02-11-2017, 04:46 PM	#7
Silent Street Veteran Member Join Date: Nov 2011 Location: Castlemaine, Victoria, AUS Photos: Albums Posts: 1,151	Push the lever down until it clicks into place in the Manual position. Tap the top part of the lever to release it (it will then spring back to auto). There is no difference to the operation of the Auto/Manual lever on this or any other Pentax 67 lens. Stop-down metering is used on any camera other than the native 6x7 / 67 bodies, and this is the case with your 645D, thus exposure should be set manually (in manual mode).

02-11-2017, 08:02 PM	#8
rollsman4 Site Supporter Join Date: Nov 2014 Posts: 459 Original Poster	Originally posted by Silent Street Push the lever down until it clicks into place in the Manual position. Tap the top part of the lever to release it (it will then spring back to auto). There is no difference to the operation of the Auto/Manual lever on this or any other Pentax 67 lens. Stop-down metering is used on any camera other than the native 6x7 / 67 bodies, and this is the case with your 645D, thus exposure should be set manually (in manual mode). Fantastic. Thank you all for helping me out with this. Just 1 thing more: Its normal NOT to see the aperture in the top LCD ? Correct?

02-11-2017, 11:20 PM	#9
Pablo Villegas Senior Member Join Date: Sep 2016 Posts: 158	Originally posted by rollsman4 Fantastic. Thank you all for helping me out with this. Just 1 thing more: Its normal NOT to see the aperture in the top LCD ? Correct? Yeah, there are no electronics telling the camera body which aperture you chose. But it can measure amount of light, and expose accordingly.

02-13-2017, 06:08 AM	#10
rollsman4 Site Supporter Join Date: Nov 2014 Posts: 459 Original Poster	Thank you all. I tried to slide and lock and it worked... a liitle tricky. Great Build quality. I am going to stay with this one and not go after a 67 55mm due to the problems I read about. Thank you