Manual lenses- AV and M modes K100d

wandat · 06-24-2007, 06:57 AM

I suppose I'm just dense but after shooting with my K100d for a couple of weeks (good results) I've discovered that in the AV mode my aperture adjustments of my non automatic lenses was a waste of time.

Problem #1 Now I'm interested in trying the manual mode, and in the viewfinder I can see the change of shutter speeds I'm selecting but - how do I know if I'm selecting the right one, is the aperture ring now in use by the camera (Custom setting in use and aperture permitted is selected) I still get -- shown as the f stop value and I don't see a change in the ev values either.

Problem #2 Using built in flash, same lenses, do I have to "guess" the correct f stop or is there no correction here.

Sorry for the "newby" questions but I have read the manual so many times I'm now confused

Thanks for any help you can provide....

**Lowell Goudge** · 06-24-2007, 07:47 AM

Not 100% sure on the K100D

On the *istD and K10D pressing the green button in manual mode stops the lens down and sets the shutter speed once the lens is stopped down.

Using the depth of field preview activates the metering in matched needle mode and you can dial up the shutter speed you want.

For flash mode, I think the K100D has only P-ttl, and as a result flash metering does not work at other than wide open apature.

For flash, if you have a flash that has all 4 modes, Manual, Auto, TTL and P-TTL set the mode to auto, and you can then set on the flash the F Stop of the lens. The Af540FGZ can do this, I'm not sure of the others.

pschlute · 06-24-2007, 08:29 AM

I have the DS and as the prvious poster pointed out, in manual mode you select the aperture on the lens then use the "green" button to set the shutter speed. He also pointed out you can also use the DOF preview lever method too (again in manual mode), which enables you to select either aperture or shutter speed until you get a correct reading.

However the aperture display on the camera will always read ..... because there are no electrical connections between the lens and camera. The camera has no idea what the aperture is.

Lastly, as you have discovered the camera will take pictures in Av mode....however this is not recomended as all your exposures will be at widest aperture irrespective of what you actually set on the lens.

wandat · 06-24-2007, 10:03 AM

Thanks for the info however, I don't have a green button but believe it's sub might be a button labeled Av, However I haven't noticed any changes when trying to use it.... If I use the DOF (not sure I have that feature) what or how can I ensure I select the correct shutter speed for the aperture selected... Apparently this is not like my old P5 that where I set the aperture and the camera selected the shutter speed...

Are you saying the camera has no way of of reacting to any presets I do on the lens?

If aperture is not available to control image reaching the flash and in AV mode shutter is operating at 120 (I think) then how do I ensure properly exposed shots?

I'm even more confused........

pschlute · 06-24-2007, 10:57 AM

You have a button labelled AE-L. Press that while in manual mode with f8 set on the lens. You should hear the camera stop down and you will find it has set a shutter speed.

I dont know what else you expect it to do?

TDN · 06-24-2007, 11:10 AM

Yes, in M mode, AE-L gives you an automatic exposure.

you can read about the lens types and how to get automatic exposue with them here

Tom

wandat · 06-24-2007, 12:59 PM

Thanks pschulte and TDN, that is the mystery I have been trying to solve, the magic of the ae-l button. Worked like a champ. The TDN page and links are saved for future reference.

I also see this same button work with the flash in the same manner? Do I have to keep guessing as to what aperture opening when I use the flash? I did note that in manual the shutter is fixed at 120 (I think) so is guesswork all I have to set aperture with?

wandat · 06-25-2007, 04:13 AM

Anymore advice out there on the flash issue???????

egordon99 · 06-25-2007, 05:48 AM

P-TTL flash needs to know the aperture of the lens to calculate the flash power/duration needed for proper exposure. As M-lenses do not transmit this info to the body, the built-in flash ALWAYS fires at full power (at least on the *ist DS it does) So yes, you will have to control the flash exposure by adjusting the f-stop.

Not sure if anyone else mentioned it, but old Pentax SLR bodies had a mechanical linkage between the lens' aperture lever and the body so the body was aware of what f-stop the ring was set to. Pentax removed this link on their D-SLRs.

answerdude · 06-25-2007, 02:02 PM

Originally posted by egordon99

Not sure if anyone else mentioned it, but old Pentax SLR bodies had a mechanical linkage between the lens' aperture lever and the body so the body was aware of what f-stop the ring was set to. Pentax removed this link on their D-SLRs.

Does anyone know why Pentax might have left out this M Apature mechanical linkage in the new DSLRs? It would have made the manual bayonet lenses so much easier to use.

Samb4 · 06-25-2007, 08:44 PM

Originally posted by TDN

Yes, in M mode, AE-L gives you an automatic exposure.

you can read about the lens types and how to get automatic exposure with them here

Tom

I found there is another way to use a manual lens. When in manual mode, use the e-dial to set your preferred shutter speed. Then, while looking through the viewfinder, move the main switch to the preview position.

The camera will close the lens to whatever aperture you have selected. While looking through the viewfinder, you should see the shutter speed, the F-- and then the EV compensation which will be a number between +/- 3.0. Adjust the aperture ring until the EV compensation is as close to 0.0 as you can get.

Now you can take the picture.

This is a bit more cumbersome than the AE-L, but it does allow you to set the shutter speed first, and is pretty close to the way the K1000 worked.

Sam

axl · 06-26-2007, 11:08 AM

I've been usig the DOF preview way of setting correct exposure time for my Hoya HMC 135, but after trying AE-L button after reading about it here, I think those days are gone.

Anyway both of them work, if you want to experiment, and fiddle around than you can use DOF way, if you don't have time just press the AE-L button...

wandat · 06-28-2007, 06:32 PM

Thanks guys for all the help. I thought I understood the manual (re: flash usage), I appreciate your confirmation. I have been fairly good at guessing but will try the e - dial method although it looks a little clumsy, prbably mor accurate than my guessing. There is always my photo editor to adjust any poorly guessed exposures however...

roscot · 06-29-2007, 02:15 AM

You could always buy an inexpensive external manual or Thyristor flash. These will have an exposure chart on them to help set your f stop, or if you get a thyristor unit, they will have their own built in sensor for auto use.

Just be careful of trigger voltage. Pentax says less than 25 volts. Personally I'd go with one less than 10 volts. This link lists many 3rd party flashes and their trigger voltage.
Photo Strobe Trigger Voltages

RoxnDox · 06-29-2007, 08:24 AM

Originally posted by pschlute

You have a button labelled AE-L. Press that while in manual mode with f8 set on the lens. You should hear the camera stop down and you will find it has set a shutter speed.

I dont know what else you expect it to do?

It would have been nice if the Fine Manual had a better explanation of this very simple method... I too have a K100d and have been using trial-and-error shots with the preview setting to find the right aperture/shutterspeed combination whenever I use my old 80-200 or 135 M lenses. I had no idea that the AE-L button gave me the setting. Thnak you for the tip - it may be simple and obvious to you, but not to everyone until it's pointed out...

Jim

06-24-2007, 08:29 AM	#3
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,192	Manual lenses I have the DS and as the prvious poster pointed out, in manual mode you select the aperture on the lens then use the "green" button to set the shutter speed. He also pointed out you can also use the DOF preview lever method too (again in manual mode), which enables you to select either aperture or shutter speed until you get a correct reading. However the aperture display on the camera will always read ..... because there are no electrical connections between the lens and camera. The camera has no idea what the aperture is. Lastly, as you have discovered the camera will take pictures in Av mode....however this is not recomended as all your exposures will be at widest aperture irrespective of what you actually set on the lens.

06-24-2007, 10:57 AM	#5
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,192	Manual Exposure metering You have a button labelled AE-L. Press that while in manual mode with f8 set on the lens. You should hear the camera stop down and you will find it has set a shutter speed. I dont know what else you expect it to do?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
manual modes for flash	fredok1	Pentax DSLR Discussion	1	05-17-2010 11:10 AM
Av settings on P or manual modes	Papou	Pentax SLR Lens Discussion	1	12-30-2008 05:50 PM
Manual Focus Lenses and K100D	throndor	Pentax SLR Lens Discussion	2	10-14-2008 02:27 PM
Picture Modes K100D	richard64	Pentax DSLR Discussion	6	09-05-2007 03:59 AM
*ist DL Manual Lenses and M/Av Modes problem	ossi	Pentax DSLR Discussion	7	02-15-2007 09:43 PM

06-24-2007, 06:57 AM	#1
wandat Inactive Account Join Date: Jun 2007 Location: Logan, Ohio Posts: 13	Manual lenses- AV and M modes K100d I suppose I'm just dense but after shooting with my K100d for a couple of weeks (good results) I've discovered that in the AV mode my aperture adjustments of my non automatic lenses was a waste of time. Problem #1 Now I'm interested in trying the manual mode, and in the viewfinder I can see the change of shutter speeds I'm selecting but - how do I know if I'm selecting the right one, is the aperture ring now in use by the camera (Custom setting in use and aperture permitted is selected) I still get -- shown as the f stop value and I don't see a change in the ev values either. Problem #2 Using built in flash, same lenses, do I have to "guess" the correct f stop or is there no correction here. Sorry for the "newby" questions but I have read the manual so many times I'm now confused Thanks for any help you can provide....

06-24-2007, 07:47 AM	#2
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,886	Not 100% sure on the K100D On the *istD and K10D pressing the green button in manual mode stops the lens down and sets the shutter speed once the lens is stopped down. Using the depth of field preview activates the metering in matched needle mode and you can dial up the shutter speed you want. For flash mode, I think the K100D has only P-ttl, and as a result flash metering does not work at other than wide open apature. For flash, if you have a flash that has all 4 modes, Manual, Auto, TTL and P-TTL set the mode to auto, and you can then set on the flash the F Stop of the lens. The Af540FGZ can do this, I'm not sure of the others.

06-24-2007, 10:03 AM	#4
wandat Inactive Account Join Date: Jun 2007 Location: Logan, Ohio Posts: 13 Original Poster	Thanks for the info however, I don't have a green button but believe it's sub might be a button labeled Av, However I haven't noticed any changes when trying to use it.... If I use the DOF (not sure I have that feature) what or how can I ensure I select the correct shutter speed for the aperture selected... Apparently this is not like my old P5 that where I set the aperture and the camera selected the shutter speed... Are you saying the camera has no way of of reacting to any presets I do on the lens? If aperture is not available to control image reaching the flash and in AV mode shutter is operating at 120 (I think) then how do I ensure properly exposed shots? I'm even more confused........

06-24-2007, 11:10 AM	#6
TDN Forum Member Join Date: Jun 2007 Location: Belgium Photos: Gallery Posts: 96	Yes, in M mode, AE-L gives you an automatic exposure. you can read about the lens types and how to get automatic exposue with them here Tom

06-24-2007, 12:59 PM	#7
wandat Inactive Account Join Date: Jun 2007 Location: Logan, Ohio Posts: 13 Original Poster	Thanks pschulte and TDN, that is the mystery I have been trying to solve, the magic of the ae-l button. Worked like a champ. The TDN page and links are saved for future reference. I also see this same button work with the flash in the same manner? Do I have to keep guessing as to what aperture opening when I use the flash? I did note that in manual the shutter is fixed at 120 (I think) so is guesswork all I have to set aperture with?

06-25-2007, 04:13 AM	#8
wandat Inactive Account Join Date: Jun 2007 Location: Logan, Ohio Posts: 13 Original Poster	Anymore advice out there on the flash issue???????

06-25-2007, 05:48 AM	#9
egordon99 Inactive Account Join Date: Dec 2006 Location: Outside of Philly Posts: 1,561	P-TTL flash needs to know the aperture of the lens to calculate the flash power/duration needed for proper exposure. As M-lenses do not transmit this info to the body, the built-in flash ALWAYS fires at full power (at least on the *ist DS it does) So yes, you will have to control the flash exposure by adjusting the f-stop. Not sure if anyone else mentioned it, but old Pentax SLR bodies had a mechanical linkage between the lens' aperture lever and the body so the body was aware of what f-stop the ring was set to. Pentax removed this link on their D-SLRs.

06-25-2007, 02:02 PM	#10
answerdude New Member Join Date: Jun 2007 Location: Indianapolis Posts: 13	Originally posted by egordon99 Not sure if anyone else mentioned it, but old Pentax SLR bodies had a mechanical linkage between the lens' aperture lever and the body so the body was aware of what f-stop the ring was set to. Pentax removed this link on their D-SLRs. Does anyone know why Pentax might have left out this M Apature mechanical linkage in the new DSLRs? It would have made the manual bayonet lenses so much easier to use.

06-25-2007, 08:44 PM	#11
Samb4 Inactive Account Join Date: Jun 2007 Location: Calgary Posts: 10	Originally posted by TDN Yes, in M mode, AE-L gives you an automatic exposure. you can read about the lens types and how to get automatic exposure with them here Tom I found there is another way to use a manual lens. When in manual mode, use the e-dial to set your preferred shutter speed. Then, while looking through the viewfinder, move the main switch to the preview position. The camera will close the lens to whatever aperture you have selected. While looking through the viewfinder, you should see the shutter speed, the F-- and then the EV compensation which will be a number between +/- 3.0. Adjust the aperture ring until the EV compensation is as close to 0.0 as you can get. Now you can take the picture. This is a bit more cumbersome than the AE-L, but it does allow you to set the shutter speed first, and is pretty close to the way the K1000 worked. Sam

06-26-2007, 11:08 AM	#12
axl Veteran Member Join Date: Mar 2007 Location: Nove Zamky, Slovakia Photos: Gallery \| Albums Posts: 7,183	I've been usig the DOF preview way of setting correct exposure time for my Hoya HMC 135, but after trying AE-L button after reading about it here, I think those days are gone. Anyway both of them work, if you want to experiment, and fiddle around than you can use DOF way, if you don't have time just press the AE-L button...

Thread Tools	Search this Thread
	Search this Thread: Advanced Search

06-28-2007, 06:32 PM	#13
wandat Inactive Account Join Date: Jun 2007 Location: Logan, Ohio Posts: 13 Original Poster	Thanks guys for all the help. I thought I understood the manual (re: flash usage), I appreciate your confirmation. I have been fairly good at guessing but will try the e - dial method although it looks a little clumsy, prbably mor accurate than my guessing. There is always my photo editor to adjust any poorly guessed exposures however...

06-29-2007, 02:15 AM	#14
roscot Veteran Member Join Date: Sep 2006 Location: Virginia Beach VA USA Photos: Gallery Posts: 1,363	You could always buy an inexpensive external manual or Thyristor flash. These will have an exposure chart on them to help set your f stop, or if you get a thyristor unit, they will have their own built in sensor for auto use. Just be careful of trigger voltage. Pentax says less than 25 volts. Personally I'd go with one less than 10 volts. This link lists many 3rd party flashes and their trigger voltage. Photo Strobe Trigger Voltages

06-29-2007, 08:24 AM	#15
RoxnDox Pentaxian Join Date: May 2007 Location: Gig Harbor, Washington, USA, Terra Photos: Gallery \| Albums Posts: 4,494	Originally posted by pschlute You have a button labelled AE-L. Press that while in manual mode with f8 set on the lens. You should hear the camera stop down and you will find it has set a shutter speed. I dont know what else you expect it to do? It would have been nice if the Fine Manual had a better explanation of this very simple method... I too have a K100d and have been using trial-and-error shots with the preview setting to find the right aperture/shutterspeed combination whenever I use my old 80-200 or 135 M lenses. I had no idea that the AE-L button gave me the setting. Thnak you for the tip - it may be simple and obvious to you, but not to everyone until it's pointed out... Jim