Tip on M-lens metering (is there a problem with that?)

GabrielFFontes · 10-18-2011, 06:48 AM

Hi guys.
I bought my first prime and first manual lens (ive been with my k-r for 18 days now), and its a 50mm M-F1.7
I really like the lens, but i hate to press the green button everytime i change the place where im aiming the camera, so i realized that if i didnt screwed the lens until completely the end, i would be able to use it on Av mode and change the aperture with the aperture ring. And it worked, now the camera is always metering and i can use only the aperture ring. Its much easier now! But is there a problem with that? Can it damage my lens/camera? (i guess not, right?)
Thanks, and i leave it as a tip

topace · 10-18-2011, 07:15 AM

The mount isn't that fickle (Though the fact that it's screwed into plastic really bugs me, and cost me my first DSLR), and the M 50mm/f1.7 is made from sturdier stuff than that. I can't guarantee that repeted improper use, with great forces at abnormal angles wouldn't damage it, but if you just unscrew it enough for the aperture lever to disengage, that shouldn't be a problem. Obviously, you have to be careful not to dismount and drop your lens.

The only real problem with shooting this way is that the image in the viewfinder is darker as it's stopped down. But I shoot M42 without camera aperture control, wich has the same problem, from time to time, and I think it's a fair price for the ability to use awesome lenses that cost almost nothing.

Also note that it's harder to find precise focus at narrow aperture settings, because the Depth of Field is deeper.

GabrielFFontes · 10-18-2011, 07:31 AM

Originally posted by topace

The mount isn't that fickle (Though the fact that it's screwed into plastic really bugs me, and cost me my first DSLR), and the 50mm/f1.7 is made from sturdier stuff than that. I can't guarantee that repeted improper use, with great forces at abnormal angles wouldn't damage it, but if you just unscrew it enough for the aperture lever to disengage, that shouldn't be a problem. Obviously, you have to be careful not to dismount and drop your lens.

The only real problem with shooting this way is that the image in the viewfinder is darker as it's stopped down. But I shoot M42 without camera aperture control, wich has the same problem, from time to time, and I think it's a fair price for the ability to use awesome lenses that cost almost nothing.

Also note that it's harder to find precise focus at narrow aperture settings, because the Depth of Field is deeper.

Yep, i just unscrew it a little bit...
And i've already noticed that focusing at narrow apertures is very dificult, and the camera wont show the focus confirmation dot, but that shouldnt be a problem, and i dont plan to shoot at any aperture smaller than f5.6, and almost always f1.7 at low light

Adam · 10-18-2011, 08:33 AM

If you like that approach, that's how all screwmount lenses work because they don't have the aperture control lever, so I'd consider getting a few of those!

Be careful so that your M lens doesn't fall off!

Adam
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altopiet · 10-18-2011, 08:35 AM

I removed the aperture lever from my old Vivitar 70-150mm, and also the ball bearing underneath the aperture ring, actually turning it more or less into an old preset lens like my Takumar 105, without the actual preset stop. You can always replace it again, but I find using it that way so easy, I am actually considering doing it to my Pentax 50/1.4

**Lowell Goudge** · 10-18-2011, 09:37 AM

you have discovered why M42 lenses are popular, but in reality, you don't really ned to press the green button each time you shoot.

All you need to do, is to press the green button when you change exposure or lighting situations. If you set the metering i.e. shutter and aperture as you lioke for the lighting, as long as nothing changes you are able to shoot again and again with the same settings.

It is only when you change the situation that you need to re-meter

for me, I shoot both M42 and K mount (as opposed to KA) and have likes and dislikes about both.

I like open aperture focusing and not manually stopping down for eac shot, and I also like the convenience of Av mode on M42's

Some people have drilled an extra locking pin hole, and others have removed the levers, but these should only be considered if you do't care about hurting the re-sale value of a lens.

10-18-2011, 06:48 AM	#1
GabrielFFontes Veteran Member Join Date: Jul 2011 Location: Rio de Janeiro, Brazil Posts: 647	Tip on M-lens metering (is there a problem with that?) Hi guys. I bought my first prime and first manual lens (ive been with my k-r for 18 days now), and its a 50mm M-F1.7 I really like the lens, but i hate to press the green button everytime i change the place where im aiming the camera, so i realized that if i didnt screwed the lens until completely the end, i would be able to use it on Av mode and change the aperture with the aperture ring. And it worked, now the camera is always metering and i can use only the aperture ring. Its much easier now! But is there a problem with that? Can it damage my lens/camera? (i guess not, right?) Thanks, and i leave it as a tip

10-18-2011, 07:15 AM	#2
topace Senior Member Join Date: Sep 2011 Location: Stockholm Posts: 198	The mount isn't that fickle (Though the fact that it's screwed into plastic really bugs me, and cost me my first DSLR), and the M 50mm/f1.7 is made from sturdier stuff than that. I can't guarantee that repeted improper use, with great forces at abnormal angles wouldn't damage it, but if you just unscrew it enough for the aperture lever to disengage, that shouldn't be a problem. Obviously, you have to be careful not to dismount and drop your lens. The only real problem with shooting this way is that the image in the viewfinder is darker as it's stopped down. But I shoot M42 without camera aperture control, wich has the same problem, from time to time, and I think it's a fair price for the ability to use awesome lenses that cost almost nothing. Also note that it's harder to find precise focus at narrow aperture settings, because the Depth of Field is deeper. Last edited by topace; 10-18-2011 at 08:13 AM. Reason: Specify lens

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10-18-2011, 07:31 AM	#3
GabrielFFontes Veteran Member Join Date: Jul 2011 Location: Rio de Janeiro, Brazil Posts: 647 Original Poster	Originally posted by topace The mount isn't that fickle (Though the fact that it's screwed into plastic really bugs me, and cost me my first DSLR), and the 50mm/f1.7 is made from sturdier stuff than that. I can't guarantee that repeted improper use, with great forces at abnormal angles wouldn't damage it, but if you just unscrew it enough for the aperture lever to disengage, that shouldn't be a problem. Obviously, you have to be careful not to dismount and drop your lens. The only real problem with shooting this way is that the image in the viewfinder is darker as it's stopped down. But I shoot M42 without camera aperture control, wich has the same problem, from time to time, and I think it's a fair price for the ability to use awesome lenses that cost almost nothing. Also note that it's harder to find precise focus at narrow aperture settings, because the Depth of Field is deeper. Yep, i just unscrew it a little bit... And i've already noticed that focusing at narrow apertures is very dificult, and the camera wont show the focus confirmation dot, but that shouldnt be a problem, and i dont plan to shoot at any aperture smaller than f5.6, and almost always f1.7 at low light

10-18-2011, 08:33 AM	#4
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	If you like that approach, that's how all screwmount lenses work because they don't have the aperture control lever, so I'd consider getting a few of those! Be careful so that your M lens doesn't fall off! Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

10-18-2011, 08:35 AM	#5
altopiet Veteran Member Join Date: Sep 2010 Location: The Gem of the Karoo, South Africa Photos: Gallery \| Albums Posts: 2,307	I removed the aperture lever from my old Vivitar 70-150mm, and also the ball bearing underneath the aperture ring, actually turning it more or less into an old preset lens like my Takumar 105, without the actual preset stop. You can always replace it again, but I find using it that way so easy, I am actually considering doing it to my Pentax 50/1.4

10-18-2011, 09:37 AM	#6
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	you have discovered why M42 lenses are popular, but in reality, you don't really ned to press the green button each time you shoot. All you need to do, is to press the green button when you change exposure or lighting situations. If you set the metering i.e. shutter and aperture as you lioke for the lighting, as long as nothing changes you are able to shoot again and again with the same settings. It is only when you change the situation that you need to re-meter for me, I shoot both M42 and K mount (as opposed to KA) and have likes and dislikes about both. I like open aperture focusing and not manually stopping down for eac shot, and I also like the convenience of Av mode on M42's Some people have drilled an extra locking pin hole, and others have removed the levers, but these should only be considered if you do't care about hurting the re-sale value of a lens.