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06-17-2010, 05:14 AM   #1
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How to use Av mode with manual lenses

Hi everyone,

I don't know if anyone has figured this out yet, but I thought I may as well post it. I was just inspecting my old Tokina 135mm f/2.8 lens, and was trying to figure out a way to use the old manual lenses in aperture-priority mode. Well, I figured it out.

This is only useful when you have a manual lens with an aperture ring, and no contacts on the lens that allow you to change the aperture in-camera.

It's very simple. All you have to do is remove the little black sliding part on the back of the lens.


Once you've removed that, go into Av mode, and start turning the aperture ring and you'll see the exposure start to change.

I used a little high speed dremel, but I'm sure you can find other tools to take it off. I'd recommend using some masking tape over the rear mount, just so your glass keeps clean.

-Isaac


Last edited by IsaacSteiner; 06-17-2010 at 06:31 AM.
06-17-2010, 06:11 AM - 1 Like   #2
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QuoteOriginally posted by IsaacSteiner Quote
Hi everyone,

I don't know if anyone has figured this out yet, but I thought I may as well post it. I was just inspecting my old Tokina 135mm f/2.8 lens, and was trying to figure out a way to use the old manual lenses in aperture-priority mode. Well, I figured it out.

This is only useful when you have a manual lens with an aperture ring, and no contacts on the lens that allow you to change the aperture in-camera.

It's very simple. All you have to do is remove the little black sliding part on the back of the lens.


Once you've removed that, go into Av mode, and start turning the aperture ring and you'll see the exposure start to change.

I used a little high speed dremel, but I'm sure you can find other tools to take it off. I'd recommend using some masking tape over the rear mount, just so your glass keeps clean.

If you have any questions, just ask..

-Isaac
Well, nothing new with this. Last time I saw a post on this it was a dremmel also. But why do you have to be so violent? Take a screw driver, remove the mount, lift out the "little black sliding part" and the spring that will be attached to it. Put them both in an envelop, mark it with the lens name. Put the mount back and the screws. Et voilá, reversible. I've done that to some lenses temporary, most often my Tokina 400/5.6. Stepping it down one step improve the contrast and sharpness, while still bright enough to focus manually, and in this way I can shoot in Av mode. But I would never destroy a lens in this way when it is so easy to do it in a reversible way.
06-17-2010, 06:16 AM   #3
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He is right of course. I have a Vivitar 80-200 to prove it. It meters reasonably accurately with this modification. Anyone care to try it?
06-17-2010, 06:22 AM   #4
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Well .. first off, I didn't destroy the lens. It's perfect still, and the dremel does a perfect job.

Second, I didn't see it anywhere on the forums, so I thought I'd post it.

06-17-2010, 07:16 AM   #5
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Is Av really that important? Why not just use M and the green button?
06-17-2010, 07:30 AM   #6
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QuoteOriginally posted by brkl Quote
Is Av really that important? Why not just use M and the green button?
I think mostly the experience is one of wanting to experiement although in the debate of using Av versus the green button, Av completely removes pushing a green button from your steps.
In Av the camera meters and sets the shutter speed as soon as your finger is gently laid on the shutter release. With the stop down method of the green button, you push the green button and then push the shutter button.
Av = push shutter button halfway then take your shot.
Green button = push green button then take your shot. See? More letters in the procedure as well.

Also in Av you have use of other in camera options including but not limited to at least the convenience of EV compensation.
06-17-2010, 07:49 AM   #7
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QuoteOriginally posted by IsaacSteiner Quote
Well .. first off, I didn't destroy the lens. It's perfect still, and the dremel does a perfect job.

Second, I didn't see it anywhere on the forums, so I thought I'd post it.
You didn't destroy the lens per say but you did destroy whatever value it had. I bought an M50 1.4 and A28 2.8 a while back for $100 total because they had their clips taken off and I might even have overpaid by a tad bit. They were worth at least 2x as much had they not been ruined.

You didn't see it on the forum? That's funny, the last Canon user did the same exact thing to his K 28 f2.0 only last week. It's now worth 60% of its original value if he's lucky.

I think everybody pretty much knows about this by now, hence why we don't make threads about it. It's just ridiculous that people would pick the dremel over Douglas of Sweden's method, which is so much easier and SMARTER.

Oh and Av mode is great and all but it's not for all situations. Try shooting at f5.6 indoors with a flash gun. Or outdoors with f16+ and a split screen. You're going to wish you had the auto aperture set up then.
06-17-2010, 08:25 AM - 1 Like   #8
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QuoteOriginally posted by IsaacSteiner Quote
Well .. first off, I didn't destroy the lens. It's perfect still, and the dremel does a perfect job.

Second, I didn't see it anywhere on the forums, so I thought I'd post it.
In my oppinion you did destroy the lens. Try use it again on an un-crippled SLR body...or just on a DSLR with the green button...oops, it don't work any longer! And it would have been so easy to get the same benefits reversible.

It is actually not Apperture priority in the modern meaning. You are supposed to be able to change the apperture, but still meeter and focus wide open. In this way, you can get the DSLR to meeter continuously without having to press the green button (that can be neat), but if you want to focus at full open you still have to move the apperture ring back and forth between full open and the apperture you want to shoot at, which is at least as time consuming as the green button. So to have a benefit, you need to still work at an apperture where you can focus well enough. Actually, this method of meetering was called stopp-down-meetering somewhere back when the SLR market was a teenager. Not really the same as apperture priority, whatever the camera display says.

Non the less, this is a usefull trick. I would say it is most usefull on long manual lenses, like my Tokina 400/5.6. If I shoot birds or other animals with them, working speed is important. So I could use apperture priority full open, but this lens performs much better (and gives me enough DOF to fit a whole deer inside it) if I can stop down one or two stops. This trick let me do that and still meetering without the green button. I suppose one could find it usefull on fast portrait lenses also, since even if f1.4 or f1.8 sounds sexy, people usually want more than the nose to be sharp.

But say that you get hold of an old macro 50/4 all manual lens. Will this help you? Not really, because you typically have to close down a macro lens quite much to get enough DOF, and then you wont see well enough to focus...without moving the apperture back and forth, which lose you the advantage this method had to the green button. I think the same would apply if you get hold of a good old 24 or 28mm and want to use it for landscapes. You need large DOF, close it down to f11-16, and it gets very dark...

As for Canon shooters that torture good old Pentax and Takumar lenses...let's put a price on their heads

06-17-2010, 10:37 AM   #9
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I guess this is where Super/S-M-C Taks and similar lenses with an A-M switch have an advantage over the k or M series lenses. The can be used in the Av mode with the lens set to M.

I think when people deface an M or k series lens of value, they need to man-up and discount the hell out of it when they sell it. I got a k lens once that the previous owner had goobered up the auto aperture, but didn't disclose that and tried to hem-haw out of it when I got it.
06-17-2010, 10:38 AM   #10
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QuoteOriginally posted by Douglas_of_Sweden Quote
. . .

As for Canon shooters that torture good old Pentax and Takumar lenses...let's put a price on their heads
:bigthumbsup:

QuoteOriginally posted by Douglas_of_Sweden Quote
Well, nothing new with this. Last time I saw a post on this it was a dremmel also. But why do you have to be so violent? Take a screw driver, remove the mount, lift out the "little black sliding part" and the spring that will be attached to it. Put them both in an envelop, mark it with the lens name. Put the mount back and the screws. Et voilá, reversible. I've done that to some lenses temporary, most often my Tokina 400/5.6. Stepping it down one step improve the contrast and sharpness, while still bright enough to focus manually, and in this way I can shoot in Av mode. But I would never destroy a lens in this way when it is so easy to do it in a reversible way.
Exactly!
06-17-2010, 11:18 AM   #11
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The Av mode with manual lenses is just not reliable. It's not consistent even if you dial in exposure compensation. Back when I used the Av mode I spent a lot of time trying to get the correct compensation for a given stop, and still get uneven results. With the M mode you can meter once, adjust exposure for the scene and the shoot without using the green button as long as the lighting conditions are similar to the original exposure. Av is a shortcut that will cost you time and effort instead of saving it.
06-17-2010, 11:31 AM   #12
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QuoteOriginally posted by Douglas_of_Sweden Quote
Take a screw driver, remove the mount, lift out the "little black sliding part" and the spring that will be attached to it. Put them both in an envelop, mark it with the lens name. Put the mount back and the screws. Et voilá, reversible.
WORD!

Is that still current?
Tryin' to be cool here
06-17-2010, 12:05 PM   #13
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QuoteOriginally posted by Nowhere Matt Quote
I think mostly the experience is one of wanting to experiement although in the debate of using Av versus the green button, Av completely removes pushing a green button from your steps.
In Av the camera meters and sets the shutter speed as soon as your finger is gently laid on the shutter release. With the stop down method of the green button, you push the green button and then push the shutter button.
Av = push shutter button halfway then take your shot.
Green button = push green button then take your shot. See? More letters in the procedure as well.

Also in Av you have use of other in camera options including but not limited to at least the convenience of EV compensation.
unless you have
a K10 the ev compensation works, at least my IstD and k7 have ev comp in manual
06-17-2010, 12:07 PM   #14
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QuoteOriginally posted by brkl Quote
The Av mode with manual lenses is just not reliable. It's not consistent even if you dial in exposure compensation. Back when I used the Av mode I spent a lot of time trying to get the correct compensation for a given stop, and still get uneven results. With the M mode you can meter once, adjust exposure for the scene and the shoot without using the green button as long as the lighting conditions are similar to the original exposure. Av is a shortcut that will cost you time and effort instead of saving it.
Av mode is pretty good, metering in general, unless you have a K10 or K20, then I agree it is a mess
06-17-2010, 01:02 PM   #15
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Ah, well, there you go
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