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01-05-2012, 11:59 AM   #1
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issues with old lenses on k-x

Hey everyone, I've got a few quick questions about using older, M-series (amongst other) lenses on a k-x and I haven't been able to find an answer after reading over a lot of the forum.

The first is once I attach the lens and turn the camera on, it asks me to input the focal length of the lens. What do I do if it's a zoom lens? Does it even make that much of a difference? (Specifically, I am using the M 35-70mm f2.8 lens... which I guess would make it an approx. 50-105mm digital).

Secondly, I've taken a few indoor photos and the green button doesn't want to set the shutter speed at anything less than 1/20 of a second; sometimes that's long enough, sometimes it isn't. I can always alter the shutter speed in M setting, and I'm assuming this 1/20 limit is some factory setting... any way to change it though?

Thanks for any responses!

01-05-2012, 12:15 PM   #2
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QuoteOriginally posted by innivus Quote
Hey everyone, I've got a few quick questions about using older, M-series (amongst other) lenses on a k-x and I haven't been able to find an answer after reading over a lot of the forum.

The first is once I attach the lens and turn the camera on, it asks me to input the focal length of the lens. What do I do if it's a zoom lens? Does it even make that much of a difference? (Specifically, I am using the M 35-70mm f2.8 lens... which I guess would make it an approx. 50-105mm digital).

Secondly, I've taken a few indoor photos and the green button doesn't want to set the shutter speed at anything less than 1/20 of a second; sometimes that's long enough, sometimes it isn't. I can always alter the shutter speed in M setting, and I'm assuming this 1/20 limit is some factory setting... any way to change it though?

Thanks for any responses!

For the zoom, just input the focal length that you use the most for that shooting session. In doubt , set the median. Also, don't convert FL, just use the one shown on the length.

If it sets to 1/20 it's because it 'thinks' that's enough, it has nothing to do with factory setting. Try this, cover your lens with the cap or your hand then press the green button, I'm sure the shutter speed will be much slower than 1/20
01-05-2012, 12:53 PM   #3
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First problem: Outdoors you might as well deactivate shake reduction, since if it's not set at the correct focal length with a zoom lens it can induce unsharpness in the image viewed at full size.
Second problem: Increase ISO, open aperture, get lens with wider aperture.
01-05-2012, 02:14 PM   #4
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I'll just deal with SR and MF zooms: As mentioned, you can switch SR off, or set SR to the exact FL you will be using. Forget the crap.factor; if you're using a 35-70 @35mm, enter 35mm. A lens does not change its FL just because you've moved it to another camera.

You can also apply an algorithm based on the minimum and maximum FLs: INP= (2*MIN*MAX) / (MIN+MAX). I use a spreadsheet to track my lenses, and I have this formula in cells for all my MF zooms. Then I take the calculated number and put a Dymo tape label on each zoom so I know what FL to input to the SR'bot. Easy-peasy.

01-05-2012, 06:10 PM   #5
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QuoteOriginally posted by RioRico Quote
I'll just deal with SR and MF zooms: As mentioned, you can switch SR off, or set SR to the exact FL you will be using. Forget the crap.factor; if you're using a 35-70 @35mm, enter 35mm. A lens does not change its FL just because you've moved it to another camera.

You can also apply an algorithm based on the minimum and maximum FLs: INP= (2*MIN*MAX) / (MIN+MAX). I use a spreadsheet to track my lenses, and I have this formula in cells for all my MF zooms. Then I take the calculated number and put a Dymo tape label on each zoom so I know what FL to input to the SR'bot. Easy-peasy.
geez rico, that spreadsheet really does do everything!

I'll agree with what everyone else says, and mention that if your focal length doesn't exist on the options i tend to select a SR under rather than over. For eg, I have a 60-300. 60 isn't an option in the ranges. so i set it at 55.

In general though i haven't noticed a specific correlation between the FL i set and the images that result. I probably am not looking close enough or remember exactly what FL the lens was set at etc. Often I'll just accept a blurry pic as user error rather than SR failure.

Good luck with your shooting!
01-05-2012, 07:55 PM   #6
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Thanks for all the responses... very helpful for a noob.

And Rico, aren't spreadsheets awesome?
01-05-2012, 08:17 PM   #7
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QuoteOriginally posted by innivus Quote
And Rico, aren't spreadsheets awesome?
The two basic killer apps for home computers have been 1) spreadsheets and 2) email. Wikipedia came later (the killer app for Google) but spreadsheets came first and did the most to convince people to bother with these "TV-typewriters". And that's history.
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