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01-15-2013, 06:02 AM   #1
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Jello effect vs. focal length question

Just wondering: Is the "jello effect" from the electronic shutter effected by the focal length of the lens? I know it's an issue on tele lenses, but what about shorter focal lengths? I know with shorter focal lengths it's not as sensitive to camera movement due to the field of view, so I'm assuming it would help offset the jello effect. But am I assuming wrong?

I'm wondering because I'm considering picking up some C-mount lenses, all under 50mm & I'd like to be able to use them handheld.

Cheers,
Bobbo :-)

01-15-2013, 06:18 AM   #2
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I have not noticed it on my wide C mounts but that may just be luck. I just put my 4mm on and panned a room at slow 1/50 sec. and yes you can force the jello effect.

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01-15-2013, 06:29 AM   #3
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I've done a little experimenting and have come to the conclusion that you can't overcome jello with shutter speed. With my 35-105, I got the same jello at 1/8000 that I got at 1/1000 when using handheld from about 50mm on up.

I suppose I could mount my DA 18-55 to my Q & test to see at what focal length jello becomes a real problem. I might do that later today, actually.
01-15-2013, 06:43 AM   #4
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I guess that means I won't be using my Q with an adapted lens for car races or anything that is moving fast. oh well

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01-15-2013, 06:50 AM   #5
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QuoteOriginally posted by hnikesch Quote
I guess that means I won't be using my Q with an adapted lens for car races or anything that is moving fast. oh well
That's why I'm gonna have to save up for the genuine Pentax K to Q adapter with the leaf shutter. At $250, I won't be getting it for awhile, though. (Of course I also said that about the Q, so...) :-P
01-15-2013, 06:52 AM   #6
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Sounds like you are thinking about, or trying to justify the Pentax adapter.

I am curious about this also, but you are testing hand held. I will be using my Q w/adapted lenses on my tripod only with longer lenses - usually my FA* 300 4.5. Since it is winter here I haven't had the chance to really test it seriously outside. Also, because of the magnification, I doubt very much there will be any BIF shooting so when I do shoot it will be at a stationary object. I'm trying to understand the "jello" effect and what causes it. I understand that it comes from the camera using the electronic shutter instead of the leaf shutter in the Pentax adapter, but is hand holding also the cause?

I guess my question is if I should be concerned if I am mounted on a tripod shooting stationary objects.
01-15-2013, 07:02 AM   #7
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QuoteOriginally posted by hnikesch Quote
I guess that means I won't be using my Q with an adapted lens for car races or anything that is moving fast. oh well

Hans
Not to mention trying to get focus on something moving that fast.
You do seem to have mastered the art of hand holding adapted lenses on the Q so I don't put it past you
01-15-2013, 07:07 AM   #8
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QuoteOriginally posted by stormtech Quote
Sounds like you are thinking about, or trying to justify the Pentax adapter.

I am curious about this also, but you are testing hand held. I will be using my Q w/adapted lenses on my tripod only with longer lenses - usually my FA* 300 4.5. Since it is winter here I haven't had the chance to really test it seriously outside. Also, because of the magnification, I doubt very much there will be any BIF shooting so when I do shoot it will be at a stationary object. I'm trying to understand the "jello" effect and what causes it. I understand that it comes from the camera using the electronic shutter instead of the leaf shutter in the Pentax adapter, but is hand holding also the cause?

I guess my question is if I should be concerned if I am mounted on a tripod shooting stationary objects.
No reason to be concerned on a tripod for stationary objects.

The primary issue is that the sensor shutter turns off lines sequentially so any difference in position of the object, whether you or it moved, will be shown on the resulting image in a different spot on the capture.

01-15-2013, 07:14 AM   #9
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QuoteOriginally posted by crewl1 Quote
No reason to be concerned on a tripod for stationary objects.

The primary issue is that the sensor shutter turns off lines sequentially so any difference in position of the object, whether you or it moved, will be shown on the resulting image in a different spot on the capture.
Thanks Larry. Your explanation is what I needed to fully understand why this happens.
01-15-2013, 07:16 AM   #10
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Something else to consider: the Pentax adapter employs the leaf shutter at all speeds below 1/1000 sec.

The leaf shutter is larger in the adapter than on the 01/02/06 lenses so the little 'click' you hear when you shoot those lenses is a much louder 'clack!' On the adapter.

If you need absolute silence you should use the 3rd party adapter.
In my case I also use 2 sec timer on the tripod and haven't bothered to disable the sound so my shots sound like 'Beep Beep Beep Beep CLACK!'
01-15-2013, 07:31 AM   #11
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QuoteOriginally posted by stormtech Quote
Sounds like you are thinking about, or trying to justify the Pentax adapter.
Believe me, I'm not at all crazy about spending $250 on an adapter. But I do want to be able to handhold my K lenses up to 100mm on the Q. If there were any other way to accomplish that, I would go the cheaper route.

As it is, I'm still gonna wait a few months & see if the price drops. I can't imagine a huge throng of people will be lining up to buy a $250 adapter.

QuoteOriginally posted by crewl1 Quote
In my case I also use 2 sec timer on the tripod and haven't bothered to disable the sound so my shots sound like 'Beep Beep Beep Beep CLACK!'
When I did the adapted lens tests, the BEEP BEEP BEEP about scared the crap outta me. It's frickin' LOUD.
01-15-2013, 08:14 AM   #12
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QuoteOriginally posted by GibbyTheMole Quote
Believe me, I'm not at all crazy about spending $250 on an adapter. But I do want to be able to handhold my K lenses up to 100mm on the Q. If there were any other way to accomplish that, I would go the cheaper route. .
I hand hold my 200mm quite easily as long as the subject isn't moving too much. The Eye cup LCD hood really helps. I build a shoulder brace but it didn't make the trip to Florida, forgot, oops getting old. I use SR on continuous and try to shoot at 1/400 sec. or faster and get about 15% keepers. Once I get a bird in my sights I just take a lot of images, some they move some it's me and some are good. I haven't noticed any Jello on subjects that are not moving fast.

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01-15-2013, 08:16 AM   #13
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QuoteOriginally posted by crewl1 Quote
You do seem to have mastered the art of hand holding adapted lenses on the Q so I don't put it past you
Thanks Larry, like I said above I get about a 15% keeper rate, you only see the best

Hans
01-15-2013, 08:46 AM   #14
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QuoteOriginally posted by hnikesch Quote
I hand hold my 200mm quite easily as long as the subject isn't moving too much.
You're a better man than I, Gunga Din... I've gotten off & on jello from 50mm on up. The more mm's, the lower the keeper rate. And I thought I was a pretty steady handholder. I routinely shoot with a 500mm lens on a DSLR handheld with no problem.

I did get the viewfinder loupe, and you're right, it does help.

Last edited by GibbyTheMole; 01-15-2013 at 08:53 AM.
01-15-2013, 10:52 AM   #15
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Upon further testing today, I took several handheld shots of vertical & horizontal lines at each focal length 10mm apart from 18 to 105mm without using the viewfinder loupe for steadiness, and I get 90% jello-free shots up to 105mm. The longer you go the more jello you get, but even at 105mm only one of the several had noticeable jello.

So the good news is I don't have to rush into the spendy Pentax K adapter. :-)
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