Aperture settings for maximum sharpness.

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anindya49

Member
Hi, what is the smallest aperture which can be used on a HMC-150 (or in general any 1/3" camera) without any loss in sharpness? I have read a few posts suggesting f/5.6-8. Is this correct?

I am shooting some test clips to check this, but would appreciate any comments. Thanks!
 
By smallest, do you mean the smallest number? (open) or the smallest aperture? (closed)

The f5.6-11-ish is the sweet spot for just about every lens, so anytime you stray from that it will generally lose sharpness gradually as you get further towards the extremes, and so it's best to avoid having the apertured closed or open all the way.

Closing down all the way is easily avoided with your ND filters, but sometimes in low light you need to open up all the way to get proper exposure. Better to have a little softness rather than an underexposed image.
 
the smaller the opening, the sharper the focus/image.
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Not true for small-pixel HD cameras! There is a point where diffraction starts to kick in and the images start to get softer the more you stop down the lens.

On an HMC150 you're safe with any single-digit aperture (meaning, f/1.6 down to f/9.5); once you hit double-digits you start running into diffraction. The effect isn't massive, it's a mild softening, but I'd still say to stick with single digits.

Wide-open is a little bit softer than when stopped down a little, but again, the difference is pretty minimal. I don't worry about wide-open, the only aperture restriction I stick to is to keep it in single digits.
 
averan said:
then you're not making any sense.
the smaller the opening, the sharper the focus/image.
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Yes, up to a certain point, when the lens will start to suffer from diffraction, also causing softness.

Edit- I see Barry filled in with my missing info.
 
Thanks for the suggestions and yes, I was asking about the smallest usable aperture (highest f-number) with no diffraction-induced softening. Barry, I'll try to stick to single digit f-numbers.

I had one more question - does the focus ring support manual override while in autofocus mode? I noticed that it is possible to rotate it in af mode, unlike the zoom ring which is locked in servo mode.
 
anindya49 said:
I had one more question - does the focus ring support manual override while in autofocus mode? I noticed that it is possible to rotate it in af mode, unlike the zoom ring which is locked in servo mode.
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It kinda does. However, the AF sort of fights you. It changes focus one way right when you manually focus another. If you plan on manual focus, just leave it on MF
 
a compromise, set it to MF, but press the little AF button for instances when you can't be bothered.
 
Thanks, I am using manual focus. I was just curious since the manual does not mention anything about this.

The manual focus is wonderful. Even though I don't have much experience with manual video cameras, I am able to focus very quickly with the assist function. In some respects it's even easier than focusing on my DSLR, which I also use in manual mode most of the time.
 
It's just a bit awkward for me when handholding. I've never been able to put my hands in that position. Gets way too shaky sometimes -_-

I've actually debated going with a Ff for that.
 
heyrobert said:
It's just a bit awkward for me when handholding. I've never been able to put my hands in that position. Gets way too shaky sometimes -_-
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Maybe a shoulder mount will help (?)

I have also experienced this while trying out some rack focus shots. However, generally speaking, the camera is well designed ergonomically. Moving up from my HF200, not having to go into the menus for every little adjustment is great.
 
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