Re: Hyperfocal distance
- From: "Neil Harrington" <not@xxxxxxxxxx>
- Date: Sun, 4 Dec 2005 19:27:26 -0500
"Don" <mackie.don@xxxxxxxxxxx> wrote in message
news:_vvkf.10670$ea6.6813@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Thanks for your comments. Changing the conversion rate to 1.0 so there is
> no calculation for the FOV issue still raises the strange issue of the
> output of (now) of 61.8 ft.
Yes. As in your original example, there is something drastically wrong
there. The hyperfocal distance is obviously located somewhere between near
focus and infinity, and the far focus cannot possibly be located somewhere
way short of the hyperfocal distance.
> The 30.0 lmm is evidently to cater for the relevant COC given the 1.6 FOV
> issue (read the instructions further). The issue here is to be able to
> manually set the focus point on the lens given a set 50mm lens at F4 so I
> can know what will be the in and out focus range. If I read it write what
> the calculation is telling me is that at the settings I will have an
> "acceptable" range/dof of between 4.6 & 5.4 ft and if I wish to set for
> hyperfocal I would focus at 61 feet and then have an acceptable focus from
> 30 ft out to infinity? Does this seem right?
It's self-contradictory. If you have a DoF of 4.6 to 5.4 feet, then obvously
you are not focused on the hyperfocal distance, but on something near 5
feet. If your hyperfocal distance is at 61 feet and you're focused on that
then yes, your DoF is from 30.5 feet to infinity. In that case, what's the
relevance of the 4.6 and 5.4 feet business?
And yes, your DoF does need to be adjusted for the 1.6 focal length
multiplier, since the degree of final enlargement (which also affects DoF)
will be greater than if you were using the same 50mm lens on a 24x36 format.
Neil
>
> regards
>
> Don.
> "Darrell" <spam@xxxxxxx> wrote in message
> news:8-edneo7m-t4_Q_eRVn-tg@xxxxxxxxxxxxx
>>
>> "Don" <mackie.don@xxxxxxxxxxx> wrote in message
>> news:lKrkf.10500$ea6.991@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>>> Guys
>>>
>>> I am practicing up for an upcoming wedding shoot and have been looking
>>> at the issue of hyperfocal distances for some of the after ceremony
>>> shindig.
>>> I downloaded a program called Depth of Field 3 as it can work on my PDA.
>>> When setting up the calculation I set the following and press calculate:
>>>
>>>
>>> 50mm focal length
>>> 5.6 f stop
>>> 30.0 LMM resolution
>>> focus at 5 FT
>>> teleconvertor 1.6 (for the fov on my 20D canon, - hope this is correct
>>> or should I use 1?)
>>>
>> There is no 1.6 teleconverter, leave that out. The lens stays a 50mm the
>> image is merely cropped by around 40%. THis is like making an 8x12" print
>> from 35mm negative, and then cutting out a 5x8" print from the middle.
>>
>>
>>
>
>
.
- References:
- Hyperfocal distance
- From: Don
- Re: Hyperfocal distance
- From: Darrell
- Re: Hyperfocal distance
- From: Don
- Hyperfocal distance
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