Using hyperfocal distance on A200

Just learning both digital photography techniques & the A200 & currently looking at using Hyperfocal distance for those nicely focused landscape shots.

Having worked out a few "settings" using the DOFMASTER calculator I find that it doesn't seem possible to set the focus distance to the required figures using the A200's manual focus

Just for example -- I've chosen to calculate the figures for focal lengths of 28mm, 35mm, 50mm & 100mm, basically because they are marked on the lens

At 100mm / F5.6 hyperfocal distance is 13.71 metres but the A200 is only giving me either 10m or 20m to choose from

I'd appreciate some guidance from the very knowledgeable posters on here ???

thanks

simon

simonkit said:

Just learning both digital photography techniques & the A200 &
currently looking at using Hyperfocal distance for those nicely
focused landscape shots.

Having worked out a few "settings" using the DOFMASTER calculator I
find that it doesn't seem possible to set the focus distance to the
required figures using the A200's manual focus

Just for example -- I've chosen to calculate the figures for focal
lengths of 28mm, 35mm, 50mm & 100mm, basically because they are
marked on the lens

At 100mm / F5.6 hyperfocal distance is 13.71 metres but the A200
is only giving me either 10m or 20m to choose from

I'd appreciate some guidance from the very knowledgeable posters on
here ???

Click to expand...

Simon

If you can't set the focusing distances to those you've calculated f values for, why not do the reverse and calculate the f values for the distances you CAN select at the various marked zoom settings?

In other words, calculate what f number you'd need to set to make either 10 or 20 metres become the hyperfocal distances for 28mm, 35mm etc.

Presumably, if you've got the formula, you can swap it around to do this?
--
Peter
http://www.pbase.com/isolaverde

Isola Verde said:

simonkit said:

Just learning both digital photography techniques & the A200 &
currently looking at using Hyperfocal distance for those nicely
focused landscape shots.

Having worked out a few "settings" using the DOFMASTER calculator I
find that it doesn't seem possible to set the focus distance to the
required figures using the A200's manual focus

Just for example -- I've chosen to calculate the figures for focal
lengths of 28mm, 35mm, 50mm & 100mm, basically because they are
marked on the lens

At 100mm / F5.6 hyperfocal distance is 13.71 metres but the A200
is only giving me either 10m or 20m to choose from

I'd appreciate some guidance from the very knowledgeable posters on
here ???

Click to expand...

Simon

If you can't set the focusing distances to those you've calculated
f values for, why not do the reverse and calculate the f values for
the distances you CAN select at the various marked zoom settings?

In other words, calculate what f number you'd need to set to make
either 10 or 20 metres become the hyperfocal distances for 28mm,
35mm etc.

Presumably, if you've got the formula, you can swap it around to do
this?
--
Peter
http://www.pbase.com/isolaverde

Click to expand...

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Peter,

considered this aswell, but I think this would be difficult too as determining the focal length would be pretty difficult -- it's the reason I used the graduated markings on the lens to base my calculations on. In theory it would then be a simple case of setting the focal length to the 50mm marking, setting the aperture & then using manual focus to set the required hyperfocal distance.

This is still possible for some settings, for example 100mm / F8 = 9.75m so setting manual focus to 10M would be near enough, it's just with some other settings the margin would be 7 / 8 metres which is too much I think

thanks

simon

Simon,

With the 4x crop factor of the Axxx cameras the hyperfocal distance is not such a critical issue than it can be for full frame or smaller crop factor (D)SLR cameras, though using charts to get the figures right can be useful/ helpful/ educational, while approximation of the exact distance will do you no harm.

In your example at 100mm / F5.6 the value of 13.71 meters means everything will be in focus from half that distance to infinity, i.e from 6.855 meters.

In this case I would set the distance to 10 meters so as to get everything in focus from 5 meters to infinity (why not?). With this approximation you can't go wrong, eh?! On the other hand it's easier to judge a distance of 10 meters with our eyes that to judge a distance of 13.71 meters, isn't it?

And if you still misjudged the distance and set your camera to 12 meters you are still getting a very good result because this leads us back to the 4x crop factor of the Axxx ccd size!

And if you are still not convinced you can always set your camera to 10 meters, compose the landscape fix all your settings and before hitting the shutter release just take two steps backwards.

Happy shooting!

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

Ferenc MOGOR said:

Simon,

With the 4x crop factor of the Axxx cameras the hyperfocal distance
is not such a critical issue than it can be for full frame or
smaller crop factor (D)SLR cameras, though using charts to get the
figures right can be useful/ helpful/ educational, while
approximation of the exact distance will do you no harm.

In your example at 100mm / F5.6 the value of 13.71 meters means
everything will be in focus from half that distance to infinity,
i.e from 6.855 meters.

In this case I would set the distance to 10 meters so as to get
everything in focus from 5 meters to infinity (why not?). With this
approximation you can't go wrong, eh?! On the other hand it's
easier to judge a distance of 10 meters with our eyes that to judge
a distance of 13.71 meters, isn't it?

And if you still misjudged the distance and set your camera to 12
meters you are still getting a very good result because this leads
us back to the 4x crop factor of the Axxx ccd size!

And if you are still not convinced you can always set your camera
to 10 meters, compose the landscape fix all your settings and
before hitting the shutter release just take two steps backwards.

Happy shooting!

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music.
Ansel Adams.'

Click to expand...

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Thanks Feri - guess I was looking at things a little too "technically", one of the problems with being an engineer !!

I'm just waiting for some sunshine to appear here in the UK so I can get out & try all these new ideas

simon

One more question has just sprung to mind -- they just keep coming !!

When using Hyperfocal distance is it still the case that DOF principles apply - small aperture / WA

If so would setting WA at 28mm with F10 & manual focus at 0.6m hyperfocal distance produce an even sharper image than simply using aperture mode ??

simon

It is always the aperture that controls the depth of field, it does not matter what mode the camera is in. f/8 at 28mm (35mm eqv) will always give the same depth of field for a given focusing distance no matter what mode you are in. f/11 at 28mm with the same focusing distance will give more depth of field.

--
When you've got a moment, have a look at my site:
http://www.wrightphotos.co.uk

Winner of the South West Rural section of the BBC's Picture of Britain Competition.

Greg

Staxis said:

It is always the aperture that controls the depth of field, it does
not matter what mode the camera is in. f/8 at 28mm (35mm eqv) will
always give the same depth of field for a given focusing distance
no matter what mode you are in. f/11 at 28mm with the same
focusing distance will give more depth of field.

--
When you've got a moment, have a look at my site:
http://www.wrightphotos.co.uk

Winner of the South West Rural section of the BBC's Picture of
Britain Competition.

Greg

Click to expand...

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That's what I thought Greg - in which case what's the advantage of using hyperfocal distance, is it mainly for use when you have a subject / object in the foreground ??

simon

Don't forget that F6 to F7 tends to give the sharpest images on the Ax lens. F9 and onwards can be very soft

Cheers
Steve

simonkit said:

That's what I thought Greg - in which case what's the advantage of
using hyperfocal distance, is it mainly for use when you have a
subject / object in the foreground ??

Click to expand...

Yes! Focusing at the hyperfocal distance gives you the maximum depth of field for a given aperture. If you focus at infinity with a 28mm lens your depth of field is tiny compared with using the hyperfocal distance. As you have seen, with your camera you can get everything from a few meters away to infinity in focus if you use the hyperfocal technique.

To summarise, focusing on a distant subject will not give you the maximum depth of field. If you want to maximise depth of field, it is often better to focus closer, at the hyperfocal distance.

--
When you've got a moment, have a look at my site:
http://www.wrightphotos.co.uk

Winner of the South West Rural section of the BBC's Picture of Britain Competition.

Greg

Staxis said:

simonkit said:

That's what I thought Greg - in which case what's the advantage of
using hyperfocal distance, is it mainly for use when you have a
subject / object in the foreground ??

Click to expand...

Yes! Focusing at the hyperfocal distance gives you the maximum
depth of field for a given aperture. If you focus at infinity with
a 28mm lens your depth of field is tiny compared with using the
hyperfocal distance. As you have seen, with your camera you can
get everything from a few meters away to infinity in focus if you
use the hyperfocal technique.

To summarise, focusing on a distant subject will not give you the
maximum depth of field. If you want to maximise depth of field, it
is often better to focus closer, at the hyperfocal distance.

--
When you've got a moment, have a look at my site:
http://www.wrightphotos.co.uk

Winner of the South West Rural section of the BBC's Picture of
Britain Competition.

Greg

Click to expand...

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Thanks again Greg - I haven't yet tried using Hyperfocal distance, only had the camera 3 weeks, I've only used Aperture mode, generally around F8 - I've been very impressed with those shots so looking forward to trying some more using Hyperfocal distance, if only the weather would sort itself out !!

simon

...

1. sweet point
2. diffraction

To make a long story short, the "sweet point" of the Axxx series GT Minolta lens is said to be at or around f5.6 aperture value. You may do a search on this forum with the above keywords, this issue has been beaten to death a couple of times.

As regards "diffraction" this is the reason why it's not really worth to use the GT lens above f5.6 for landscapes coz this lens phenomenon will cause certain distortion (by limiting the resolution of the optical system) in your images resulting in loss of sharpness. More scientific approach is here: http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

So, as a conclusion: If you want to keep your images sharp, don't use f11 with Minolta GT lens. The effects of diffraction will be clearly visible at f11 and significantly degrade the image. Use f11 only if you have no choice.

Remark: in landscape photography please do not confuse diffraction and haze. Diffraction is a physical parameter of the optical system of your camera while haze is an atmospheric enemy of us photographers.

Always go out on a so-called "perfect day" when the weather is at it's best, no overcast skies just a couple of puffy clouds appear in the sky, you know for decoration(!), and believe it or not even the day of the week can make a significant difference. Whaddaya think is the best day of the week when all the above circumstances are available? I prefer Sundays! Coz on that day even the industrial pollution in the sky is at it's lowest, unfortunately not nil, but just the lowest. Again not to be confused with haze! ;-)

FYR, here's a sample shot taken on that kinda perfect day in Budapest on a Sunday morning:



--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

Like you I'm waiting for the weather. When I have time to take pictures the sky is grey. When I'm at work the sun comes out! And I have so many ideas at the moment. Frustration.

Best of luck, and don't forget to post your results here.

--
When you've got a moment, have a look at my site:
http://www.wrightphotos.co.uk

Winner of the South West Rural section of the BBC's Picture of Britain Competition.

Greg

Thanks guys for the responses. Just to summarise the thread then:

Best aperture for sharpness in F5.6

Best option for DOF is hyperfocal distance in Manual mode

therefore according to the "Hyp Dist" calculations I made (adjusted to suit the A200's manual options) & the advice of the posters here, I'll be using these settings for landscape shots as they should provide best combination of DOF & sharpness (please let me know if anyone disagrees with these !!)

28mm focal length @ F5.6 = 1 metre hyp dist

35mm focal length @ F5.6 = 1 metre hyp dist

50mm focal length @ F5.6 = 4 metre hyp dist

100mm focal length @F5.6 = 10 metre hyp dist

I guess images at F7.1 should be pretty sharp too:

28mm focal length @ F7.1 = 1 metre hyp dist

35mm focal length @ F7.1 = 1 metre hyp dist

50mm focal length @ F7.1 = 3 metre hyp dist

100mm focal length @F7.1 = 10 metre hyp dist

I'll post the results when the weather gives me chance !!

If anyone wants to give them a try please do & post the results

thanks

simon

simonkit said:

Thanks guys for the responses.

Click to expand...

If I'm one of the guys, then: not at all, t'was my pleasure!

simonkit said:

Just to summarise the thread then:

Best aperture for sharpness in F5.6

Click to expand...

True! In the full dof range!

simonkit said:

Best option for DOF is hyperfocal distance in Manual mode

Click to expand...

Oooops! Hyperfocal distance does not care about your camera mode! It's only related to the optical system of your camera, independent of whatever your mode is!

simonkit said:

therefore according to the "Hyp Dist" calculations I made (adjusted
to suit the A200's manual options) & the advice of the posters
here, I'll be using these settings for landscape shots as they
should provide best combination of DOF & sharpness (please let me
know if anyone disagrees with these !!)

28mm focal length @ F5.6 = 1 metre hyp dist

35mm focal length @ F5.6 = 1 metre hyp dist

50mm focal length @ F5.6 = 4 metre hyp dist

100mm focal length @F5.6 = 10 metre hyp dist

I guess images at F7.1 should be pretty sharp too:

28mm focal length @ F7.1 = 1 metre hyp dist

35mm focal length @ F7.1 = 1 metre hyp dist

50mm focal length @ F7.1 = 3 metre hyp dist

100mm focal length @F7.1 = 10 metre hyp dist

Click to expand...

Just a question here. Why do you want to shoot landscapes at 100 mms? Won't it be too narrow a focal length? OK, I dunno, always depends on the given circumstances!

simonkit said:

I'll post the results when the weather gives me chance !!

Click to expand...

Lookin' forward asap!

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

Ferenc MOGOR said:

Just a question here. Why do you want to shoot landscapes at 100
mms? Won't it be too narrow a focal length? OK, I dunno, always
depends on the given circumstances!

Click to expand...

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Feri,

your correct of course - chances are that I won't use 100mm focal much, if at all

I just calculated the values based upon the focal length markings on the A200 lens - makes life easier for me !!

thanks

simon

What Resolution (lines/mm) did you use? This greatly affects the calculations.

simonkit said:

Ferenc MOGOR said:

Just a question here. Why do you want to shoot landscapes at 100
mms? Won't it be too narrow a focal length? OK, I dunno, always
depends on the given circumstances!

Click to expand...

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.
Feri,

your correct of course - chances are that I won't use 100mm focal
much, if at all

I just calculated the values based upon the focal length markings
on the A200 lens - makes life easier for me !!

thanks

simon

Click to expand...

My Dear Mr. Engineer (aka Simon),

Just for relaxing,...why not calculate it again for 10,000 mms as well, eh? Just kidding! LOL

Me also engineer, but with feet on the ground, though sometimes head in the cloulds, no way out for us!!! ))

Sleep tight! ;-)

--
Cheers, Feri

'I can look at a fine photograph and sometimes I can hear music. Ansel Adams.'

Ferenc MOGOR wrote:
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Ferenc MOGOR said:

My Dear Mr. Engineer (aka Simon),

Just for relaxing,...why not calculate it again for 10,000 mms as
well, eh? Just kidding! LOL

Me also engineer, but with feet on the ground, though sometimes
head in the cloulds, no way out for us!!! ))

Sleep tight! ;-)

Click to expand...

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Hmmmm - now theres a thought Feri, 10,000mms eh ??

-- very tempting, can't help myself - which I could leave my head at work sometimes & swap it for a "normal" one !!!

speak again sometime

thanks

simon

You probably don't need to calculate it at 10,000mm, because it will be sooooo small (but you can check if you must!).

How about calculating it for macro distances instead? With the CL49-200, DOF seems like fractions of a mm at closest focus distance! Do you know if there is a way to get DOFmaster to go below 35cm?

Mike