Do optical zooms 15X or higher reduce image quality?

[Guest]

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I'm looking to buy my first camcorder and I like the idea of an
optical zoom in the 20X or greater range, but I'm wondering how a high
zoom factor effects the image quality. I will be using the camcorder
on a tripod so shake is not an issue. My budget is roughly $600. Are
there any issues I should look out for when choosing a camcorder with
a large zoom factor?

 

[Guest]

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On Sun, 11 Sep 2005 09:36:47 GMT, HS Crow <nomail@please.com> wrote:

>My budget is roughly $600. Are there any issues I should look
>out for when choosing a camcorder with a large zoom factor?

Sure. Given your budget, it will be a lens which will not be very
light-sensitive, and the further you zoom in, the worse it gets.
If you would want a lens with that zoom-range, having a constant maximum
aperture of say f2.8, it would set you back a nice Mercedes

cheers

-martin-
--

"Beer is life!"

 

[Doc]

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"HS Crow" <nomail@please.com> wrote in message
news:9lu7i1l0t9teh61ngidqa8cbgi71v6afig@4ax.com...
> I'm looking to buy my first camcorder and I like the idea of an
> optical zoom in the 20X or greater range, but I'm wondering how a high
> zoom factor effects the image quality. I will be using the camcorder
> on a tripod so shake is not an issue. My budget is roughly $600. Are
> there any issues I should look out for when choosing a camcorder with
> a large zoom factor?

These huge "digital zoom" numbers you see listed on camcorders are complete
snake oil, just like the massive magnification numbers listed on consumer
telescopes. I don't have the numbers in front of me but there's a
mathematical limit to the magnification a given optical instrument can
yield. You can't continually magnify ever larger an image that's coming
through a given lens. My Sony TRV-240 Digital8 has 25x optical zoom and
theoretically has 700x digital zoom, but from what I can see, the digital
zoom is a complete waste of circuitry. Even at the higher end of the optical
zoom you lose image clarity. When you get into the digital zoom it gets
nothing but worse. Looking at the moon fully zoomed in, you can't even
discern what you're looking at. It's just a big white field with fuzzy grey
blotches at points.

 

[Guest]

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On Sun, 11 Sep 2005 09:36:47 GMT, HS Crow <nomail@please.com> wrote:

>I'm looking to buy my first camcorder and I like the idea of an
>optical zoom in the 20X or greater range, but I'm wondering how a high
>zoom factor effects the image quality. I will be using the camcorder
>on a tripod so shake is not an issue. My budget is roughly $600. Are
>there any issues I should look out for when choosing a camcorder with
>a large zoom factor?

There are many issues to check out besides zoom factor, especially if
your budget is limited. So, make a list of the features that are most
important to you, including zoom, and find the camera that best meets
those features. Use the zoom to break any ties you may find.

Anyway, here's a camera that may be of some interest to you:

Panasonic PV-GS35. It has a 30x optical zoom, S-video connector
(out), mic input, accuate color (see Videomaker October issue), 1000x
digital zoom (although I don't generally recommend using digital
zoomes) etc.

NOTE: I have a "Shopping Quick-Help" section on my Digital Photography
page, so you may want to give that a look. It may help you figure out
with features: http://www.halowe-graphics.com/photo.html

Okay the price for the GS35 is $500 USD, but you should be able to
find it for less.
=PAN]http://www.pricegrabber.com/search_attrib.php/page_id=47/vendors[]=PAN

B&H lists sells it for $429.95, but there are better prices. Make sure
to check out the seller ratings before ordering (anything).

Hope this has been helpful and best of luck on your search!

Hal Lowe

http://www.halogos.com (logo t-shirts, mugs, etc.)
http://www.halowe-graphics.com/photo.html (digiPhoto)
http://www.1and1.com/?k_id=7391019 (web hosting)
http://www.halowe-graphics.com/tinc?key=0TmhZVQ5&formname=web_email

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

Thanks for the replies.
I should have stated that the optical zoom figure is of course not the
only factor that I'm basing my purchasing decision on. Also, I'm
completely ignoring the digital zoom factor as I'm aware of their
serious limitations.
I was going to buy a lower-end 3CCD Panasonic (GS120, GS75), which
typically have a 10X zoom. But, because I want to experiment with
very close-up nature shots, I figured a larger zoom ratio might be
very useful. I did notice that the Panasonic GS35 has a 30X zoom, has
had pretty good reviews and is in my price range.
I guess it's a case of I won't know the answer until I buy something
and try it out.
I suppose I was concerned that a 30X zoom on a $500 camcorder might
not be that useful, if the lens isn't up to it!

 

[Guest]

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"HS Crow" wrote ...
> Thanks for the replies.
> I should have stated that the optical zoom figure is of course not the
> only factor that I'm basing my purchasing decision on. Also, I'm
> completely ignoring the digital zoom factor as I'm aware of their
> serious limitations.
> I was going to buy a lower-end 3CCD Panasonic (GS120, GS75), which
> typically have a 10X zoom. But, because I want to experiment with
> very close-up nature shots, I figured a larger zoom ratio might be
> very useful.

Not necessarily. Sounds like MACRO ability is more important
to you than large magnification at long distance.

 

[Guest]

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>Not necessarily. Sounds like MACRO ability is more important
>to you than large magnification at long distance.

I hear you, but some of the things I want to shoot aren't so
accessible, hence I thought the need for a zoom. What sort of
distances do MACROS allow you to shoot from?

 

[Guest]

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"HS Crow" wrote...
> >Not necessarily. Sounds like MACRO ability is more important
>>to you than large magnification at long distance.
>
> I hear you, but some of the things I want to shoot aren't so
> accessible, hence I thought the need for a zoom. What sort of
> distances do MACROS allow you to shoot from?

Some can focus as close as an inch. Some can
almost focus on their own front glass! Of course
when you get that close, lighting is a problem.

 

[Guest]

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On Mon, 12 Sep 2005 12:08:13 GMT, HS Crow <nomail@please.com> wrote:

>>Not necessarily. Sounds like MACRO ability is more important
>>to you than large magnification at long distance.

In that regard, you might probably be better of with a doubler.

cheers

-martin-
--

"Beer is life!"

 

[Jimmy]

Archived from groups: rec.video.desktop (More info?)

HS Crow wrote:
>> Not necessarily. Sounds like MACRO ability is more important
>> to you than large magnification at long distance.
>
> I hear you, but some of the things I want to shoot aren't so
> accessible, hence I thought the need for a zoom. What sort of
> distances do MACROS allow you to shoot from?

What are you using for a lens now? You can get a set of close-up lenses
that will get you as close as you want and will fit a lens you already have.

 

[Guest]

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"Richard Crowley" wrote ...

> Some can focus as close as an inch. Some can
> almost focus on their own front glass! Of course
> when you get that close, lighting is a problem.

Focus "distance" is measured from the *sensor* (film or chip surface), not
the lens front.

FYI, my Sony TRV-240 will (in the absence of anything else to focus on)
focus on the surface dust on the UV filter screwed onto the front of it's
lens!

--
Richard Amirault N1JDU
Boston, MA, USA Go Fly A Kite

 

[Guest]

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"Richard Amirault" wrote ...
> Focus "distance" is measured from the *sensor*
> (film or chip surface), not the lens front.

This does not appear to be a universal standard.

 

[Guest]

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On Mon, 12 Sep 2005 20:28:33 -0400, "Jimmy" <JimmyCliff@Spamex.com>
wrote:
> What are you using for a lens now? You can get a set of close-up lenses
>that will get you as close as you want and will fit a lens you already have.

I don't currently have a camcorder, I'm asking a few questions here to
help me choose my first model, see initial post for details.

How does the add-on lens thing work? Can you add a close-up lens to
most camcorders in the $500+ range? Do they tend to be proprietary?
What sort of price range are the low to mid price lenses? It's a
whole new world to me.

 

[Guest]

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"Richard Crowley" <rcrowley@xpr7t.net> wrote in news:11idqp1v5sd7a9
@corp.supernews.com:

> "Richard Amirault" wrote ...
>> Focus "distance" is measured from the *sensor*
>> (film or chip surface), not the lens front.
>
> This does not appear to be a universal standard.
>

It is in fact the official standard in photography.

For that very reason, many cameras (not necessarily the least
professional) have a mark on the body to help you locate the film
plane.

The mark is a circle with a line through it. The line is coplanar with
the film plane.

HTH,
Gino

--
Gene E. Bloch (Gino)
letters617blochg3251
replace the numbers by "at" and "dotcom"

 

[Guest]

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"Gene E. Bloch" wrote ...
> "Richard Crowley" wrote :
> >> "Richard Amirault" wrote ...
>>> Focus "distance" is measured from the *sensor*
>>> (film or chip surface), not the lens front.
>>
>> This does not appear to be a universal standard.
>
> It is in fact the official standard in photography.
>
> For that very reason, many cameras (not necessarily the least
> professional) have a mark on the body to help you locate the film
> plane.
>
> The mark is a circle with a line through it. The line is coplanar with
> the film plane.

Apparently "shooting distance" means film-plane to subject, and
"working distance" means front-glass to subject. I was thinking
of "working distance" because it sometimes isn't clear exactly
where the "film-plane" actually is in small camcorders.

Thanks for the clarification.

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

"Richard Crowley" <richard.7.crowley@intel.com> wrote in
news:dg7pl5$ssu$1@news01.intel.com:

> "Gene E. Bloch" wrote ...
>> "Richard Crowley" wrote :
>> >> "Richard Amirault" wrote ...
>>>> Focus "distance" is measured from the *sensor*
>>>> (film or chip surface), not the lens front.
>>>
>>> This does not appear to be a universal standard.
>>
>> It is in fact the official standard in photography.
>>
>> For that very reason, many cameras (not necessarily the least
>> professional) have a mark on the body to help you locate the film
>> plane.
>>
>> The mark is a circle with a line through it. The line is coplanar
>> with the film plane.
>
> Apparently "shooting distance" means film-plane to subject, and
> "working distance" means front-glass to subject. I was thinking
> of "working distance" because it sometimes isn't clear exactly
> where the "film-plane" actually is in small camcorders.
>
> Thanks for the clarification.

Thanks for *your* clarification!

For _practical_ reasons, obviously the working distance is the
important one - especially in extreme macro modes, since it can be
pretty hard to get that picture of the mosquito or whatever, when
you've only got a few millimeters of clearance to deal with. Not to
mention not knowing where the film plane is. And besides that, no
one is really measuring these days - we're focussing by eye or by
autofocus...

Gino

--
Gene E. Bloch (Gino)
letters617blochg3251
replace the numbers by "at" and "dotcom"

 

[Jimmy]

Archived from groups: rec.video.desktop (More info?)

HS Crow wrote:
> On Mon, 12 Sep 2005 20:28:33 -0400, "Jimmy" <JimmyCliff@Spamex.com>
> wrote:
>> What are you using for a lens now? You can get a set of close-up
>> lenses that will get you as close as you want and will fit a lens
>> you already have.
>
> I don't currently have a camcorder, I'm asking a few questions here to
> help me choose my first model, see initial post for details.
>
> How does the add-on lens thing work? Can you add a close-up lens to
> most camcorders in the $500+ range? Do they tend to be proprietary?
> What sort of price range are the low to mid price lenses? It's a
> whole new world to me.

I have for example, a 50mm lens that has threads on the front where the
lens cover goes. Most lenses have these for filters. This is also where you
would attach the close-up lens set. It can be one or more that would give
you a combined magnification factor of each lens. They come in sets like
1,2,4 where you can combine to get from 1 to 7. Others sets are available.
Google for 1,2,4 close-up lenses.

 

[Guest]

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"HS Crow" <nomail@please.com> wrote in message
news:9lu7i1l0t9teh61ngidqa8cbgi71v6afig@4ax.com...
> I'm looking to buy my first camcorder and I like the idea of an
> optical zoom in the 20X or greater range, but I'm wondering how a high
> zoom factor effects the image quality. I will be using the camcorder
> on a tripod so shake is not an issue. My budget is roughly $600. Are
> there any issues I should look out for when choosing a camcorder with
> a large zoom factor?

I have a D8 (TRV-320) that I use for videoing rock climbers, 25x zoom,
bloody awesome with inbuilt image stabilization.

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

Pete D wrote:

> You have got to be kidding, my TRV-320 see the moon superbly, must be
> something wrong with your machine.

The poster was refering to the digital zoom function, which is a
pretty useless concept. Full optical zoom with the cheap lens system of
the 320 is going to cause some provlem, but obviously not serious for
your purposes.

Dave

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

"Doc" <docsavage20@xhotmail.com> wrote in message
news:WOUUe.10177$9i4.2264@newsread2.news.atl.earthlink.net...
>
> "HS Crow" <nomail@please.com> wrote in message
> news:9lu7i1l0t9teh61ngidqa8cbgi71v6afig@4ax.com...
>> I'm looking to buy my first camcorder and I like the idea of an
>> optical zoom in the 20X or greater range, but I'm wondering how a high
>> zoom factor effects the image quality. I will be using the camcorder
>> on a tripod so shake is not an issue. My budget is roughly $600. Are
>> there any issues I should look out for when choosing a camcorder with
>> a large zoom factor?
>
> These huge "digital zoom" numbers you see listed on camcorders are
> complete
> snake oil, just like the massive magnification numbers listed on consumer
> telescopes. I don't have the numbers in front of me but there's a
> mathematical limit to the magnification a given optical instrument can
> yield. You can't continually magnify ever larger an image that's coming
> through a given lens. My Sony TRV-240 Digital8 has 25x optical zoom and
> theoretically has 700x digital zoom, but from what I can see, the digital
> zoom is a complete waste of circuitry. Even at the higher end of the
> optical
> zoom you lose image clarity. When you get into the digital zoom it gets
> nothing but worse. Looking at the moon fully zoomed in, you can't even
> discern what you're looking at. It's just a big white field with fuzzy
> grey
> blotches at points.

You have got to be kidding, my TRV-320 see the moon superbly, must be
something wrong with your machine.

 

[Guest]

Archived from groups: rec.video.desktop (More info?)

Doc wrote:

> I can see the moon fine at moderate levels of optical zoom, but at max.
> digital zoom it looks exactly as I've described. No amount of focus seems to
> rectify it. If you claim you can get a sharp picture of the moon's surface
> at maximum digital zoom which I assume is 700x just like the TRV-240/530

Of course you can't. If you have say 15X optical zoom and digitally
boost it to 700, that is a factor of about 47. So max digital zoom
would be presentimg about 2 X 2 pixels at full screen.

The only systems that can make sense of that sort of blow up, are the
magical enhancements they use in TV crime drama. There, from security
camera tape, they zoom in untill they can read the perps social
security number froim a card in his wallet. In the real world, you
don't get something for nothing.

Dave

 

[Doc]

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"Pete D" <no@email.com> wrote in message
news:jo8We.47749$FA3.44105@news-server.bigpond.net.au...
> > Looking at the moon fully zoomed in, you can't even
> > discern what you're looking at. It's just a big white field with fuzzy
> > grey
> > blotches at points.

> You have got to be kidding,

I do?

> my TRV-320 see the moon superbly, must be
> something wrong with your machine.

I can see the moon fine at moderate levels of optical zoom, but at max.
digital zoom it looks exactly as I've described. No amount of focus seems to
rectify it. If you claim you can get a sharp picture of the moon's surface
at maximum digital zoom which I assume is 700x just like the TRV-240/530
models, go ahead and post it on some freebie webspace and show us how great
it looks.