From: Vance on
On May 15, 10:55 am, R Davis <spaml...(a)anon.com> wrote:
> On Sat, 15 May 2010 13:46:00 -0400, nospam THE TROLL
>
>
>
>
>
> <nos...(a)nospam.invalid> wrote:
> >In article <jkmtu5t6rjim2jvu44uc7c67d5rct7m...(a)4ax.com>, R Davis
> ><spaml...(a)anon.com> wrote:
>
> >> >The only advantage is smaller size and cost. The DSLR can always stop
> >> >down for the same DOF.
>
> >> No it can't.
>
> >yes it can
>
> >> Unless you can increase the ISO enough or use longer shutter speeds.
>
> >which it can
>
> >> The
> >> 2-3 stop noise-free advantage of ISO in a DSLR doesn't equal the 4-5 stop
> >> aperture advantage of a P&S lens at long focal lengths.
>
> >there is no 4-5 stop advantage in a p&s lens
>
> >> For
> >> macro-photography, tele-macro methods on a P&S camera can't be beat. Longer
> >> shutter speeds might require a tripod, whereas a P&S camera can be used
> >> hand-held under the very same light conditions due to the larger apertures
> >> available at long focal lengths.
>
> >increase the iso, keep the shutter speed the same.
>
> >> Stopping down your lens will also increase diffraction artifacts. A P&S
> >> lens can do the same DOF with the lens wide open.
>
> >bigger pixels on the bigger sensor nullifies that one.
>
> >> You really don't have much experience with any of this, do you. That fact
> >> has been adequately reflected in every image you've ever posted.
>
> >nor do you
>
> Nospam, it's already been proved time and time again that you've never even
> held one camera in your whole lifetime. You only parrot what you read from
> other equally ignorant trolls like yourself. Your comment about bigger
> pixels and diffraction only confirms this, yet again.- Hide quoted text -
>
> - Show quoted text -

You are so entertaining when you try and sound like you know
something, or have experience. You become absolutely hilarious when
you post pictures.

How about showing us something, like Seeker's idea of an Orange and a
glass of Orange juice? You know the conditions. Oh, I forgot. You
have:

1. No talent.
2. No skill beyond what your P&S can do - it's smarter than you, but
not smart enough for a shot that requires manual control and a
knowledge of photography and how light behaves.
3. No aesthetic sense worth mentioning.

I can understand your reluctance to try a shot, especially since I am
so much better than you will ever be, but come on, try. How will you
ever become better than a happy snap crapshooter if you don't push
your boundaries? It's how all of that are better than you got to
where we are.

Here, Sparky, I'll go first. Single light source - direct sunlight
through a window with a diffuser and a front bounce - and the
photoshopping was sharpen and getting rid of the skewer that held the
Orange and the tube feeding the Orange juice. This shot can certainly
be done with a P&S if you know something about actually making an
image and getting it right in the camera. I have even included an
image of the basic generic lighting setup.

http://picasaweb.google.com/Vance.Lear/ForTrolls?feat=directlink

You'll love this, since you go on and on about the photographer being
the key. This shot was done to show an amateur that they didn't need
to buy a DSLR and fancy lighting to turn out a good and imaginative
image. Their P&S, a Canon A590 IS, could turn out great pictures.
Don't you just love it?

Anyway, you have something to shoot for and while not the easiest shot
in the world, it's not complicated. Everything flows from knowing how
the subject behaves in light and how to get the light to behave the
way you need it to. Of course, with all of your claimed experience
and implied professionalism, you will immediately be able to see how
it all comes together and nail the shot. Yeah, right.

Keep up the entertainment.

Vance
From: Bruce on
On Sat, 15 May 2010 09:55:43 -0700, Paul Furman <paul-@-edgehill.net>
wrote:

>Bruce wrote:
>>
>> It does no harm to remind DSLR users that their choice of equipment
>> brings with it several drawbacks. In particular, macro work with an
>> APS-C or full frame DSLR can be difficult because of the extreme lack
>> of depth of field.
>>
>> In macro work, a smaller sensor offers genuine advantages because of
>> the greater of field that is available.
>
>The only advantage is smaller size and cost. The DSLR can always stop
>down for the same DOF. If you always want to be stopped down like that,
>no need for the larger camera.


Yes, but stopping down with a DSLR has the consequences of a slow
shutter speed that makes a tripod more essential. With a small sensor
camera you can still hand hold it.


>> The same guy also had a useful contribution to make recently when we
>> were discussing cleaning DSLR sensors. Putting aside his perfectly
>> valid point that compact P&S and bridge cameras don't need their
>> sensors cleaned, he pointed out that some methods of cleaning DSLR
>> sensors could induce a static charge on the sensor causing it to
>> attract dust.
>
>That was BS.


I phoned a materials scientist friend who confirmed it. He's a
university professor at a Russell Group research university - the
nearest equivalent to your Ivy League. He thought it would make a
good final year project for an undergraduate student.


>It's probably possible some combination of materials could
>create troublesome static but I tried the masking tape idea the other
>day and it worked fine.


On a sensor?


>> I found his contribution useful and constructive.
>
>The intent was destructive, as usual. That would be fine to say: "watch
>out, tape might cause static" but he said: "it won't work, you're an idiot".


Quite a few people posting here have a similar mentality, including
some who accuse him of being a troll.


>> It caused me to consider different methods of sensor cleaning for the
>> Kodak DCS Pro 14n I recently bought, whose sensor is a dust magnet.
>
>What methods?


I tried the paint-on goo we discussed a couple of weeks ago. It
seemed to work reasonably well on the rear LCD, so I tried it on the
sensor. To be honest, using it on the sensor was pretty terrifying. I
am clumsy at the best of times but I was particularly nervous because
of the risk of getting the liquid where it shouldn't go. So I didn't
cover the whole sensor.

It wasn't much fun and I won't be using it again. For someone more
confident, more skilled and less clumsy, it might be OK, but I
wouldn't recommend it to anyone I like. ;-)

From: nospam on
In article <ivvtu5pct712ku0n9h6npe8j37ik5tbkke(a)4ax.com>, Bruce
<docnews2011(a)gmail.com> wrote:

> >> In macro work, a smaller sensor offers genuine advantages because of
> >> the greater of field that is available.
> >
> >The only advantage is smaller size and cost. The DSLR can always stop
> >down for the same DOF. If you always want to be stopped down like that,
> >no need for the larger camera.
>
> Yes, but stopping down with a DSLR has the consequences of a slow
> shutter speed that makes a tripod more essential. With a small sensor
> camera you can still hand hold it.

raise the iso so that the shutter speed remains the same. the dslr has
less noise since it has a larger sensor, and by raising the iso, you
end up with the same image quality as the smaller sensor, with the same
depth of field.
From: Bruce on
On Sat, 15 May 2010 12:15:33 -0500, Kyle Abhams <where(a)what.net>
wrote:

>On Sat, 15 May 2010 06:59:27 -0700 (PDT), DanP <dan.petre(a)hotmail.com>
>ignorantly trolled everyone with the following stupidity:
>
>>
>>No, I do not think of camera design at all.
>>Instead I think of binoculars and telescopes where the bigger lens
>>diameter gives a better IQ.
>
>To edify the DanP-Troll's learning experience:
>
>In telescopes, yes. Because those lenses and mirrors are figured to
>diffraction-limited quality. You will not gain any image quality with
>diameter increase unless your optics are figured to diffraction-limited
>precision. With errors in the total curvature across the whole surface
>usually less than 1/10th the average wavelength of light. Some even
>consider that error too much and strive for 1/20th or 1/50th a wavelength
>of light. Since the objective in telescopes is comprised of only one
>element (or single group, as in the case of an achromat), this makes having
>that quality available at a price that is affordable--but still very
>expensive.
>
>In binoculars, no. The extra steps needed to figure lenses and prisms to
>that quality (where diameter means an increase in resolution, light-grasp
>yes, resolution no) would put all binoculars outside of the financial
>reach of every average consumer. The amount of magnification used in
>binoculars doesn't warrant it--considering that human eyesight resolution
>is all that will receive the image, with hand-held image shake thrown in
>for good measure too. (Except for the few that digi-scope with binoculars.)
>
>In larger camera lenses for sensors with large photosites, no. Again the
>price to bring them to the quality where larger diameter will afford more
>resolution (diffraction-limited) would put them outside of the range of any
>purchaser. Just one 90mm achromat alone could cost upward of $500 if made
>to diffraction-limited quality. Now imagine that cost multiplied by how
>many elements are in most modern DSLR lens designs. With each surface of
>every individual lens element requiring figuring to that precision. Any
>figuring errors away from absolute perfection also being multiplicative.
>Errors in one lens surface exacerbated by errors of the next. The size of
>the photosites matters too. Since they are large there's no need for mating
>them with diffraction-limited glass. Manufacturers will not take the extra
>expense involved to create a level of precision that you don't require and
>that you would never be able to detect. DSLR sensors are not like film,
>where resolutions of 2um (micron) were often the goal (the size of the
>silver grains). When all your sensors have 2um, or lesser, size photosites
>then you'll be able to tell if your lenses are of higher quality or not.
>
>This is why diffraction-limited quality lenses are made regularly for P&S
>cameras. That much resolution is required or they wouldn't be able to
>resolve details down to their ~2um size photosite levels. Their small lens
>diameters needed makes that an affordable fabrication option. The amount of
>manufacturing effort to hold a surface to a precision of 1/10th, or better,
>the wavelength of light across 30mm is relatively easy compared to trying
>to hold to that level of precision across a distance of 90mm. The effort
>(reflected in financial cost) is exponential to diameter. This is why it
>required $450,000,000 in manufacturing costs to create just *ONE*
>diffraction-limited surface across a 2.4 meter diameter area on the Hubble
>Telescope mirror.


Fascinating! Thanks for taking the time to reply.

From: Ray Fischer on
Bruce <docnews2011(a)gmail.com> wrote:
> DanP <dan.petre(a)hotmail.com>

>>No, I do not think of camera design at all.
>>Instead I think of binoculars and telescopes where the bigger lens
>>diameter gives a better IQ.
>
>Does it really? Do binoculars and telescopes really offer better IQ
>than camera lenses?

Qualified yes. Theoretical resolution for a telescope is much, much
better than a camera lens. Of course resolution isn't the only
measure of image quality.

>Can you recommend a reference where I can look at like-for-like
>comparisons?

Take a picture of the moon with a good camera lens.
Compare.

>>> Don't you mean a D3X? �The D3s is only 12 MP. �D3X has 24 MP.
>>
>>My Canon 500D has 15 MP but I use it at 8 most of the time.
>
>Why?

I use a 7D and I leave it set to 10MP. Why? Because unless I'm
shooting something that I plan to print at 20"x30", 10MP is plenty good
enough, takes up less space, and writes to the card faster.

--
Ray Fischer
rfischer(a)sonic.net