The A1 looks nice but..... and other reasons to keep your D7xx

GothtinPowers · Aug 7, 2003

I guess what i mean is that if the A/D can resolve a large # of greyscale 'steps', this is most useful assuming the ccd can sense a large range from light to dark...
or so it would make sense to me anyways...

GothtinPowers said:
Roland Karlsson said:

Jim Gregerson said:

Auke Nauta said:

...

Click to expand...

...

Click to expand...

You are both wrong and right regarding dynamic range.

For a pure linear A/D conversion, the maximum possible
dynamic range is determined by the number of bits. In
this case 14 bits gives 4 times the possible dynamic range
of 12 bits.

But ... 8 bit images are not linear coded ... you use
some gamma to compress the range.

Therefore, a gamma 1.8 8 bit picture, has actually a
greater theoretical dynamic range than a 12 bit
linear.

Roland

Click to expand...

miklk · Aug 7, 2003

staci said:
Do you have any specific reasons for using it so sparingly in the
cold?

I am looking to upgrade my Sony 505v this fall, and have had no
problems using it for several hours at -10F or even on the tripod
for over an hour at -20F (low-20sC).

Living in Sept-Iles (east of Montreal, Quebec, Canada), I've used my 7i many many times in cold weather (-20 to -25°C) for periods of 3-4 hours and never had problems other than with batteries (that's why I bought a powerpack).

--
mikl kacz
http://www.pbase.com/miklpb

staci · Aug 7, 2003

mikl k said:
Living in Sept-Iles (east of Montreal, Quebec, Canada), I've used
my 7i many many times in cold weather (-20 to -25°C) for periods of
3-4 hours and never had problems other than with batteries (that's
why I bought a powerpack).

By powerpack, do you mean that screws onto the bottom of the camera? I usually keep the spare batteries warm in my coat and switch out as needed. It seems if they are exposed with the camera they will die from the temperatures before you even need them.

Ideally, I would love to have an external corded battery pack that can stay inside my coat when shooting to stay at operable temps, or even away from the camera in hot weather to reduce noise.

How do you handle the camera in cold weather?

I frequently wear giant suede gloves, but I can cradle the lens of my 505v with my left hand with no worries of covering the front due to its length. The A1 seems similar to your 7i. It looks like it could easily be supported one handed. What are your experiences holding and using it with gloves or mittens? I recently purchased a walking stick with a screw top and may use that alot to support whatever camera I decide on.

Thanks for input

--
http://www.pbase.com/staci

uglyren · Aug 7, 2003

Jim Gregerson said:
Garnet,
Don't be affraid to use your D7i in the winter. Just don't keep it
out in cold for more than 1/2 hr or so depending on temp at a time
and do't let it get wet.

I'm not worried about the camera in winter. I'm worried about myself! I hate the cold!

Jim Gregerson said:
No I can't afford a DSLR - there is a big difference in $1000 US
and $3000 or more for a DSLR. Besides I really like the 28 to 200mm
lens and ease of use of the D7i.

The A1 may have it's roots in the D7 group but as far as I can see
it is a quantum leap in new technology to add to the single
carryover - that beautiful 28 to 20mm lens. I think Minolta did all
the right things to keep me from jumping to a dslr.

In my search for a good dslr I noticed, that to cover the 28 to 200
range and macro, I would have to buy 2 lenses and go through the
extra pain of changing lenses. There is that long lens range I
would like to have 400mm + but that may be only 5% of my shooting
needs - the 28 to 200 covers 90 to 95% of my needs. If I was a pro
shooting wildlife or airshows, maybe it would be different.

I see the ad conver is 14bit - this should increase the dynamac
range, probably my biggest beef. Maybe we don't really need a dslr

--
http://www.showtelinc.com/aphoto2.htm
Jim Gregerson

uglyren · Aug 7, 2003

Unless the ccd size is increased dynamic range won't really change signifigantly imho. Small photosites like those found in consumer grade ccds simply cannot handle the same DR as a dslr ccd with its much larger photsites.

GothtinPowers said:
GothtinPowers said:

Roland Karlsson said:

Jim Gregerson said:

Auke Nauta said:

...

Click to expand...

...

Click to expand...

You are both wrong and right regarding dynamic range.

For a pure linear A/D conversion, the maximum possible
dynamic range is determined by the number of bits. In
this case 14 bits gives 4 times the possible dynamic range
of 12 bits.

But ... 8 bit images are not linear coded ... you use
some gamma to compress the range.

Therefore, a gamma 1.8 8 bit picture, has actually a
greater theoretical dynamic range than a 12 bit
linear.

Roland

Click to expand...

Click to expand...

Roy Dane · Aug 7, 2003

Hi Staci
Let me try to answer your questions

staci said:
staci wrote:

By powerpack, do you mean that screws onto the bottom of the camera? Ideally, I would love to have an external corded battery pack that can stay inside my coat when shooting to stay at operable temps, or even away from the camera in hot weather to reduce noise.

When refering to the Dimage 7 / 7i / 7HI, powerpack usually refers to the Digipower DPS 9000. The DPS 9000 comes with a variety of cables, so it can be used with a large assortment of cameras ( hopefully the Dimage A1 is one of them ). You can either screw it to the bottom of the camera, or put it in a coat pocket and attach a cord to the camera. Keep in mind that the cord for the DPS 9000 is only about 8" long.

staci said:
How do you handle the camera in cold weather?
I frequently wear giant suede gloves, but I can cradle the lens of
my 505v with my left hand with no worries of covering the front due
to its length. The A1 seems similar to your 7i. It looks like it
could easily be supported one handed. What are your experiences
holding and using it with gloves or mittens? I recently purchased a
walking stick with a screw top and may use that alot to support
whatever camera I decide on.

My one longterm use of the Dimage 7i was at Whitefish Point and Taquaminon Falls in Michigan's Upper Pensinsula in early March. I spent a good 20 minutes photographing the Lake Superior shoreline and the Coast Guard station, before driving to Taquaminon Falls State Park where I spent about 3 to 4 hours outside photographing the falls ( at least the small portion of the lower falls that were open ) and some of the other scenery.

I either handheld the camera in my mittens ( changing batteries and Compact Flash cards was a real chore ) or mounted the camera on my Bogen 3021 tripod, with no problems at all. If you plan on using it a lot during the winter, I would recommend that you practice using it with your mittens on. As I said ( I didn't even practice !! ) I had no problems ( other than changing cards and batteries ) using the Dimage 7i with my mittens on.

staci said:
Thanks for input

You are most welcome
Roy

staci said:
--
http://www.pbase.com/staci

Auke Nauta · Aug 7, 2003

GothtinPowers said:
I guess what i mean is that if the A/D can resolve a large # of
greyscale 'steps', this is most useful assuming the ccd can sense
a large range from light to dark...
or so it would make sense to me anyways...

Hi fellow 'dynamic range guys',

Yes, you are correct.

The dynamic range of the sensor is the maximum light intensity difference a sensor is able to capture, irrespectfully of the A to D conversion!

Jim, Minolta and others can say what they want, but A/D conversion accuracy will not change the dynamic range of the sensor.

Obviously, it is most useful in getting the most out of that range (for instance contrast may be increased in captured detail without obvious 'stepping' using such a high bit depth (accurate) D/A conversion).

Nonetheless, I hope Minolta (Sony?) could improve the dynamic range of the sensor, as it really can be a bottleneck sometimes...

Greetings to all,
Auke Nauta

Dman · Aug 8, 2003

uglyren said:
I'm writing this partially to make D7xx owners feel better but
mainly to make myself feel better !

What does the A1 really offer you over the D7xx?

CCD IS? How do you even know if it works well? If you really
needed IS you'd have bought a DLSR with super long teles and all
that wonderful stuff. At only 200mm good technique, a tripod or
taking multiple shots in continous mode will improve your results.

Same lens. You'll still be pulling hairs out of your head trying
to find TCs, WAs and filters that work with it!!

More DOF? Some may praise the increase in DOF to F11. Sorry but
I need a decrease in DOF. You all know you'd kill for F2.0 or
lower. If I've lost you with the DOF talk then your fine with what
you have already and you should stop reading now and go out to
practice a little.

Same CCD. Some people have speculated that the CCD is not the same
because it supports a progressive scan mode but so did the Oly E20
(same sony 2/3 as D7xx) . They used it to achieve the 1/18000
shutter speed and the A1 now supports 1/16000th. Guess what
though? The E20 was limited to 2.5 mp at that shutter speed. Will
the A1 be the same?

The A1 needs a propriatary battery now. Sorry but nothing is more
convieniant than AAs. If you need more juice for your D7xx buy a
DPS 9000 and keep your AAs for backup.

I'll give it credit for faster AF. With 11 point auto focus it's
hard to argue that it will not be fast. Still judging from past
behaviour, Minolta could tweak existing D7xx AF speed with a
firmware upgrade.

Noise reduction? Easy firmware update. Besides on the rare
occasion that you actually see noise in your pictures rather than
in 100% crop examples you saw on the internet you can easily fix it
with neatimage. (Please Oracles of noise, no flaming!! )

A camera is like a lover. If you choose carefully in the first
place you should be able to maintain a long happy relationship. If
you frequently change partners you will never find true happiness.
Make a comittment and get to know your camera for awhile your
photography will only benefit.

Garnet

When D7Hi out after I brought my D7i, I was wondering how good will be the D7Hi. In the end, the changes in D7Hi over D7i aren't that great and I could relax over it and happy with my D7i.

Now, A1 is out, the specs from my views is that it aren't much different from the D7Hi. The design are mostly taken from other model (G2 n CP5000) and the functions almost the same as a 602.

I feel that Minolta using the D7 series to let users get use of their camera before they merge their D7 series with other camera design n specs. Now, users who use to D7 series and having the likes of other camera, would mostly go for A1.

I would like to see a real DSLR and not A1. Minolta A1 didn't win my $ this time. If they come out with a DSLR, I am considering about it. I would like to see a true bulb mode and not a tiny 30 secs which can't do much. A true macro and the improvement from the D7 series to A1 still the same (correct me if I am wrong) The sences mode still about the same and have not increased (maybe not important but since it was a pro-consumer, it still consider low to other) There are still a lot of CONS of getting A1 if you still own a D7i/D7Hi.

POV, if you thinking of getting a A1, I think you better save a bit more to get a true DSLR or wait for the Minolta DSLR (If there is one) A1 is for those without D7i/D7Hi and not for those who already own either one (D7i/D7Hi) I think that we shouldn't make a big fuss over the new A1 if we own a D7i/D7Hi as these 2 still consider good enough over other. ;-)

Dman

--
http://www.pbase.com/lcklzg

Jeremy Rosenberger · Aug 8, 2003

Strictly speaking, you're absolutely right about the definition of dynamic range. In the digital realm, however, the term has come to be (somewhat incorrectly) overloaded. I think this is because it's a simple matter to manipulate an image so that its histogram contains a range of values from pure black (0,0,0) to pure white (let's assume a 24-bit image and say 255,255,255). Since there is nothing more black than 0, and nothing more white than 255, in this sense all digital cameras are capable of producing the same (to misuse the term) "dynamic range." The differences then lie in how faithfully the sensor/ADCs capture slight luminance variations, and the resolution of the ADCs certainly comes into play here. Certainly a camera with 1-bit ADCs wouldn't be thought of as having great dynamic range; on the other hand, the dynamic range resonse of a camera with 32-bit ADCs would be limited by the sensor itself. Thus, although the pedantically correct definition of dynamic range would not take ADC resolution into account, I believe a definition of "effective dynamic range" would have to.

Cheers,
Jeremy

--
Jeremy L. Rosenberger
http://www.frii.com/~jeremy/

Auke Nauta · Aug 9, 2003

Jeremy Rosenberger said:
Strictly speaking, you're absolutely right about the definition of
dynamic range. In the digital realm, however, the term has come to
be (somewhat incorrectly) overloaded. I think this is because it's
a simple matter to manipulate an image so that its histogram
contains a range of values from pure black (0,0,0) to pure white
(let's assume a 24-bit image and say 255,255,255). Since there is
nothing more black than 0, and nothing more white than 255, in this
sense all digital cameras are capable of producing the same (to
misuse the term) "dynamic range." The differences then lie in how
faithfully the sensor/ADCs capture slight luminance variations, and
the resolution of the ADCs certainly comes into play here.
Certainly a camera with 1-bit ADCs wouldn't be thought of as having
great dynamic range; on the other hand, the dynamic range resonse
of a camera with 32-bit ADCs would be limited by the sensor itself.
Thus, although the pedantically correct definition of dynamic range
would not take ADC resolution into account, I believe a definition
of "effective dynamic range" would have to.

Cheers,
Jeremy

Hi Jeremy,

I totally agree with you.
Obviously there are real benefits increasing the A to D accuracy.

Yet too many people just seem to relate bit depth to dynamic range linearly, where they shouldn't.

Greetings,
Auke

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The A1 looks nice but..... and other reasons to keep your D7xx

GothtinPowers

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miklk

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staci

Leading Member

uglyren

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uglyren

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Roy Dane

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Auke Nauta

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Dman

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Jeremy Rosenberger

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Auke Nauta

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