DP3M vs NEX 7

Started May 27, 2013 | Discussions
Braud Michel Regular Member • Posts: 240
Re: DP3M vs NEX 7
...... And by using a variety of lenses, I think you lose the advantage of the DP camera, which is a lens perfectly designed for and matched to the sensor......

Best regards, Sandy

For all fix lens cameras, I read this comment very often but never find any explanation as how a lens, designed for digital sensor not film of course, can be specially adapted to a sensor.

After all, any lens is made to focalize light on the sensor plane. So my question is what kind of adaptation have fix lenses that inter-changeable lenses don't ?

jennyrae Senior Member • Posts: 2,690
Re: DP3M vs NEX 7

from reading, adaptation of fix lens is that rear optic sits very close to sensor. something very difficult to do and expensive with interchangeable lens with different focal size. also read something on how rear optic construction and size is specified for camera. the idea does look to suggest to get maximum picture quality output because precision positioning of sensor for particular lens. my understanding one camera body is not only different in lens, but different also in design structure. also make camera and lens, small as possible and cheap. I think this is goal of DP merrill cameras.

if person want to use big generic lens or big sigma interchangeable lens on sigma camera, buy SD camera.

Braud Michel Regular Member • Posts: 240
Re: DP3M vs NEX 7

jennyrae wrote:

from reading, adaptation of fix lens is that rear optic sits very close to sensor. something very difficult to do and expensive with interchangeable lens with different focal size. also read something on how rear optic construction and size is specified for camera. the idea does look to suggest to get maximum picture quality output because precision positioning of sensor for particular lens. my understanding one camera body is not only different in lens, but different also in design structure. also make camera and lens, small as possible and cheap. I think this is goal of DP merrill cameras.

if person want to use big generic lens or big sigma interchangeable lens on sigma camera, buy SD camera.

Thanks for your reply, at least you took the trouble to try to expose what you think could be adjusted. The idea to have the optic very near the sensor is sensible, it should limit diffraction depending of the focal lenght, then a standard bayonnet/sensor distance might not be optimum, but I have inter-changeable lenses which protude a lot inside, so this is done. To get a significant difference I believe you must get very tight tolerances, Alpa style, which are probably not in Sigma process, nor any other big brands.

But as you do, I am only guessing, I wish to find a real technical article on the subject.

nick_webster
OP nick_webster Veteran Member • Posts: 7,623
That's just silly

Just in case you've forgotten here it is again :

This was taken with a lens designed for film over 30 years old. With the adapter the back of the lens sits at least 5cm or 2 inches from the sensor.

Perhaps you could tell me how that could possibly work ? Or show me where the flaws are, since it isn't designed for that sensor ?

Nick

EDIT : look at the wick of the red candle which is the point of focus - you can see the weave of the wick !

victorgv Senior Member • Posts: 1,663
Re: That's just silly

nick_webster wrote:

This was taken with a lens designed for film over 30 years old. With the adapter the back of the lens sits at least 5cm or 2 inches from the sensor.

Perhaps you could tell me how that could possibly work ? Or show me where the flaws are, since it isn't designed for that sensor ?

Nick

EDIT : look at the wick of the red candle which is the point of focus - you can see the weave of the wick !

As far as i understand sensors are more sensitive to angle of light than film. This why sensor for M9 had different spacing of photosites depending on distance from the center of sensor  and microlenses were alined differently  for the same reason. Another thing a few years back i read review comparing zoom lenses to prime from nikon and cannon surprisingly zoom lenses were better optical quality overall. And leica lens from 60's outperformed them. Go figure...

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nick_webster
OP nick_webster Veteran Member • Posts: 7,623
Yes, film more forgiving

The light could hit the fim grains at more oblique angles and still react, photosites need more acute angles of incident light. Lots of sensors have offset micro lenses to help with this issue.

Nick

Tom Schum
Tom Schum Veteran Member • Posts: 8,307
Re: SD1 - will it go in my pocket ?

nick_webster wrote:

There is no reason that I can see that Sigma couldn't have made a DP body and then sold the 3 DP lenses as interchangeable lenses to fit. Might have been slightly bigger to account for the mount but still considerably smaller than an SD1. It would also mean that if they develop a new sensor you don't have a body and lens to upgrade, just the body.

No the obvious answer to me is the DP ILC concept. It would actually be more pocketable as you could split the body from the lens and put the items in separate pockets as I can if I want to carry my NEX.

The SD1 also can't take a large number of lenses that a DP ILC would. eg Leica M mount - due to the long registration distance necessary to clear the swingy mirror. Lots of other lenses that would fit require modification, not something I'm desperately keen to do.

If I wanted something the size of the SD1 I'd more likely go the way of the Nikon D800 - 36MP would beat the SD1 on detail and give me the option of all of Sigmas lenses plus those of NIkon and Tamron. In addition it's a better all round SLR then the SD1 by some margin.

I found it quite shocking when I saw what Sony managed to fit into nearly the same size body - you wouldn't believe how handy an articulating LCD can be for tripod and other work - why contort your body when you can just move the LCD

If Sigma can't package a camera better I wish they'd license the sensor out to others who can,

Nick

DP ILC concept could work well with a mount large enough to hold the lenses of the DP1, DP2, or DP3, with each lens having an internal leaf shutter as found in those lenses.

As soon as we put in a focal plane shutter we start to get dust on the sensor, and then something is needed to keep the sensor clean, such as an ultrasonic shaker.  So the camera gets more expensive fairly quickly.

Also, it takes a focal plane shutter a little longer to set up and shoot a photo: First it has to close so the sensor can be cleared, then it has to expose the sensor, then it has to close again while the sensor is unloaded, then it has to open again to engage live view.  My Fuji X-E1 does this and it's fairly noisy.  Whenever I turn off the camera it cleans the sensor with a shaker for a quarter second, and this has been effective to keep dust to a minimum.

No need for a focal plane shutter if the lenses have internal leaf shutters.  But, if the lenses are interchangeable, the sensor will have to be kept clean since all lens changes allow dust into the sensor area.  So a DPxM ILC will absolutely need some sort of sensor cleaning system.

These sorts of things will boost the price of the ILC body into the range of the Fuji X-E1 but that won't be too bad.  I would love to see a Sigma ILC!

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Tom Schum

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Tom Schum
Tom Schum Veteran Member • Posts: 8,307
Re: Some rusty bolts with incredible detail, eh?

I agree about the colors.  I can't get my SD1 to give me good reds and it has the latest software too.

As a landscape or documentary camera it truly does have the best resolution at base ISO.  With the SD1 I find it is almost impossible to get good focus without focus-bracketing, and that's a lot of extra trouble.  DP3M for example will simply contrast autofocus, eliminating this issue.

Landscape and documentary uses are covered.  For the rest, I have my Fuji X-E1.

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Tom Schum

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glacierpete Senior Member • Posts: 1,917
Re: Wide angles and NEX don't mix ;-)

Nick,

The DP1M and DP2M are now $ 799 / € 615 as special at B&H.

http://www.bhphotovideo.com/c/product/878793-REG/Sigma_c78900_DP2_Merrill_Compact_Digital.html

I wonder whether Sigma will bring out a new version of the Merills?

jennyrae Senior Member • Posts: 2,690
Re: Wide angles and NEX don't mix ;-)

the same price I saw months ago. no change.

diolus Regular Member • Posts: 446
Re: Wide angles and NEX don't mix ;-)

Offer ends June 30th

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REShultz Senior Member • Posts: 1,108
Re: Some rusty bolts with incredible detail, eh?

Tom, how much better is the Foveon at low ISO than the XE-1 in your estimation?

Hornbrille
Hornbrille Regular Member • Posts: 361
Maybe these are better examples in favour of the DP3
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nick_webster
OP nick_webster Veteran Member • Posts: 7,623
I've said that all along,

The Sigma is quite limited, but when it works it works very well indeed. That is why I am hoping for a DP body that I can stick other lenses on.

An EVF or tilting LCD would also be very nice

Nick

Erational Regular Member • Posts: 184
Re: DP3M vs NEX 7

No-one seems to care about mentioning this so I might as well; the DP series flash syncs at any speed. The shadow are harsh because of the time of day?-  no problem for the DP's w flash. The NEX 7, nor many interchangeable lens cameras can do that. The Fuji X100S can flash sync at high speeds like 1/2000 too, but you have no other choice but a 23mm lens- Sigma has 3 lens lengths of camera to choose from.

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