The price of the SD1M is still way too high!

Started Apr 12, 2013 | Discussions thread
OP DaSigmaGuy Forum Pro • Posts: 12,304
Re: The price of the SD1M is still way too high!

Lin Evans wrote:

DaSigmaGuy wrote:

Lin Evans wrote:

Roland Karlsson wrote:

DMillier wrote:

I wonder whether an interchangeable mount is possible - a kind of modular mounting system that can be swapped out for a different mount without the use of fussy mechanical ebay adaptors?

Yes, its possible.

But ... I have a hard time seing what good that would do Sigma.

I think Pentax shall do a mirrorless camera that is compatible with K-mount via such a modular mount.

In a way, they have already done that. My Pentax Q can use K mount lenses via the Pentax K to Q adapter. In fact, that's why I bought the Q so I could connect it to a DA 55-300 and shoot at nearly 1700 mm at F/5.8..


Lin, you do know that your not actually getting 1700mm focal length and that all your actually getting is the field of view equivalent of a 1700mm lens?  Crop factor does not increase magnification, you simply get a narrower FOV for a given focal length lens.

Come on Alf - I've been at this a few years- I don't need a lesson in physics - LOL...

Let's put it this way, when I put my CP990 on my Meade ETX-90 and shoot at an "equivalent" 5989 mm I can get images not possible with "any" of my dSLR's regardless of the lens or lenses I use. To the telephoto shooter, it matters not the technicality of "how" it's done; the important thing is that it "can" be done. By the way, there is a little bit more to it than the field of view. There is the fact that the entire complement of the sensor's available photosites are vested within that tiny field of view. Try cropping a capture from a Nikon CP800E on an 800mm f/5.6 with a 2x teleconverter to the field of view of 5980mm and show me the "quality" of image you get and tell me how many pixels paint the area of the subject. Why don't you write and tell Canon to stop advertising their SX50 HS as having a 1200mm zoom. Hey, it's only a field of view thing.... Here's an example at 5980mm:


Nikon CP990 - Meade ETX -90 at 5989 mm (35mm Equivalency)

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Not sure how you worked that out Lin...The CP990 is 115mm equivalent on the long end and the Meade is 1250mm FL.  115mm + 1250mm = 1365mm equivalent, not 5980mm equivalent!

Plus you only have 3.1 million pixels to spread that FOV over...Hardly earth shattering resolution!

Then you have the problem of diffraction...The CP990 has an aperture of f4 at 115mm and the Meade has a fixed aperture of f13.8...f17.8 will give major diffraction softness, especially on a camera with 287 pixels/mm.  So not supprisingly, your pic looks very soft.

Fit that Meade on a Sigma DSLR and that would be far more interesting...I can get sharper bird shots than yours with only 230mm equivalent on my SD14:

100% crop:

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