Pentax 645D Release Date

I think that remains to be seen, but you're probably right.

I've said it before and I'll say it again. I'd like to think that the new back will fit old 645's as many of us with old 645's and lenses (both manual focus and AF) can't afford a new £5000.00 / £6000.00 camera but a back only might be affordable. I'm sure if it fits then Pentax would make a lot of money from old film 645 users. Does anyone else have any thoughts along these lines. CHEERS Vic.

Wishful thinking "I'd like to think that the new back will fit old 645's". It's a bit like the interchageable digital back idea for 35mm camera's that only Leica produced. If Pentax did that, they would not sell as many new units. But, IF they did that, it would shake the rest of the industry. A bold move indeed!

Regards

Can't see it ever happening Vic; The vast majority of that price is in the sensor which would cost the same whether fitted to a whole body or to a removeable back, hence if the camera (645D) were to cost £6000 then the back only would probably be in the region of £5500+ - I couldn't see it being a particularly big seller personally.

On paper there might be truth in that, in actual use I think it's a lot harder to tell. The design of the particular sensor also plays a large part.

Certainly a bigger sensor will give more freedom when controlling depth of field, but a typical shot in good light and at a medium aperture (once printed) would be tricky to distinguish whether it came from medium format, APS-C or even a compact sensor.

I think Pentax is wise to skip the 24x36 "full frame" format, they're a comparatively small company after all and the differences between APS-C and 24x36 are minimal at best. If you're going to make a bigger sensor then it may as well be a jump in size that can actually make a real difference.

I doubt I'll afford a 645D but I can't wait to see some results from one.

I still can't understand why I would want to use my old FF lenses on a FF pentax, they just wouldn't cut the mustard. The edge deffinition would not be good enough for the demands of a FF sensor. I get much better quality using them on APS-C where the sweet spot covers more of the field of view.

I was thinking in terms for large prints, billboards etc as well as pixel density.

Pentax will never make sensors. Money is not there for them to start doing so. They buy them in, so why not use the FF Sony sensor?

Nikon don't make sensors, they just show Sony how to use them properly.

Regards

I never considered my Pentax glass to be so lacking.

Anyone else think that we use "non mustard cutting" glass?

50 ASA slide film still out resolves a FF sensor. So why did we never hear that Pentax optics were soft at the edges.

Digital has a lot of sins to answere to.

Regards

The problem lies in the angle the light from film lenses strikes the sensor at.

Are you meaning cropped or FF sensor. If FF, then I'm confused.

Regards

Any sensor. Film lenses allow light to exit at an angle towards the edges. This strikes film just fine, but pixels are in small pits on the sensor and the light scatters on the edge of the pits instead of hitting the pixel straight on.

A digitally designed lens has a telecentric design that makes sure light exits as close to 90 degrees as possible.

The edges of a film lens aren't used by an APS-C sized sensor, so this isn't so much of a problem. A Full Frame sensor could have a problem with some lenses.

I mean FF. Sensors require the light to strike at right angles and DA lenses are designed to do that. The light from old film lenses stikes at an angle at the edges of the frame. On APSC sensors this isn't a problem.

However, the sensor on the new Leica M9 is of a radically different construction since the problem is even more acute with rangefinder lenses
so it isn't insurmountable I suppose.

Agree with John & Ken's comments.
These issues have plagued 5D users already
One design (think it was Leica) correct it by adjusting the microlens array that sits on top of the CCD. The microlenses on the edges are slightly offset to compensate for the angle of incidence.

Even the K20D reportedly improved things by semiconductor changes to the CMOS sensor. The photosites were positioned closer to the surface so the "pits" were not as deep as other sensors.

So, yes, it's a problem. And yes, it can be worked around.
And yes, it costs money

Matt

OK, all points accepted gentlemen.

So I have to assume that the Sony FF that Nikon use in the D700 has been "tweaked" to suit 35mm lenses as the images from my 12-24 on the D700 are razor sharp, edge to edge.

I now need a sort out as I kept hanging on to a lot of lenses waiting for FF from Pentax.



Regards gentlemen.

Nope, the other way around.

The Nikon 12-24 is a full frame lens but one designed in the digital era - hence it transmits light evenly across a large frame. If it had been a film era design then you would have seen quite radically different results.

If Pentax were to launch a "Full Frame" sensor then they would really need a new range of lenses to go with it - just like Nikon and Canon users have discovered. This is another reason why all your old Pentax glass is best served by an APS-C sensor

While I have no particular interest in FF, it is interesting to note that Nikon swore blind for years that they would never go beyond the DX format.

It remains pointless to speculate on what will be produced in a year or two years. If Pentax had a full frame K1 on the board right now it would be foolhardy of them to say so, since all you full frame fanatics would wait for the K1 rather than buy a K7, and the rest of us would wait for the K1 to come out and push down the price of the K7.