[2351HD]

Could the Z be given an electronic first curtain shutter via a firmware upgrade, or is it limited due to processing power or on chip hardware?

Also, a chap on the Fuji GFX Facebook site claims that because the flange distance on the Pentax is so long, that this directly affects the quality of the wide and ultra wide lenses, making them harder to manufacture and not capable of the same image quality as the short flange distance of the Fuji. I am calling BS on this. Can anybody confirm? I would have thought it was the other way around.

[Adam]

Also, a chap on the Fuji GFX Facebook site claims that because the flange distance on the Pentax is so long, that this directly affects the quality of the wide and ultra wide lenses, making them harder to manufacture and not capable of the same image quality as the short flange distance of the Fuji. I am calling BS on this. Can anybody confirm? I would have thought it was the other way around.

Could be- but the only supporting evidence I know of is Pentax abandoned the DA 25mm F4 simply because it wasn't cost-effective to produce, even at the $5000 price tag (I was told that a high % of the lenses that were produced ended up coming back due to defects).

Not sure about EFCS, but they could probably add it if they wanted to, assuming no new model is in the pipeline.

[clackers]

Also, a chap on the Fuji GFX Facebook site claims that because the flange distance on the Pentax is so long, that this directly affects the quality of the wide and ultra wide lenses, making them harder to manufacture and not capable of the same image quality as the short flange distance of the Fuji. I am calling BS on this. Can anybody confirm? I would have thought it was the other way around.

A very short flange distance is actually problematic.

In theory, you can make an UW without the retrofocal group, but I read that's not always desirable.

And being so close to the sensor (without a mirror housing), the angles are very bad away from the centre. You can get vignetting and drop off in sharpness.

Sony even tried to put in little compensating microlenses on top of the A7 sensor, which meant the extra thickness of the stack also led to smearing and magenta colour shift in the corners of UW images.

[Digitalis]

Could the Z be given an electronic first curtain shutter via a firmware upgrade, or is it limited due to processing power or on chip hardware?

It's the limits of the sensor design that are the cause here, which is beyond the ability of firmware to change.

you can make an UW without the retrofocal group, but I read that's not always desirable.

Also because the resulting lens would be massive.

[BROO]

Also, a chap on the Fuji GFX Facebook site claims that because the flange distance on the Pentax is so long, that this directly affects the quality of the wide and ultra wide lenses, making them harder to manufacture and not capable of the same image quality as the short flange distance of the Fuji. I am calling BS on this. Can anybody confirm? I would have thought it was the other way

Isn't this more a result of the sensor in the 645Z being a crop (33*44mm) of the original 645 film format?
Make it a FF MF sensor and you don't need such a short focal length to get the same FOV. (pardon me I'm no expert)

[clackers]

Isn't this more a result of the sensor in the 645Z being a crop (33*44mm) of the original 645 film format?
Make it a FF MF sensor and you don't need such a short focal length to get the same FOV. (pardon me I'm no expert)

This Fuji uses the same crop 645 sensor, Broo ...

[paulster]

Actually, on the 645Z with a larger flange distance you have to collimate the rays from a wide angle lens more than you might on a smaller flange camera to actually hit the sensor, to the angle of attack on the sensor is likely to be less, so I'm not sure this argument holds water.

[Digitalis]

a chap on the Fuji GFX Facebook site claims that because the flange distance on the Pentax is so long, that this directly affects the quality of the wide and ultra wide lenses, making them harder to manufacture and not capable of the same image quality as the short flange distance of the Fuji. I am calling BS on this. Can anybody confirm?

the problem here is that this was posted on facebook, hardly the place I would look for rational and learned discussion on photography. In a nutshell the flange distance between a lens and sensor can be as long as it needs to be - it won't affect image quality. I have used 8X10 cameras with over 900mm of bellows extension to work with some lenses [which I might add are almost as sharp as most 35mm lenses] . I have also used wide lenses on 8X10 format that needed bellows so short it would be better described as a sock. As you can see the 70.67mm flange of the 645Z is hardly earth shattering in the realm of photography.

As for lens design, yes a shorter flange makes wider lenses easier to design, the rule of the thumb is you only need to use retrofocal designs as the focal length is equal to or shorter than the flange - and any flange below 20mm gives plenty of room for fast aperture wide angle lenses [ there are optical designs that to an extent, can solve this problem: however they are complete anachronisms and would have limited appeal in this day age with the mass appeal of fast, well corrected, interchangeable AF lenses]. A shorter flange also makes certain issues such as vignetting and astigmatism much more of a headache to eliminate. Ever wondered why so many modern Leica lenses have aspheric elements in them?

[BostonUKshooter]

Could be- but the only supporting evidence I know of is Pentax abandoned the DA 25mm F4 simply because it wasn't cost-effective to produce, even at the $5000 price tag (I was told that a high % of the lenses that were produced ended up coming back due to defects).

Not sure about EFCS, but they could probably add it if they wanted to, assuming no new model is in the pipeline.

Alex Munoz (CA) posted some comparison shots between the 25mm and 28mm on the 28-45mm zoom.....the 25mm does not give that much of an increase in field of view....
The widest MF modern (prime) lens I've seen is the Phase One 28mm, which gives a f.o.v similar to 17mm on a 35mm camera....even Phase One ambassadors say that there is slight curvature of the image from this lens compared to the 35mm which is completely flat field. The only other options are the 30mm fisheyes from Hassy and Pentax 67 (+adapters) with attendant built-in distortion.

[Digitalis]

.the 25mm does not give that much of an increase in field of view....

you're missing the point a bit here, the 25mm f/4 [ at least the copy I have] can cover full 645 format, which makes the Pentax 25mm f/4 a 15mm 35mm equiv - which simply doesn't exist anywhere else in the current MF arena. It also has an internal filter drawer that makes using polarisers with such a wide lens much less of a pain.

Also you're forgetting about the Leica Super Elmar-S 24mm f/3.5 ASPH - which is one of the few Leica lenses to use fluorite elements in its design, of course this and the red dot make it expensive as hell.

[BostonUKshooter]

you're missing the point a bit here, the 25mm f/4 [ at least the copy I have] can cover full 645 format, which makes the Pentax 25mm f/4 a 15mm 35mm equiv - which simply doesn't exist anywhere else in the current MF arena. It also has an internal filter drawer that makes using polarisers with such a wide lens much less of a pain.

Also you're forgetting about the Leica Super Elmar-S 24mm f/3.5 ASPH - which is one of the few Leica lenses to use fluorite elements in its design, of course this and the red dot make it expensive as hell.

Thanks for the update and additional info on the Leica (had missed that one!)...didn't realise that the 25mm is that 'wide'.....almost on a par with the 14mm of the Nikon 14-24mm.....and I hadn't realised about the filter drawer......I read that the 25mm was 'withdrawn from sale for unspecified reasons', presumably because of the reported level of manufacturing rejects mentioned here...?.....onward and upward...

[Digitalis]

.I read that the 25mm was 'withdrawn from sale for unspecified reasons', presumably because of the reported level of manufacturing rejects mentioned here

The sales volume wasn't high enough to continue production, also there were issues of bad copies floating around. The lens was basically a sunk cost, it may re-appear later on down the line. there was a redesigned version which has a different lens hood, but that impacted the image circle - making the lens essentially a reduced format lens. The original Pentax SMC DFA 25mm f/4 Asph is a full 645 format lens.

[2351HD]

What's the calculation for the full frame 100mp sensor, is it x0.62 or something like that?

That would make a DFA35 the same as a 21 or 22mm lens?

[Adam]

What's the calculation for the full frame 100mp sensor, is it x0.62 or something like that?

That would make a DFA35 the same as a 21 or 22mm lens?

The D FA 35mm covers the full film image circle. Here's a table comparing the difference between FF and crop 645:

The Crop Factor Unmasked - Articles and Tips | PentaxForums.com

[2351HD]

Thanks Adam

Always good to have this chart on hand!

Anybody here tested the D FA 35mm on a 645 film camera to see how it goes?