[enricob]

Hi,

I've been using Pentax 67 for 20 years, (unfortunately) I am considering the purchase of my first digital camera and I'm also considering Pentax 645Z because it's an (quite) affordable MF camera with OVF (since I like OVF, the only alternative would probably be some FF as Nikon D850 - if I don't miss something).

All the matter is quite complicated, but I would like to ask who of you use the Pentax 645z a simple question: what's the longest shutter speed you use with this Pentax 645z freehand (55mm lens, ambient light) without any traces of (micro) motion blur, even at a 100% magnification?

The longest shutter speed I can use Pentax 67 + 90mm lens (same conditions as above) is 1/30 in case I raise up the mirror before the shot - as I usually do every time I need. The longest shutter speed I can use Nikon D850 is 1/250, perhaps 1/125. This is also because of the 3 stops difference between Pentax 67 and Nikon d850, that I would really like to know what's your experience with Pentax 645z.

What's more, is this shutter speed even longer in case you raise up the mirror of the Pentax 645z before the shot? Does it make a difference?

Thank you,

Enrico

[Unregistered User 8]

Hi Enrico, there is a very good in-depth review of 645Z linked below for you. I think it will answer most of your questions.

Pentax 645Z Review - Introduction | PentaxForums.com Reviews

[texandrews]

Hi,

I've been using Pentax 67 for 20 years, (unfortunately) I am considering the purchase of my first digital camera and I'm also considering Pentax 645Z because it's an (quite) affordable MF camera with OVF (since I like OVF, the only alternative would probably be some FF as Nikon D850 - if I don't miss something).

All the matter is quite complicated, but I would like to ask who of you use the Pentax 645z a simple question: what's the longest shutter speed you use with this Pentax 645z freehand (55mm lens, ambient light) without any traces of (micro) motion blur, even at a 100% magnification?

The longest shutter speed I can use Pentax 67 + 90mm lens (same conditions as above) is 1/30 in case I raise up the mirror before the shot - as I usually do every time I need. The longest shutter speed I can use Nikon D850 is 1/250, perhaps 1/125. This is also because of the 3 stops difference between Pentax 67 and Nikon d850, that I would really like to know what's your experience with Pentax 645z.

What's more, is this shutter speed even longer in case you raise up the mirror of the Pentax 645z before the shot? Does it make a difference?

Thank you,

Enrico

Hi, Enrico

Of course this is a person to person question. Some will be able to hold longer, and some not so long. Myself, I would trust 1/60th of a second with MLU---but I would definitely also shoot multiple frames.

But then, you also say: "...without any traces of (micro) motion blur, even at a 100% magnification?" That's a tall order. If I wanted to be absolutely sure of this, then I'd say 1/125th, MLU, and multiple frames.

I would also say, however, that it's more important to get the shot and tolerate a little "micro" blur. The deconvolution sharpening software available today is very good, so I am confident I could handle a little blur in post. So, I have shot my Z down to (I think) 1/2 a second, MLU and multi frames---this done in/at historic sites, indoors, low light, when no tripod or monopod was allowed.

But now for the excellent news: I doubt you will have much need to shoot the Z at such a shutter speed considering your experience with film in the 67. The Z's high iso capabilities are superb, and you should not be afraid to use them.

[Denver]

HI

I agree with Enrico. I use the z and handholding at lower speeds is doable. A higher ISO than 100 is excellent and enlarged well. Enjoy this wonderful camera and its many features that give you incredible pictures.

Herb

[enricob]

Many thanks Andrew for your answer.

But now for the excellent news: I doubt you will have much need to shoot the Z at such a shutter speed considering your experience with film in the 67.

What do you mean? I'm sorry, I am really ignorant in the field of digital photography.

Anyway, my usual, frequent Pentax 67 + 90mm set for freehand low light shooting is MLU, Portra 400, f4, 1/30 (motion blur with longer shutter speed).

The Z's high iso capabilities are superb, and you should not be afraid to use them.

Yes, it is very useful to know that it is possible to reach ISO values that it would be better to avoid with some other cameras.

Then of course I need time to understand if, in low light conditions, I prefer to bear the drop in quality and DOF determined by the maximum opening, or some more noise for an upper ISO value, or even the micro motion blur with a longer time.


These are the abstract considerations I'm able to do before even starting to use a digital camera. Waiting for suggestions and some more experience and opinions about the longest shutter speed you use with this Pentax 645z freehand.


Thank you,

Enrico

[Digitalis]

I use the 645Z and 645D in the studio a lot, but with mixed lighting I have hand held 1/15th, granted it was with the 90mm f/2.8 OS which is my go-to studio lens with the 645 digital system. The Pentax LS shutter lenses have fewer issues with vibration and thus can be hand held at low shutter speeds with good technique.

[UncleVanya]

Hi,

I've been using Pentax 67 for 20 years, (unfortunately) I am considering the purchase of my first digital camera and I'm also considering Pentax 645Z because it's an (quite) affordable MF camera with OVF (since I like OVF, the only alternative would probably be some FF as Nikon D850 - if I don't miss something).

All the matter is quite complicated, but I would like to ask who of you use the Pentax 645z a simple question: what's the longest shutter speed you use with this Pentax 645z freehand (55mm lens, ambient light) without any traces of (micro) motion blur, even at a 100% magnification?

The longest shutter speed I can use Pentax 67 + 90mm lens (same conditions as above) is 1/30 in case I raise up the mirror before the shot - as I usually do every time I need. The longest shutter speed I can use Nikon D850 is 1/250, perhaps 1/125. This is also because of the 3 stops difference between Pentax 67 and Nikon d850, that I would really like to know what's your experience with Pentax 645z.

What's more, is this shutter speed even longer in case you raise up the mirror of the Pentax 645z before the shot? Does it make a difference?

Thank you,

Enrico

What focal length on the D850? How are the two viewed and compared? Film scans might be a tad more forgiving than 45mp digital. Also the focal length on the d850 should be matched by crop factor to reduce the impact of the difference in the angular coverage on the amount the lens movement impacts the light falling on the film/sensor.

[enricob]

What focal length on the D850? How are the two viewed and compared?

D850 + 40 mm lens, viewed and compared on a calibrated NEC monitor at 100% magnification view.

I tried 2 different 40mm lenses, Voigtlander Ultron 40mm and Sigma 40mm Art. Since the second lens is huge and very heavy (1.2 kg) while the other one is a pancake lens, with the 40mm Sigma Art it was possible to use a little longer shutter speed, until 1 stop difference.

Film scans might be a tad more forgiving than 45mp digital.

Yes. The shutter speed I need in case of d850, it probably depend on 50mp distributed on a quite small size sensor. It is assumed that when the same amount of megapixels is distributed on the larger sensor of the Pentax 645z, the shutter speed you can use should be slower. But it is a theoretical consideration, and therefore this is why I ask 645z users about their experience.

Also the focal length on the d850 should be matched by crop factor to reduce the impact of the difference in the angular coverage on the amount the lens movement impacts the light falling on the film/sensor.

I didn't understand this, perhaps for my English, perhaps because it's complicated.

Thank you,

Enrico

[UncleVanya]

I didn't understand this, perhaps for my English, perhaps because it's complicated.

I was pointing out what you already know which was that the size of the sensor affects How easy you can hold the images steady - partly because of pixel density but also because of the distances the light traverses on the sensor due to the photographer’s movement.

[texandrews]

Many thanks Andrew for your answer.

What do you mean? I'm sorry, I am really ignorant in the field of digital photography.

Digital photography generally allows for higher iso shooting than film. Film gets ugly after iso 400 (color, at least---with B+W grain can be beautiful). With the 645Z you can shoot at 1600 and it's better than film at 400. I have shot at 6400 and been pretty satisfied---I needed to work on it in post on the computer a bit, but it wasn't a problem at all.

[enricob]

But then, you also say: "...without any traces of (micro) motion blur, even at a 100% magnification?" That's a tall order. If I wanted to be absolutely sure of this, then I'd say 1/125th, MLU, and multiple frames.

I use the 645Z and 645D in the studio a lot, but with mixed lighting I have hand held 1/15th, granted it was with the 90mm f/2.8 OS which is my go-to studio lens with the 645 digital system. The Pentax LS shutter lenses have fewer issues with vibration and thus can be hand held at low shutter speeds with good technique.

Thank you for all your answers.

What's more, how much does it change in case of shooting while you are moving? I mean, as in case you shoot while you are walking, or in case you try to take some pictures of your little son running and you too, you need moving to follow him around.

The longest shutter speed I can use Pentax 67 + 90mm lens while I'm moving, walking, without any traces of (micro) motion blur, even at a 100% magnification, is 1/250.

This is a quite frequent situation for me and some more information would be useful. May be someone has been taking pictures in a similar situation and then he experimented, he verified how the Pentax 645z work in these cases.

Thank you,

Enrico

[texandrews]

Thank you for all your answers.

What's more, how much does it change in case of shooting while you are moving? I mean, as in case you shoot while you are walking, or in case you try to take some pictures of your little son running and you too, you need moving to follow him around.

The longest shutter speed I can use Pentax 67 + 90mm lens while I'm moving, walking, without any traces of (micro) motion blur, even at a 100% magnification, is 1/250.

This is a quite frequent situation for me and some more information would be useful. May be someone has been taking pictures in a similar situation and then he experimented, he verified how the Pentax 645z work in these cases.

Thank you,

Enrico

Sorry, can't help here. I never work that way. Furthermore, everything I photograph is typically not moving (there are some exceptions...)

[TDvN57]

Thank you for all your answers.

What's more, how much does it change in case of shooting while you are moving? I mean, as in case you shoot while you are walking, or in case you try to take some pictures of your little son running and you too, you need moving to follow him around.

The longest shutter speed I can use Pentax 67 + 90mm lens while I'm moving, walking, without any traces of (micro) motion blur, even at a 100% magnification, is 1/250.

This is a quite frequent situation for me and some more information would be useful. May be someone has been taking pictures in a similar situation and then he experimented, he verified how the Pentax 645z work in these cases.

Thank you,

Enrico

I think your question might be impossible to answer, because of all the variables involved and these vary for each person. This impossible to transfer that to you.

Perhaps your best option is to "convert/translate" your experience with the 6x7 to what you can expect on the 645z.

For example find a scenario where you are satisfied the micro movements are insignificant enough for your requirement on the 6x7.

Translating that to the 645z you only really have the ISO to play with when you are talking about moving subjects. Because freezing a moment with moving subjects has only one requirement, a fast shutter speed. The shutter speed depends how steady you are holding the camera in relation to the subject, also known as panning in larger movements.

With static subjects you could perhaps lower the shutter speed by one or two stops to account for the lesser mirror slap effect of the 645z compared to the 6x7.

Coming back to the ISO, as others have also mentioned, you can comfortably shoot at 3600 iso, as long as you don't under expose. At 6400 and higher you need to get comfortable with the post cleaning up in ACR/Lightroom.

I can't tell you the difference between the Fuji 50 mpx cameras and the 645z in terms of noise at high iso, because I don't have a Fuji to compare.

I suspect the 645z raw files have less noise than the Fuji, but I could be wrong. I have found in some cases the raw DNG files, ex camera is sharper and cleaner than the png files. Other may have found different results.

Compared to the 6x7 and what I've seen of the Fuji 50mpx cameras I find the 645 system, film and digital to be much better balanced. Even with a longer and heavier lens, the system just feels right and steady. I can take a shot with my one hand without much strain, with a faster shutter speed of course. I can't speak to other systems like Hasselblad and P1 on this topic, and others may not find balance an important attribute.

Everyone rides his horse his own way, as they say.

I hope you find a solution for your problem.

[Ed Hurst]

Would this be a good moment to mention the two lenses for the 645Z that have image stabilisation? <<runs off...>>

[enricob]

Would this be a good moment to mention the two lenses for the 645Z that have image stabilisation? <<runs off...>>

I know these other two lenses but I am not interested in using these zoom and focal length.

For almost 10 years now I have been going around with Pentax 67 and always the same 90 mm prime lens, in fact the 645Z is interesting for me because it has a 55mm lens which has almost the same angle as a 90 mm 67.

Thank you,

Enrico