[Ed Hurst]

This forum often discusses our wish list for future releases, and one thing that often comes up is the desire for a new super wide. The frequently stated view is something like 'a 20mm would be great, or even wider, and I am happy for it to be slow to keep the size and cost down'.

A very sensible opinion, which I partly share. After all, daylight landscape shots don't need fast lenses, but would benefit from a high resolution super wide.

BUT...

One use that I make of my lovely 645Z is astrophotography, which benefits from wide angles, shortish exposures and wide apertures. Good though the camera is at ISO6400, which is what I need to keep exposures no longer than 20 seconds (to avoid star trailing on Milky Way shots) when shooting at f4, how I wish I could shoot at ISO 3200 by using an f2.8 lens. Noise is much better at that ISO. However, an f2.8 super wide angle doesn't exist for the system, which is what those shots need. Pumping up to 6400 wipes out some of the benefit of the camera compared to FF options, where f2.8 @ 3200 is available.

You might say this application is niche or not the territory of medium format, but this sort of shot is increasingly popular and, with the mass appeal (relatively) of the 645Z, I only partially agree.

So, how about it? A 20mm f2.4 lens anyone, massive and pricey though it would be!

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Last edited by Ed Hurst; 02-18-2016 at 07:36 PM.

[bpv_UW]

Or perhaps we'll eventually see the Sigma 20/1.4 Art in K-mount?...

[Lacunapratum]

I bite for the 20mm part of it. 22mm. Still a feat for medium format. I can't imagine f/2.8. F/4 would still be huge and super expensive.

[2351HD]

For the same price as that proposed lens you could buy a new K-1 and 15-30 and have change left over. Use Astrotracer on the K-1 and away you go.

Or you could follow Michael from Luminous Landscape and get an Astrotrack for your Z and use the 25mm on it.

[Ed Hurst]

But I don't want a tracker because I want the elements in the scene that I set against the sky to be sharp, so the camera has to be static...

It's true that i could achieve this with my D800E (or buy a A7iiR or D810, etc.) but wouldn't it be cool to do it with a medium format camera?

---------- Post added 02-19-16 at 04:30 PM ----------



---------- Post added 02-19-16 at 04:45 PM ----------

Am having some difficulty on my iPhone getting images to embed, but these should show the sort of thing I mean, where a tracker won't help:

https://www.flickr.com/photos/16063951@N00/25085229785/in/photostream/

https://www.flickr.com/photos/16063951@N00/24967069992/in/photostream/

[Digitalis]

Or perhaps we'll eventually see the Sigma 20/1.4 Art in K-mount?

We are discussing medium format here, so 1) the Sigma 20mm f/1.4 is 35mm glass - it can't cover the 645Z sensor. 2) the 645 has a significantly longer flange than any 35mm camera and thus: it would be impossible to focus the sigma 20mm f/1.4 at infinity... which is a critical requirement for this kind of photography.

I bite for the 20mm part of it. 22mm. Still a feat for medium format. I can't imagine f/2.8. F/4 would still be huge and super expensive.

Indeed a 20mm f/2.8 for the 645Z would be impractically large, especially if you're expecting it to have zero coma. Though a 22mm f/4 fisheye would be more practical.

But I don't want a tracker because I want the elements in the scene that I set against the sky to be sharp, so the camera has to be static

Hello, have you ever heard of PHOTOSHOP?

[Ed Hurst]

Yes..

[gavincato]

beautiful shots Ed

As much as I'd like the 645z to do this, I really think this is a case where you use the right tool, and the 35mm options are pretty impressive in that area.

[Ed Hurst]

Thanks mate. By the way, those ARE 645z shots. I just wish they were taken with a lower ISO ;-)

[goatsNdonkey]

Ed, if an astronomy buff can't wish for pie in the sky, who can? I say you should keep on wishing for that lens you want.


I was wondering if you have tried a longer-than-20mm f/1.4 lens for shots like this, just to see how low you can go with the ISO and how much less noise you can get that way? Obviously, you wouldn't be able to get the panoramic breadth you like, but if you included something literally grounded in the frame -- some horizon line, mountain side, building roof line, skyline, or such -- the image might still have some of the depth (in light years) you want to embrace in these images.


I am guessing that the reference to Photoshop was intended to steer you toward discovering what it might be able to accomplish in reducing the noise in those very high ISO shots.

[Ed Hurst]

Hello mate

Thanks for that. I am pretty sure that there are no f1.4 lenses of any length that can be used on the 645 system sadly, with the fastest lenses (other than a telephoto) being f2.8.

As for Photoshop, I already engage in quite sophisticated noise reduction, but of course there are still limits and shooting on a lower ISO would help. And if the earlier reply was referring instead to overlaying static objects in post on top of a star shot taken with a tracker, that's possible of course, but I would rather get the result without such compositing if possible.

Many thanks,
Ed

[Digitalis]

And if the reply was referring instead to overlaying static objects in post on top of a star shot taken with a tracker, that's possible of course, but I would rather get the result with such compositing if possible.

I do that kind of stuff regularly, even commercially with green/blue screen photography you have to know how to composite - or at least make things as easy for the compositors/re-touch artists as possible.

This is four sequential images blended together:


Pentax K5IIs - Sigma 18-35mm f/1.8 ART @21mm ISO 160 f/4 30s

I can sympathize with the ideal of getting it all done in camera in one shot, it was how I was taught - but you have to realize that there are some styles of photography that are so niche that there is never going to be a magic bullet solution that is going to make everything easier. As things are we are already capable of photographing things with a degree of quality was impossible to achieve 40 years ago.

[Ed Hurst]

You're probably right... If I was being completely unreasonable, I would have suggested an 18mm f1.4 for 645, but I was hoping that there might be enough people as silly as I am to make a 20mm f2.8 possible. But then I am no lens engineer, so there it is. Just enthusiastic musing really.

Nice shot by the way. With this shot, I had to layer several frames together, but there was no 'cutting out' of objects to place on top of another - just several frames shot from the same vantage point layered on top of one another, much as might have been done with a single longer exposure. But then i digress!

[IMG][/IMG]

[Digitalis]

You get better lightning storms in Sydney, In Adelaide we are lucky to get three of them in a year.

If I was being completely unreasonable, I would have suggested an 18mm f1.4 for 645

If you dropped a lens like that on your foot you would certainly feel it.

[bpv_UW]

We are discussing medium format here,

My mistake - clicked directly to this thread from the homepage and didn't realize was in the MF forum...

(slinks out)