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For wide nuts! A new Zenitar/PTLens FOV test

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Hi Richard!

Thanks for the update. I already had this bad suspicion when I tried to find the Kiev Bayonet on the Arax T/S mechanism. So, the question is:
Buy it? Buy which?

The 35 is like a tilt/shift 50mm "standard", whereas the 80mm is probably closer to my tilt-macro idea I've been having for months.

Ah, well, I'll see what my LBA drives me to ;)
Jens

--
Member of LBA (Lens Buyers Anonymous), M42 section
http://www.jr-worldwi.de/photo/index.html - Photography, Tech and Geek stuff :}
'Why is everyone answering rhetorical questions?'

'90% of gear-related discussions can be summed up as 'Horses for courses' - Where do you want to ride?'
 
For those who are "only" interested in the shifting mechanism, AraxFoto offers a solution:
http://www.araxfoto.com/accessories/shift/

Cheers
Jens

--
Member of LBA (Lens Buyers Anonymous), M42 section
http://www.jr-worldwi.de/photo/index.html - Photography, Tech and Geek stuff :}
'Why is everyone answering rhetorical questions?'

'90% of gear-related discussions can be summed up as 'Horses for courses' - Where do you want to ride?'
 
Hi Richard!
richardday said:
You can do very effective shift with Photoshop, see my earlier post:
Click to expand...
I know. But you will always lose resolution, no way around it. And while I have no way of knowing, I'd guesstimate that an average medium-format lens with shift produces higher effective resolution than a good 35mm/APS-C lens with electronic perspective correction. However, being restricted to medium format focal lengths is a huge drawback for APS-C users (and still bothersome for film users).
richardday said:
.. but unfortunately you cannot do tilt control (depth of field
control etc.) in PS.
Click to expand...
Yep. One of the reasons why I'd prefer a tilt adapter - even without shift it would be useful for me.

Cheers
Jens

--
Member of LBA (Lens Buyers Anonymous), M42 section
http://www.jr-worldwi.de/photo/index.html - Photography, Tech and Geek stuff :}
'Why is everyone answering rhetorical questions?'

'90% of gear-related discussions can be summed up as 'Horses for courses' - Where do you want to ride?'
 
JensR said:
Hi Richard!

Thanks for the update. I already had this bad suspicion when I
tried to find the Kiev Bayonet on the Arax T/S mechanism. So, the
question is:
Buy it? Buy which?
The 35 is like a tilt/shift 50mm "standard", whereas the 80mm is
probably closer to my tilt-macro idea I've been having for months.

Ah, well, I'll see what my LBA drives me to ;)
Jens
Click to expand...
I have the same dilema, 80mm is more useful for flowers etc., as it gives a reasonable macro effect with the FOV and quite close focus of the 80/f2.8 lens.

The 35mm could be useful with landscape shots where you want to have tremendous depth of field control and an reasonable FOV and also larger (industrial) objects where you cannot get far enough back in the studio to fill the frame.

I think I may start off with the 80mm and see if I hit limitations and then decide to add the 35mm if neccessary.

Rgds
--
Richard Day - 'Carpe Diem!'
Gloucester UK
 
richardday said:
Eilert Ofstead said:
richardday said:
Eilert Ofstead said:
Hello Richard, interesting study.
One question: the FOV for the "77" mm window looks a lot more like
it should be for the 105mm lens, if my rough estimate of the view
is correct. Could you re-check it? I understand it gets pretty
crowded near the center of the image, and maybe the 77mm view was
left out??
Sorry if I am off base! In that case, my appologies.
Click to expand...
Hi Eilert

Take a look at my hi-res pdf, you can zoom into the areas.

http://www.zen70100.zen.co.uk/focallengths.pdf

Hope it helps
--
Richard Day - 'Carpe Diem!'
Gloucester UK
Click to expand...
Richard, thanks. The scales are much easier to see.
However..... it still seems that the field of view labeled for
77mm. is just slightly less than 1/2 of the FOV for the 50mm. view,
based on relative widths of the two boxes. Thus, in my judgement
this would be consistent with a 105mm FOV. Take another look and
see if this makes sense... ??

Eilert
Click to expand...
Hmm, see what you say. I will check them again in the morning.
--
Click to expand...
I checked them again and they are pretty accurate.

You may wish to look at the FOV angles and sizes yourself by checking them with this FOV calculator:

http://www.frankvanderpol.nl/fov_pan_calc.htm

I suggest that you set the CCD size by selecting the Nikon D70 as the size is the same as the Pentax. The VFOV is the angle you will need to compare with my table as the calculator is designed for portrait format shots.

If you then use these FOV angles to project the relative sizes of images for a given distance, you will arrive at a chart similar to mine.

Hope this explains things okay.

Regards
--
Richard Day - 'Carpe Diem!'
Gloucester UK
 
I don't get here too often so am very late to the thread, thanks Richard for the excellent illustration. Glad you've confirmed that I don't need to go looking for any other wide lens than my Zenitar, just need to find a 20mm that's a bit sharper at large apertures than my (delightfully small) "M" f4.

Gave me a big surprise to see the docks until I remembered your Gloucester address!

Cheers, Robin (from Eastington, Glos)
 
You're welcome Robin, now how about a Peleng!

I do believe that we shall see rectilinears appear that are around the 10mm focal length soon, they would be nice.

If the Sigma 10-20 is really any good and they do bring out a Pentax version, maybe that wouuld be interesting, but I hold out more hope for the Tamron 11-17, that has been quite well reviewed and would actually be a good match with the DA 16-45.

If you ever want to meet up for a photo shoot, send me a mail, my e-mail is in my profile.

Rgds
--
Richard Day - 'Carpe Diem!'
Gloucester UK
 
Thank-you for the very good presentation of this data, Richard.

I'm interested to know how many pixels (width and height) you end up with after de-fishing and cropping the Zenitar frame.

Thanks.
 
MaKeR said:
Thank-you for the very good presentation of this data, Richard.

I'm interested to know how many pixels (width and height) you end
up with after de-fishing and cropping the Zenitar frame.
Click to expand...
Hi

The de-fished and cropped (green half-tone) finished up at 3008 x 1755, the uncropped de-fished image with the shadows top and bottom (my second image) is unchanged, as is the corrected image (red half-tone) at 3008 x 2008 (the istD native size).

What does change however is the resolution of the image as the original image is both stretched and compressed due to the corrections applied.

When de-fishing an 8mm fisheye this effect is VERY noticable and you lose a very large amount of resoultion detail as well as exaggerating any abberations (CA, purple fringing etc.). This is why a proper rectilinear lens has great benefit, provided it is a quality optic.

It will be very interesting to see how well the DA 12-24 and perhaps the even wider Tamron 11-17 and Sigma 10-20 perform, if they ever make them in Pentax fit.

Another factor when shooting with a 8mm fisheye, with a view to correction later, is that the camera must be very level and avoid very close up objects (such as a face) as you will have wierd exaggerated perspectives, just as you would if you had a very wide angle rectilinear lens.

I have just updated my lens FOV chart to include 10mm, 11mm and an approximated PTLens corrected 8mm fish-eye FOV. Take a look:
http://www.zen70100.zen.co.uk/FOV_Nov_05.pdf

Rgds
--
Richard Day - 'Carpe Diem!'
Gloucester UK
 
Richard,

Just a tip with eastwave - don't know what general experience is, and I selected them after reference in this forum, but I'm still awaiting arrival in Phoenix, AZ of a Zenitar 16 shipped 10.19.05 out of Belarus through them. Their feedback is good, so assume it will arrive, just put on your patience hat.

--
Jeff B.
 
I had ordered from Victor, and had the Zenitar 10 days after I ordered it. Victor is quick.
JBBJBB said:
Richard,

Just a tip with eastwave - don't know what general experience is,
and I selected them after reference in this forum, but I'm still
awaiting arrival in Phoenix, AZ of a Zenitar 16 shipped 10.19.05
out of Belarus through them. Their feedback is good, so assume it
will arrive, just put on your patience hat.

--
Jeff B.
Click to expand...
--
My Location:
New Jersey, USA
My Profile:



 
richardday said:
photo_mom said:
Hi Richard!

Will the old Zenitar
profile work with the latest version of PTLens?
Click to expand...
Yes they do, I will send the ones I used (from Brett) across
to you later when I get home. You cann safely upgrade your
PTLens to the latest version as it will now work with 16 bit
images to give better results.
Click to expand...
Hi Richard, does the old Zenitar profile still work with the current version of PTLens? Where can one get this profile from?

Thanks,
Nick

--
Nick ( http://savoiu.zenfolio.com/ )

 
Hi Richard

Following my new thread re the Zenitar, this one cropped up from 2005. Unfortunately, the insertions into the opening post do not show up on my screen. Could you possibly repeat those?

It would seem that the PTLens software is superior to the lens correction in CS3 (which I have).

Thanks
James
 
Nick Savoiu said:
richardday said:
photo_mom said:
Hi Richard!

Will the old Zenitar
profile work with the latest version of PTLens?
Click to expand...
Yes they do, I will send the ones I used (from Brett) across
to you later when I get home. You cann safely upgrade your
PTLens to the latest version as it will now work with 16 bit
images to give better results.
Click to expand...
Hi Richard, does the old Zenitar profile still work with the current
version of PTLens? Where can one get this profile from?
Click to expand...
Yes it does, but actually there's no point, if you use the Distortion slider and then the Crop slider you end up with virtually the same result.

Sometimes you may want to keep the widest view and not use the Crop slider in PTLens, but just crop the top and bottom in PS and have a slightly more panoramic view but have a greater overall FOV, see the images in my reply to jhpatmore below.
--
Richard Day - 'Carpe Diem!'
Gloucester UK
 
jhpatmore said:
Hi Richard

Following my new thread re the Zenitar, this one cropped up from
2005. Unfortunately, the insertions into the opening post do not show
up on my screen. Could you possibly repeat those?

It would seem that the PTLens software is superior to the lens
correction in CS3 (which I have).
Click to expand...
I no longer use that server, so cannot repair the link (no long term edit facility!). So I have uploaded them to my new server:

First one.



Second one.



--
Richard Day - 'Carpe Diem!'
Gloucester UK
 
Hi Richard,

have you tried the Zenitar on the K20 ? I have not used my Zenitar for over a year , I must get it out dust it off and give it some air :-)

--
Peter
GMT+1
 
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