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Re: [APML] Medium format camera [and piggyback]
Hi Jose...here are my photos using the Mamiya 150mm f/2.8 lens.
http://www.ruckuseffect.com/astro/mamiya645_piggyback.html
I am too new at this astrophotography thing (I started in May) to know if
these photos represent vignetting. However, when I attempted to align them
for a mosaic, I failed because the stars were more spread out on the edges
than their matching counterpart in the center of the next frame. My theory
on this is the lack of field flatness in the Mamiya 150mm lens. In May I did
a mosaic with 3 photos of the exact same area using a Nikon F3 with the
Nikon 105mm f/2.8 micro lens, which has a built-in field flattener. The
mosaic fit nicely (thanks to Jason Ware for his assistance):
http://www.ruckuseffect.com/astro/milkyway.html
-Phil
----- Original Message -----
From: "Jose Miguel Benito Huete" <jbenito1@teleline.es>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Sunday, November 09, 2003 2:03 AM
Subject: Re: [APML] Medium format cameras (was:Tak. FSQ-106 for
mediumformatfilm?)
> Phil, I have a Tak FS102 and a Pentacon six medium format camera. So far I
have
> used the camera with different lenses as a piggyback system (180mm and 300
mm)
> and it looks like the film is not completely flat on the film plane since
stars
> at the edges of ths frmae are differentially affected by distortion. I
guess it
> is very difficult to maintain a 6X6 frame on the same plane during the
> expossure. Also, with this camera some of the frames are juxtapossed. Is
this a
> flaw of all medium format cameras. I am going to move to a Kiev 88CM model
now
> and don't know if this is going to improve things.I have done a custom
adapter
> for the Tak F102 and have shot a couple of frames at f8 with the Pentacon.
They
> were good but there was some vignetting. Have you also observed vignetting
with
> the Mamiya? Finally the method I use to focus is to previously make a
focus
> test usinf a calibrated paper bar attached to the focuser of the telescope
and
> therafter that using that fixed position for all the shots. What do you
think of
> this particular method?
> Many thanks
> Jose Miguel Benito
> Madrid
> Spain
>
> Phillip Jones escribió:
>
> > Alan,
> >
> > Takahashi makes an adapter for the Mamiya 645 to work on the FS-102 and
> > FS-128. I attach my Mamiya 645 1000s to my FS-128 both with and without
the
> > Takahashi focal reducer. I also did this when I had the FS-102.
> >
> > There are several Mamiya 645 bodies to choose from. The biggest
advantage to
> > using the 1000s body is it contains a mirror lock. The only other Mamiya
645
> > body that has the mirror lock is the current model, the 645e. I have
this
> > body as well. The disadvantage to the 645e is the prism is not
removable,
> > where as it is removable on the 1000s.
> >
> > The 1000s is no longer made, but KEH.com usually has a good selection.
That
> > is where I purchased mine.
> >
> > You can see photos I've taken, as well as my 645 1000s attached as both
a
> > piggyback camera and as a prime focus camer to my FS-128 on my site:
> >
> > http://www.ruckuseffect.com/astro
> >
> > My biggest challenge with the Mamiya is focusing. The 2x diopter I
purchased
> > for the 1000s helps, but I still am off a little. Gene Horr suggested I
use
> > the Takahashi FM40 or FM60 (I just purchased the FM60), place it on the
> > focusing screen (after your remove the prism) and focus. I have also
> > heard--and I'm going to try it--that you can use the FM40 or FM60 with a
> > piece of ground glass, and place the glass where the film plane is. Of
> > course, this will work only for the first photo, or if you have a 2nd
body,
> > which I have. Should you choose to do this, you can buy a cheap body
from
> > KEH.com for this purpose.
> >
> > Let me know if you have any further questions.
> >
> > -Phil
> >
> > ----- Original Message -----
> > From: "Alan Voetsch" <critter12952@yahoo.com>
> > To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
> > Sent: Saturday, November 08, 2003 2:25 PM
> > Subject: [APML] Medium format cameras (was:Tak. FSQ-106 for medium
> > formatfilm?)
> >
> > > Hey all,
> > >
> > > The discussion between Dean and Kirk has gotten me thinking about
> > > moving up to a medium format camera. Actually I've thought about it
> > > many times, but I only now have an instrument that can utilize MF. The
> > > Tak FS-102 will be able to handle that format and once I'm comfortable
> > > with it and the new G-11 with Gemini, I would consider trying a bigger
> > > format camera.
> > >
> > > What I would like to know is if anyone has a tutorial, or such on
their
> > > website regarding this. Or barring that, can anyone give any pointers
> > > on what to look for in such a camera. The reason I ask is that I saw
> > > one advertised on astromart last week that had a purge system already
> > > installed. This camera had been used on a 102 and I assume that the
> > > user knew what he was doing. My assumption has always been that a
> > > camera body is basically just a film holder. I'll qualify that by
> > > saying that I would probably also use it for piggyback shots.
> > >
> > > All things being equal, is the camera manufacturer important here? Are
> > > there certain things to look for? To avoid? Is a Pentax 67 the wise
> > > choice in the long run?
> > >
> > > What I really want is to be pushed in the right direction so when I do
> > > have the cash for such a purchase, I hace done my homework and can
jump
> > > on it then without screwing up. At that point, I would like to know of
> > > any adapters, etc... that would be necessary. Any guidance would be
> > > much appreciated.
> > >
> > > Thanks,
> > > Alan
> > >
> > >
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