10 X and noise suppression

[Les]

Archived from groups: rec.photo.digital (More info?)

A friend is using his old Oly 2100 for researching the optics of 300
year old telescopes. The required exposures are long enough to cause
quite a bit of noise in his images. He has rigged an adapter of his own
design to give him a reasonable image size on the 2100 and thinks he
needs to stay with 10X. What camera would you recommend??

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Canon 1Ds Mk II



les wrote:
> A friend is using his old Oly 2100 for researching the optics of 300
> year old telescopes. The required exposures are long enough to cause

> quite a bit of noise in his images. He has rigged an adapter of his
own
> design to give him a reasonable image size on the 2100 and thinks he
> needs to stay with 10X. What camera would you recommend??

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Cannon 20D with a t-ring and a 2" focuser adapter

I don't understant the "researching the optics of" part. Is your
friend using the camera to take pictures of the diffraction pattern
to deduce how good/bad the optics are? Or just using the scope
to deliver images to the camera instead of the eye?

I don't understand about the 10X part. Is your friend using eyepiece
projection into the camera? If so, you get a better image and wider
fields of view with prime focus operation.

Google Christian Buil for a comparison of 10D, 20D and D70 cameras
and for insights into astro image postprocessing.

Mitch

 

[Les]

Archived from groups: rec.photo.digital (More info?)

MitchAlsup@aol.com wrote:
> Cannon 20D with a t-ring and a 2" focuser adapter
>
> I don't understant the "researching the optics of" part. Is your
> friend using the camera to take pictures of the diffraction pattern
> to deduce how good/bad the optics are? Or just using the scope
> to deliver images to the camera instead of the eye?
>
> I don't understand about the 10X part. Is your friend using eyepiece
> projection into the camera? If so, you get a better image and wider
> fields of view with prime focus operation.
>
> Google Christian Buil for a comparison of 10D, 20D and D70 cameras
> and for insights into astro image postprocessing.
>
> Mitch
>

He and another Physicist have a small humanities grant that is funding a
"What did it look like to them" investigation. They've already done
lots of optical bench work on the optics so this is a new field for them
and, as one might imagine, poorly funded. These instruments are so old
that only the curator is touching them!
So, are prime focus methods only recommended or could they get adequate
images with their present setup.
BTW the curator won't even let them remove, or have removed, the 300
years of dust, etc. on the lenses so are they just beating a dead horse?
Les

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

"egb" <eborys@martinauto.com> wrote in message
news:1111582461.427186.10580@o13g2000cwo.googlegroups.com...
>
> Canon 1Ds Mk II
>
>
>

Pentax K1000 & T-max 100. ;-)

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

Minolta SRT101 has a mirror lockup that's handy at the focal lengths of
telelscopes.

mike
"werdan" <footrotdog@that.gmail.fad.com> wrote in message
news:T%u0e.9760$C7.5731@news-server.bigpond.net.au...
>
> "egb" <eborys@martinauto.com> wrote in message
> news:1111582461.427186.10580@o13g2000cwo.googlegroups.com...
>>
>> Canon 1Ds Mk II
>>
>>
>>
>
> Pentax K1000 & T-max 100. ;-)
>

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

"mike regish" <mregish@comcast.net> wrote in message
news:566dnYyk4Ok8Md_fRVn-hA@comcast.com...
> Minolta SRT101 has a mirror lockup that's handy at the focal lengths of
> telelscopes.
>

And probably a tad cheaper than the Canon Godzilla

 

[Guest]

Archived from groups: rec.photo.digital (More info?)

"werdan" <footrotdog@that.gmail.fad.com> wrote:
> "egb" <eborys@martinauto.com> wrote:
> >
> > Canon 1Ds Mk II
>
> Pentax K1000 & T-max 100. ;-)

I'd take the Canon (well, if they'd come out with a version I can lift). I
just put a couple of rolls of TMAX 100 through my Mamiya 7, and despite the
MTF curves in the data sheets, it's no better than Provia 100F in terms of
pictorially significant detail rendition when scanned at 4000 dpi. And
looking at the film with a 60x microscope, I don't see much there that the
scan isn't getting.

So, as before, it looks to me that 35mm and 8MP digital are very similar
beasts. And 16.7 is a much bigger number than 8.

David J. Littleboy
Tokyo, Japan