Why no mirror telephotos for DSLR Canon?

Started Jan 25, 2010 | Discussions
Lee Jay Forum Pro • Posts: 52,740
Re: Question about telescope

gdjoslin wrote:

Can I put a T mount on this scope to take pictures are not.
It is a NexStar 114 GT Computerized Telescope.

I sort of doubt you can get an SLR mounted to that without modifications. I had a Nexstar 130SLT for a while, and it couldn't do it without a barlow or without moving the main mirror forward. The problem is that these little Newtonians don't have enough back focus for an SLR at prime focus to reach focus (you can't move the camera "in" far enough.

-- hide signature --

Lee Jay
(see profile for equipment)

 Lee Jay's gear list:Lee Jay's gear list
Canon IXUS 310 HS Canon PowerShot SX50 HS Canon EOS 7D Mark II Canon EF 70-200mm f/2.8L IS II USM Canon EF 8-15mm f/4L Fisheye USM +23 more
neilgc Contributing Member • Posts: 970
Re: 4 reasons

The first of these is the most important. I have a makinon 400mm that I originally bought for my Yashica 35mm slr. I recently bought an adapter to use it on my 40D. The contrast is so low that it is hard to focus. Also, focus is very senstive, you really need to get it right.

Now if someone made a top quality one with autofocus, it would be wonderful beacuse they are short and light. As it stands, they are just for the odd special effect picture or soft portraits.

Franz Kerschbaum Regular Member • Posts: 321
Re: 4 reasons

I am quite happy with my NexStar 5SE as a very good mirror lens!

 Franz Kerschbaum's gear list:Franz Kerschbaum's gear list
Canon EOS 5D Mark II Canon EOS 5D Mark III Canon EOS 7D Mark II Canon EOS M6 Sigma 14mm F1.8 Art +1 more
neilgc Contributing Member • Posts: 970
Re: 4 reasons

lovely shot, but I guess you can't wander around snapping with itcan you? It looks more like a telescope than a lens. Or am I wrong?
What does it cost by the way?

Franz Kerschbaum Regular Member • Posts: 321
Re: 4 reasons

Not that expansive, the whole system including computerized mount is only $700 and is in total about 14 kg. If you remove the telescope from the mount it weights about 8kg. There is also the smaller (4") Nextstar 4 SE with 5 kg. If you compare thiese values to lenses of comaprable dimensions thats not so bad. You can mount any DSLR with a T2 adapter.

Franz

 Franz Kerschbaum's gear list:Franz Kerschbaum's gear list
Canon EOS 5D Mark II Canon EOS 5D Mark III Canon EOS 7D Mark II Canon EOS M6 Sigma 14mm F1.8 Art +1 more
Franz Kerschbaum Regular Member • Posts: 321
Re: 4 reasons

SORRY I mixed up two photos (its long ago 2006!). My original post of the eclipse was using a Yashica 500mm F:8 mirror!!!

This is the Celestron Nexstar frame:

Sorry for the confusion!

Franz

 Franz Kerschbaum's gear list:Franz Kerschbaum's gear list
Canon EOS 5D Mark II Canon EOS 5D Mark III Canon EOS 7D Mark II Canon EOS M6 Sigma 14mm F1.8 Art +1 more
neilgc Contributing Member • Posts: 970
Re: 4 reasons

My old Makinon weighs about 400g; pity it doesn't take good pictures

gdjoslin
gdjoslin Senior Member • Posts: 1,050
Thanks I will check it out n/t
samWebster123 Senior Member • Posts: 1,153
Forget the mirrors!

IQ is generally crap apart from the Minolta mirror lens which I once had. Even that lens is substandard compared to something like a tokina 4005.6 apo which is cheaper and easier to carry around.

I even had a sigma 600mm mirror once and it was a complete waste of money compared to buying a tokina or sigma apo 400 for the same price.

IMO you're better saving your money up for a canon 400mmf5.6 or 300mmf4 with a tc.

 samWebster123's gear list:samWebster123's gear list
Canon EOS 5D Mark II Canon EOS-1D Mark IV Canon EOS-1D X Canon EF 300mm f/2.8L IS USM Canon EF 600mm f/4.0L IS USM +4 more
Lee Jay Forum Pro • Posts: 52,740
Re: Forget the mirrors!

samWebster123 wrote:

IMO you're better saving your money up for a canon 400mmf5.6 or 300mmf4 with a tc.

What if you want, say, 4500mm (this is a crop - 90,000mm-equivalent)?

-- hide signature --

Lee Jay
(see profile for equipment)

 Lee Jay's gear list:Lee Jay's gear list
Canon IXUS 310 HS Canon PowerShot SX50 HS Canon EOS 7D Mark II Canon EF 70-200mm f/2.8L IS II USM Canon EF 8-15mm f/4L Fisheye USM +23 more
Eyegasms Regular Member • Posts: 126
Re: Forget the mirrors!
gdjoslin
gdjoslin Senior Member • Posts: 1,050
Re: Forget the mirrors!

That is a great shot. What scope are you using?
--
Gary

http://joslin-family-photos.smugmug.com/

gdjoslin
gdjoslin Senior Member • Posts: 1,050
Opteka has an 800mm,
Lee Jay Forum Pro • Posts: 52,740
Re: Forget the mirrors!

gdjoslin wrote:

That is a great shot. What scope are you using?

Thanks. Just a little Meade ETX-125 (5" Mak).

-- hide signature --

Lee Jay
(see profile for equipment)

 Lee Jay's gear list:Lee Jay's gear list
Canon IXUS 310 HS Canon PowerShot SX50 HS Canon EOS 7D Mark II Canon EF 70-200mm f/2.8L IS II USM Canon EF 8-15mm f/4L Fisheye USM +23 more
neilgc Contributing Member • Posts: 970
Re: Opteka has an 800mm,

Indeed, they make some other focal lengths too. Till I see someone post some good pictures of something where you can judge sharpness and contrast, I'll remain unconvinced.
Neil

gdjoslin
gdjoslin Senior Member • Posts: 1,050
Re: Opteka has an 800mm,

I am not saying they are good or bad, wish they were good. I am getting ready to get a 50-500 or 150-500, they cost a lot more
Here is a link to a good one.
http://www.flickr.com/photos/sudheeras/4021721122/
--
Gary

http://joslin-family-photos.smugmug.com/

jpr2 Forum Pro • Posts: 15,412
re: judging by the output the Minolta AF-Mirror is quite good an option

ScottyNV wrote:

but they are the only ones to currently have a mirror-tele in their lineup.

I have and use the Sigma 600/8 mirror on my 5D2. IQ is quite good, if not as spectacular as that of the 600/4L... but at 10% the retail price, it certainly has a place in my bag. When hiking for a week, off the beaten path, which would you rather carry? 600/4L at 12#, 2' long or the mirror at 1.5#, 6" long... I know which one I prefer!

I'd not mind to have such AF-capable CAT in my canon bag at all,
it seems that ability to autofocus can make all the difference !!!,
many excellent shots there:
http://www.flickriver.com/groups/500mmf8reflex/pool/interesting/

and even bokeh is quite passable:

jpr2
--
~
street candids (non-interactive):
http://www.flickriver.com/photos/qmusaget/sets/72157609618638319/
music and dance:
http://www.flickriver.com/photos/qmusaget/sets/72157600341265280/
B&W:
http://www.flickriver.com/photos/qmusaget/sets/72157623306407882/
wildlife & macro:
http://www.flickriver.com/photos/qmusaget/sets/72157600341377106/
interactive street:
http://www.flickriver.com/photos/qmusaget/sets/72157623181919323/

Comments and critique are always welcome!
~

Bill MacBeth Senior Member • Posts: 1,631
Re: I have a $700 1900mm f15

ljfinger wrote:

Bill MacBeth wrote:

I sill have the telescope and need to know -- can a 5DM2 operate without a lens, to use eyepiece projection?

Yes, but eyepiece projection (a.k.a afocal) requires a lens on the camera. Otherwise, it's called "prime focus".

Lee Jay,
I guess your answer is yes, a 5DM2 will operate without a lens attached.

Here's what I mean by 'eyepiece projection'. I've used the technique many times on my on reflector, and on a larger refractor at a university. An eyepiece (normally used for visual observation) is moved away from the visual focal location, so that it profects a focused image about four inches outside itself. The film plane or sensor plane of the camera is placed at that location. No lens is used on the camera.

Prime focus (no eyepiece) projects an image too small for lunar and planetary photography, which is my intended use.

Regards, Bill

RobertSigmund
RobertSigmund Forum Pro • Posts: 10,750
Re: Forget the mirrors!

Wonderful pictures and a proof that mirror lenses can be very good iq-wise. The donut blur is just a matter of taste. Thanks

 RobertSigmund's gear list:RobertSigmund's gear list
Panasonic Lumix DMC-LF1 Canon EOS 5D Canon EOS 20D Sony SLT-A55 Sony SLT-A77 +2 more
RobertSigmund
RobertSigmund Forum Pro • Posts: 10,750
re: judging by the output the Minolta AF-Mirror is quite good an option

Wow - time to get one and either reactivate my minolta film slrs or buy a sony dslr.

 RobertSigmund's gear list:RobertSigmund's gear list
Panasonic Lumix DMC-LF1 Canon EOS 5D Canon EOS 20D Sony SLT-A55 Sony SLT-A77 +2 more
Keyboard shortcuts:
FForum MMy threads