From: Mark Gaffney <markgaffney@mac.com>

Date: June 28, 2008 7:07:18 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: Flea 2 colour cameras..


Thanks for the insight Tim, I`m yet to try auto-guiding which I hope to do initially with  a GPUSB device running through Astro IIDC & a Unibrain Fire-i webcam. Milton says I should be able to track stars down to magnitude 5 or 6. I plan to buy a small guidescope before the end of the year & use my IS 21A F04.AS camera to take photos. I did look at a Lumicon Easy Guider for my big scope, a C10-NGT but have decided to try a guide scope first. The interest in the Easy Guider was because of flexure worries. I`m still a bit unsure about the process, either with the guide star 180 degrees from the object of interest with the EG or in more direct line of sight with the guidescope. Polar alignment has been a problem for me too. I`m leaving the 10" out under a tarp at present hopefully P/aligned. I`ll have to check it by drift aligning when I have some sort of reticle(the one in Astro IIDC looks like the first candidate).  My firewire port is in need of repairs at present probably due to not using a repeater on my long cable.I`m finding with the C10-NGT it`s rather difficult discerning alignment stars from the rich field of view( they`re only slightly brighter than the other stars around Crux for instance?)& I`ve lost the 2 most obvious alignment stars behind trees this time of year.(Canopus & Sirius) Buying the Flea 2 is an "if" I manage to get a credit advance on my main credit card early next year?! I seem to be able to find new Astronomy items to buy without any trouble at all, you seem to be in a similar situation! Mark.

On 29/06/2008, at 10:08 AM, Tim wrote:


Mark:


I sometimes use the guiding chip with the SBIG, but it's a real pain

to find guide stars, unless you're shooting at a pretty short f/ratio.

Rotators help, I suppose, but they're out of my budget.  I have

TheSky6 on my HP laptop, and it displays the camera and guiding chip

field, which makes it easier to figure out which way to orient the

camera, but I seem to always rotate the wrong way searching!  Once I

find the guide star, though, it tracks well.  I find I have to start

with the densest filter I'm going to shoot with. It's no fun to take a

couple of exposures in Clear, and find the tracking fails with the

filter cutting the light.


I prefer a guide scope and one of the Fleas with Astro IIDC doing the

guiding.  Very fast getting going.  But flexure seems to pop up

everywhere!  I can't believe how many screws I've tightened chasing

down culprits.


I also bought the AO-7 with my ST2000, and it works very well except

that you can't use a focal reducer and reach focus with it on an SCT,

and the image scale is too big without one.


The SBIG camera works very well, but it's one of the heavier ones

available now.  I hate taking it in the field.  I used to have a

Starlight Xpress HX516, and the only gripe I had about it was that the

cables were very stiff, especially if it was cold.


I'm getting really lazy - I just put a second Robofocus on my Megrez 80!


Equinox 6 doesn't control the cameras anymore.  You need "Equinox

Image" for that.  But it works very well for that.


-Tim.


--- In Astro_IIDC@yahoogroups.com, Mark Gaffney <markgaffney@...> wrote:


Hi Tim, Milton`s already put me onto the Mogg website. I`ll have to

look into the focal reducer. Do you use the autoguide facility on your

SBIG camera at all & what do you use for processing with it? I priced

the ST 2000XCM some months ago (the colour version of yours) & it`s

well out of my price rang at $3825 Australian dollars. I understand

Equinox 6 can be used to control it? Mark.

On 29/06/2008, at 2:31 AM, Tim wrote:


Hi Mark:


Steve Mogg makes all kinds of adapters, and is in your neck of the

woods:  http://webcaddy.com.au/astro/adapter.htm


I have one of his c-mount/1 1/4" adapters that I use on one of my

fleas, plus the focal reducer that screws into the filter threads.


His adapters are made of a black plastic material - forget what it is.

They work fine for these small, lightweight cameras.  I also ordered

adapters for my Nikon lenses to mate up with my DSI, and these are too

easily deformed when you tighten them enough to keep things from

shifting under their own weight on the scope.  And you also have to be

wary of the threads stripping.


But again, the webcam and c-mount adapters are fine.


-Tim.


--- In Astro_IIDC@yahoogroups.com, Mark Gaffney <markgaffney@>

wrote:


Hi Tim, That`s interesting, I`ll have to decide myself what I want to

use the camera for (planetary or DSO) when I`m able to afford one.

I`ve ordered a Lumicon C-mount to 1.25 nosepiece at only $24.95 USD

from Telescopes.com, the postage turned out to be a bit of a problem

to Australia at $44.97 USD! I had a bit of a search & found 2 places

selling nosepieces without going too far into Google, the other was

in

England(haven`t heard back from them). I have Point Grey bookmarked &

I understand there`s a Sony 1/2" B/W or colour version of the Flea 2

at 1392x 1032 pixels (15fps) & a Sony 1/1.8" B/W or colour 1624x 1224

pixel job(15fps). They`re $995 USD & $1495 respectively plus $100 USD

each for the obligatory Development kit. Mark.

On 29/06/2008, at 12:35 AM, Tim wrote:


Hi Mark:


I have both the flea 640x480 color and the flea2 1032x776 color

camera.  Depending on what I'm most interested in, I might guide

with

one and image with the other.


I think where the smaller-pixel camera shines is on planetary

imaging,

because the ROI feature allows you to crop around the planet an

get to

high frame rates while still giving you the chip real estate to

aid in

centering the planet.  It also allows use of lower power barlows to

get the same pixel scales as cameras with larger chips.  And of

course, for planetary imaging, the pixel size is less important than

the image scale.


So, neither of my Fleas can quite replace the other.  Currently, I'm

fiddling with using the flea as a wide angle finder with an 11mm

c-mount lens on it, and the flea2 is on my C 9.25" with a meade f

6.3

FR for guiding, while my SBIG ST2000XM is on my Megrez 80 for

imaging.


I'm still fine tuning the polar alignment and have just eliminated

one

more source of flexure in the system, but following Milton's

suggestion for the Fleas, I have a 2" nebula filter in front of the

SBIG, and I'm imaging 13th magnitude galaxies from my home just 7

miles from downtown Los Angeles.  ;oD


I haven't been to the Pt Grey website in a while.  But I thought

they

added 1/2" ccd models to the Flea2 line?  Mine both have 1/3" chips.


-Tim.

--- In Astro_IIDC@yahoogroups.com, Milton Aupperle <milton@> wrote:


Hi Mark;


On 22-Jun-08, at 1:03 PM, Mark Gaffney wrote:



Hi Milton, I was wondering if you`ve had a chance to use the 1032x

776 version of the

colour Flea 2 camera.


Yes. I have a picture I took of M67 with it


http://www.outcastsoft.com/AstroImages/M67_20080307_MJA.jpg


I still prefer a CCD with larger pixels though.


I was thinking of the possibility of buying one of these early

next

year. I

notice the pixel value on the higher resolution model drops to

4.65x 4.65 micron pixels

compared to 7.4x 7.4 on the 640x 480 model.


You lose a 250% of the light gathering sensitivity with the pixel

size decrease too. So with 4.65 micron pixels you need 2.5 minute

exposure times to capture what a 1 minute exposure with a 7.4

micron

pixels can capture.


It`s an extra $100 USD for this model & Point

Grey also tack on $100 for a Development kit which has a IEEE 1394

b-a cable amongst

other things. I understand they`re transitioning away from the

Flea

camera now?


Yes the Flea2 use somewhat different electronics and are support

FireWire 800. Physically they are the same size.


I`m told PG

don`t sell nosepieces so I`m hoping one from Imaging Source will

do

the job.


It will. The noise piece uses a standard C or CS mount thread and

you

can get them all over the place. It's just a "C mount to M1.25"

adapter.


With the

Unibrain Fire-i camera in the meantime, I was thinking of buying

one of these nosepieces &

widening the opening to accomodate the C-mount thread (as Jim

Chung

did with a penknife I

understand).


The problem there is making sure it's perpendicular to the CCD and

that the lens mount here is an M10x0.5 or M12x0.5.


I`m thinking at the moment I`ll go with a $215 Orion Short Tube 80

Guide

scope to begin with & leave the Lumicon Easy Guider OAG til later

perhaps.


Just make sure your not putting too much weight on your mount. As I

said in another thread, you should try to keep the weight of

Optical

Tubes, cameras, weights, finders, cables to around 50 to 80% of the

mounts rated capacity. Go over that and it won't track well at all.


HTH..


Milton J. Aupperle





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