Astro Physics CCD67T reducer first test result

[Striker (Tony)]

Below are the test images I did with the LX200R and AP-CCD67T reducer.

approx reduction of .7x.

Their is field curveture and vignetting...I have applied Flats, darks and bias frames....the results are much better then the .5 reducer...will probably have to live with the field curveture until I can find a way to improve it.....no use talking to Meade as they dont even produce anything for their own scopes.

12 x 4 minute exposures ISO 800

[asimov (John)]

I can look past what little curvature & vignetting there is Tony.

Top job mate, I like 'em!!

[Astroman (Andrew Wall)]

It really is a shame Meade dont support a telescope line they have bought out, you would think they would have done something early. I wonder how it goes with the RCX400 line....

Great images none the less.

[gbeal]

Nice images Tony.
Can't help thinking though that I kinda liked the "Warp Factor 9" look of the
.5x. That and the relative price differences, and the notion that the .5x was most likely designed for a small CCD chip, and the AP was designed with the 6x7 film in mind................... What am I trying to say here?
Oh yes, nice shots.

[Striker (Tony)]

And thanks to Gary for letting me try his .5x reducer.

I am happy with the AP reducer...I could get rid of most of the field curveture with some cropping...just a bit more then I would ultimately like too.
12 months ago I would have been over the moon with this image....our expectations certainly do change.

[RB (Andrew)]

You blow me away Tony.

We certainly have come along way and the bar is certainly being lifted constantly.

Once you get this little prob sorted out you'll be in orbit.

[Striker (Tony)]

Thanks guys, but I dont think I will be able to sort the field curveture problem out unless Meade come up with Field flattner like all the other RC manufacturers do....the field flattner will have to be more dedicated to each piece manufacturer scope...I doubt a AP field flattner will work and besides that their $1500USD...lol

For now I will just live with curveture and crop most of it out.

[avandonk]

Hi Tony,
where is the FR in relation to your sensor in mm. with the current fr of 0.7. My guess is that if you move it towards the sensor the FR would drop to about 0.8 but the field curvature would be reduced. Is this move possible.
Also can you measure the focal length if not already known.

I think it is worthwhile pursuing this.

Bert

[Striker (Tony)]

Thanks Bert,

I can reduce the distance to F8 and yes the field curverture will be less...it's probably the option I will take.
I have the reducer approx 120mm from the sensor...I can reduce it to around 80mm.

[avandonk]

Worth a try. By the way the formula for focal reducers FR = (FL - x)/FL
where FL is the focal length of the focal reducer and x is the distance of the FR from the sensor all in mm. So on the figures you gave the FL of the CCD67T FR should be about 400mm. And for a FR of 0.8, 80mm distance between sensor and FR is about right.

Bert

[Striker (Tony)]

Thanks Bert...I didn't know the exact equation...thats simple..thanks....my measurement are only a visual estimate..I will accurately measure the distance.

Thanks

[Doug]

G'day Tony, The field curvature that you have illustrated could be fixed with about half an hours worth of post processing in Photoshop (most any version) if you are interested. It is not as though your images are beyond redemption. I am soon to submit a review of a tutorial DVD to Mike S. But let me just say at this time, that I have in my possesion a DVD of tutorials that are worth significantly more that the selling price, and one of the tuts addresses exactly what you are dealing with.
best,
Doug

[Striker (Tony)]

Ok Doug you have me interested....how do I find out..????

[h0ughy (David)]

stunning Tony, if you didnt tell me I wouldn't have noticed.