Comments on scope, please!

[perfrej]

Folks!

I have my new FLT98 on the mount now and have done some series of shots. I'm struggling to find the optimum setting for the Field Flattener 4, and I believe this shot was taken at setting 76 or possibly 73. Anyone with experience on that?

Conditions:

- 9 x 6 minutes at ISO 400

- No darks

- No flats

- Canon EOS 1000D (no filter at all)

- NEQ6

- Orion autoguider (starshoot kit)

- PHD Guiding through ASCOM/EQMOD

Main question: Is this scope OK?

Best regards and please do comment,

Per

[peter shah]

looks good to me at this size......but to give a more critical answer we would need to see afull frame full-res version....one thing that does strike me is you have lost colour in M51

[perfrej]

I'll get the color back

Maybe I should post a single, unprocessed, FIT so that you can look at it from the bottom and up...

[MjrTom]

The field looks pretty flat at this size image, a larger full frame image would allow for a better determination.

[perfrej]

OK, total re-process. Once again I find myself confused about de-bayer in PI. Images are backwards, which should make RGGB be GRBG, and that usually works. Don't know what I did wrong there... Anyway, full-field version, de-bayered in Nebulosity2 and processed in PI is available.

Since there are no darks involved (and no bias) there are some hot pixels (need to move onto dithering, I understand), but I hope you don't mind them

Please note and comment on saturated star shapes!

Sorry for size, but it needs to be like this (4.7MB)

[Beyond_Vision]

You would be better off using a shorter image that is less likely to be affected by tracking issue. The stars seem to have a small amount of trailing from top left to bottom right mixed with some possible distortion to the corners.

Regards

Kevin

[perfrej]

Kevin!

I may have a break in clouds later in the week according to the forecasts, and will take a few straight star-shots of a single star at single second exposures and situated in the middle and in the corners. Also, will do it with different settings on the flattener 4, with a flattener 3 that I have borrowed from a friend, and finally without flattener.

Images will be short enough to eliminate all guiding issues, and I will crop them to show the details without posting titanic stuff.

Thanks, everyone, so far!

/per

[perfrej]

OK, tried again, but this time M101. It turned out (discussed under equipment discussion "Mirror lockup") that I had mirror slapping on the Canon, therefore the elongated bright stars.

I have since built a remote shutter device and enabled mirror lockup, and Nebulosity now uses 3000 ms of mirror lockup delay in order to let the vibrations die out.

The following image is 6x10min at ISO 400 under not so dark conditions (no blackness in the skies until August here), quick and dirty processed in PI, no darks, no flats, no bias.

I do believe the stars are round! Also, I'm about to clear the scope and accept delivery. What do you think?

Thanks again, everyone, for the time and dedication on this forum!

/per

Full res JPG is HERE.