M31 with 70-200mm f4L (need help)

[Axeldude]

So I've taken some lights tonight and I'm having trouble processing the file, it's getting out all rough. 

It's my first time trying to process an image with this lens and it's quite a pain  

Could anyone rush me through on how to do this?

it's 50 minutes data @ 120 sec per exposures (f4.0) ISO 200

Here's the raw data files in dropbox (100mb)

Thanks for looking!

[Axeldude]

Btw: I've used no flats, bias or dark frames, tried to remove the most of the vignetting via Lightroom with the built in lens correction tool.

[Psychobilly]

Hi Axel..

it might be worth posting a "jpeg thumbnail" as well as a link to a 100MB download...

I did try using the 70-200/f4L for a while... but it's been replaced with a 200/f2.8L Prime these days...

Peter...

[Axeldude]

Link is in the OP

Will post jpeg when im home from work.

[Psychobilly]

Sorry what I meant is people can look at the jpeg before  deciding  if they want to go off an download a 100MB of raw data files...

Peter...

[lensman57]

So I've taken some lights tonight and I'm having trouble processing the file, it's getting out all rough. 

It's my first time trying to process an image with this lens and it's quite a pain

Could anyone rush me through on how to do this?

it's 50 minutes data @ 120 sec per exposures (f4.0) ISO 200

Here's the raw data files in dropbox (100mb)

Thanks for looking!

Hi Axel,

 I have done a quick process in StarTools and a bit on PS. You really need flats as the lens wide open is not illuminating the sensor either evenly nor uniformly. This is surprising the L lens is really designed for full format cameras so I did not expect such problems with an L lens and a crop format camera. The sensor has done well with regards to noise but you really need to do all the calibration frames, particularly Bias frames and Flats. I also attach a jpeg from Pixinsight ( ignor the red colour as this is typical of DSLR capture ) to show you the extent of  problem and there seems to be some canon banding artefacts too. I think that you need longer exposures and some about 45s for the core, you can combine them in PS .

Regards,

A.G