Image size for stacking.

[Ronclarke]

Last night I took 40+ images with the Canon 1100d, there size (according to DSS) was 4290 x 2856.

Just took some Flats with the same camera and there size (according to DSS) is 3906 x 2602.

DSS won't stack them because of the different sizes. What is the reason for the difference in image size and

What can I do about it?

 

Cheers

Ron

[vlaiv]

Only reason that I can think of, except of course DSS having trouble reading those particular files, would be change of image size in camera settings?

Did by any chance anyone use that camera during daytime? Maybe they set different image size / returned to jpeg capture or similar and you did not notice that?

[Ronclarke]

APT told me to use the Av setting instead of the M setting, that's the only change I'm aware of??

 

Ron

[vlaiv]

Just now, Ronclarke said:

APT told me to use the Av setting instead of the M setting, that's the only change I'm aware of??

 

Ron

Not familiar with APT but I suspect that is because of the need for "automatic" flat exposure - it is Aperture priority mode, meaning that aperture does not change (nor it could since you have your camera on the scope instead of lens) so camera automatically determines needed exposure time. It should not affect the file/image size.

[Ronclarke]

That's what I thought! The mystery deepens!

Thanks

Ron

[vlaiv]

3 minutes ago, Ronclarke said:

That's what I thought! The mystery deepens!

Thanks

Ron

What do files look like? Do they have cr2 extension? What is the size of them? Can you open them in another application and check stats - like image size and such?

Canon has some free utility for image enhancement - maybe use it to see what the images look like?

[Ronclarke]

They are all cr2, I'll check on some different software tonight, thanks

Ron

[michael8554]

There's no way of telling if the flats are cropped or just a different output size. 

Put the flats into Photoshop, Paintshop Pro, etc, and resize to the sub's size. 

They won't Save as cr2's, I'm not sure if DSS will mix formats. 

Michael 

[vlaiv]

3 minutes ago, michael8554 said:

There's no way of telling if the flats are cropped or just a different output size. 

Put the flats into Photoshop, Paintshop Pro, etc, and resize to the sub's size. 

They won't Save as cr2's, I'm not sure if DSS will mix formats. 

Michael 

This is very good suggestion, as there are two possible cases:

- crop

- scale

In principle you should be able to tell by stretching hard one of lights comparing to master flat. If you happen to have dust shadows that will help quite a bit as you will be able to tell their respective position and if cropping or scaling helps.

 

[alan potts]

I don't understand what is happening here, as I use a 40D with a couple of scopes at the moment and APT and all Flats Darks (if used) and Dark Flats etc are the same size.

Alan

[Demonperformer]

That is seriously weird, as, according to this site, 3906 x 2602 isn't even a valid option for image size ...

[wxsatuser]

On 07/08/2019 at 16:06, Ronclarke said:

Last night I took 40+ images with the Canon 1100d, there size (according to DSS) was 4290 x 2856.

Just took some Flats with the same camera and there size (according to DSS) is 3906 x 2602.

DSS won't stack them because of the different sizes. What is the reason for the difference in image size and

What can I do about it?

 

Cheers

Ron

Are you using latest DSS?

[Ronclarke]

No, 4.1.1 will the update be worth it?

Edited August 10, 2019 by Ronclarke
added text

[Cornelius Varley]

On 07/08/2019 at 16:30, Ronclarke said:

They are all cr2, I'll check on some different software tonight, thanks

Ron

What image resolution does windows explorer give under properties.

[wxsatuser]

52 minutes ago, Ronclarke said:

No, 4.1.1 will the update be worth it?

Should be ok.

[Ronclarke]

5 hours ago, Cornelius Varley said:

What image resolution does windows explorer give under properties.

Same as DSS..?

[wxsatuser]

3906 x 2602 according to DXOmark is the resolution of a Canon 1000D, strange!