Stack function not working with tiff files

[Phil Davidson]

I've been trying to use the stack function to create star trails from around 60 tiff files created by ACDsee Photo Studio 6. The files preview fine in the stack file picker but the final stack has virtually no data in it (see attached file Bad stack.tiff). I've also attached one of the original tiff files DSC04769.tiff. I've tried with jpgs of the same images and it works fine. Having read a couple of older posts here I also tried removing the metadata and also using smaller files. I even tried creating new ones using a batch in Photo itself but all with the same result.

[Chris B]

Hey Phil Davidson,

Would you mind uploading the tiff files into this private Dropbox folder so that I can have a go? I have a feeling I've seen this before but ideally I'd need to attempt the stack myself.

It might be worth also trying to turn off auto-alignment.

I would probably recommend using an exposure time of 1m 30s as opposed to 31s. Our Photo Export, James does these kind of shots alot and I recall him saying 1m 30s is generally the perfect amount of time but I am no expert and you will both know a lot more than I do in this subject. 

[Phil Davidson]

Hi Chris,

 

Sorry for the slow reply. I've just uploaded five of the tiff files to that folder. I was working with about about 60 originally but I've just tried again and those five produce the same bad result when creating a new stack. Auto-alignment is off otherwise Photo does a wonderful job of putting all the stars on top of one another and removing all the trails 🙂 It also produces the same result with those tiff files. It seems to be something in the encoding. I've also just tried a stack from the RAW files and that works fine. I'm not entirely sure my laptop could handle stacking 60 of them though!

Thanks

 

Phil

[Chris B]

Hey Phil,

There might be an issue with the bit depth. If you convert the stacked document to 8 bit it looks alright. Or you can batch convert them using Photo to 8 bit and that also works. 

I think I'll still ask a developer to look into it. 

It could be the TIFF encoding, so have you tried converting not using ACDSee?

[Phil Davidson]

Hi Chris,

 

Ok, didn't think of trying that one. I'll give it a go.

As far as encoding goes, I did try getting Photo to batch convert the files to tiff just in case it was ACDSee doing something odd but with the same result.

Thanks for your help with it.

 

Phil