TG-6 & Backscatter M52 Wide Angle Lens issue

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BoltSnap

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@BackscatterUW

Backscatter has an account here on SB: BackscatterUW

Perhaps you should send them a PM with a link for this thread.
 

coralcruiser

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Interesting that you’re having such a difficult time with assistance from backscatter. I’ve never had a problem getting help from them but I usually give the CA store a call and speak with them direct. I’ll be using the lens for the first time in two weeks and my friend just used it a few weeks ago in St Croix with no issues. She used the underwater macro setting on all dives, even when shooting video and had great results.
 
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hedonist222

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a little fiasco from michael saying "zoom out of the vignetting"

when others commented that they didn't have any vignetting, he back tracked from that statement and then someone else from backscatter got in contact with me

unfortunately their only suggestion was to restore the camera to factory settings

I intend to do that in a few days

lets see what happens
 
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I have been following this and believe the issue may come down to picture format, RAW vs. JPG. I run a TG-6 with a PT-059 housing and usually record in both RAW and JPG. I noticed a while back that the RAW files had vignetting while the JPGs did not. (The latter lends truth to Backscatter's no vignetting claim.) For comparison, the following are the same picture in RAW and JPG.

. P3270016.ORF.jpg Outbound.jpg

When I recently added the Backscatter M52 Wide Angle wet lens, the issue became more pronounced with RAW files. In the following the hood is visible. (To confirm, the lens was burped and fully screwed on.)

P6180019.ORF.jpg

My reading on this topic suggests that this is a common issue across brands (Olympus, Canon, etc.). Also, the camera monitor does not show the vignetting. So as I recently discovered, one may not even be aware of the problem until at home after the dive.

So two solutions I have identified are 1) to shoot in both RAW and JPG; and/or 2) zoom in slightly to get past the vignetting. I guess cropping in a post is a third solution but I really try to frame my pictures underwater and am not smart or skilled enough to imagine trimming the edges off as I am setting up the shot.

There may well be other, better, solutions as well. I leave for Maui in a week and even though I strongly prefer to work with RAW files I will shoot in both RAW and JPG.

Please do not hesitate to let us know if you find a better solution. Best of luck!
 
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hedonist222

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I have been following this and believe the issue may come down to picture format, RAW vs. JPG. I run a TG-6 with a PT-059 housing and usually record in both RAW and JPG. I noticed a while back that the RAW files had vignetting while the JPGs did not. (The latter lends truth to Backscatter's no vignetting claim.) For comparison, the following are the same picture in RAW and JPG.

. View attachment 667564 View attachment 667565

When I recently added the Backscatter M52 Wide Angle wet lens, the issue became more pronounced with RAW files. In the following the hood is visible. (To confirm, the lens was burped and fully screwed on.)

View attachment 667566

My reading on this topic suggests that this is a common issue across brands (Olympus, Canon, etc.). Also, the camera monitor does not show the vignetting. So as I recently discovered, one may not even be aware of the problem until at home after the dive.

So two solutions I have identified are 1) to shoot in both RAW and JPG; and/or 2) zoom in slightly to get past the vignetting. I guess cropping in a post is a third solution but I really try to frame my pictures underwater and am not smart or skilled enough to imagine trimming the edges off as I am setting up the shot.

There may well be other, better, solutions as well. I leave for Maui in a week and even though I strongly prefer to work with RAW files I will shoot in both RAW and JPG.

Please do not hesitate to let us know if you find a better solution. Best of luck!


Very interesting.

I will share this thread with backscatter and try it myself.

The thing is - during their customer support, they said they could not replicate my issue.
Were they shooting in JPG?
 

Barmaglot

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I noticed a while back that the RAW files had vignetting while the JPGs did not.

This is generally indicative of your RAW converter not applying the correct lens profile to the photo. Modern lens designs frequently accept various optical imperfections in order to reduce overall lens dimensions, and TG-6 is especially constrained there, as it has to fit a 4x zoom lens into a fairly thin camera body without having it extend outwards, as most compact zoom lenses do. The camera's internal software automatically corrects those, hence the good JPEG output, but your RAW converter appears to be outputting the raw optical result, with all the aberrations.
 
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This is generally indicative of your RAW converter not applying the correct lens profile to the photo. Modern lens designs frequently accept various optical imperfections in order to reduce overall lens dimensions, and TG-6 is especially constrained there, as it has to fit a 4x zoom lens into a fairly thin camera body without having it extend outwards, as most compact zoom lenses do. The camera's internal software automatically corrects those, hence the good JPEG output, but your RAW converter appears to be outputting the raw optical result, with all the aberrations.
Thanks for the explanation! I could not figure out why the exact same picture from the exact same camera was producing two different variations.
 

BoltSnap

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This is generally indicative of your RAW converter not applying the correct lens profile to the photo. Modern lens designs frequently accept various optical imperfections in order to reduce overall lens dimensions, and TG-6 is especially constrained there, as it has to fit a 4x zoom lens into a fairly thin camera body without having it extend outwards, as most compact zoom lenses do. The camera's internal software automatically corrects those, hence the good JPEG output, but your RAW converter appears to be outputting the raw optical result, with all the aberrations.

So what is the fix?
 

Barmaglot

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So what is the fix?

It's possible that the RAW converter in question already has the proper lens profile built-in and the option to apply it is simply disabled for some reason. If it doesn't, then it needs to be added, either by upgrading to a newer version, or importing a lens profile definition. Adobe Camera Raw, for example, supports TG-6 starting from version 11.3, and I recall that it's possible to download its lens profiles separately and import them into other packages such as RawTherapee.
 
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