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SF 6 Ai Negafix and HDR output

PostPosted: Fri Apr 25, 2003 12:51 pm
by GButch
I have begun batch scanning negatives using SF 6 Ai for later processing in SF 6 HDR.

What are the appropriate settings in the Ai Negafix dialog? I certainly do not want "Auto" and I always make sure that the negafix histograms have been reset so that the limits on all three channels are set to full range, 0 and 255.

But what about the emulsion profiles. Are they relevant? Should I just leave it where it was last set? Should I select "Other" as the film type? I will be presented with the same negafix dialog again when I open the file in HDR.

Thanks for any guidance.

George Butch
Plantation, FL

PostPosted: Fri Apr 25, 2003 9:56 pm
by ilyons
George,

If you are going to use HDR the your best option in Ai is to set the "Scan Type" to 48 Bit HDR Colour. The scanner will then batch scan your images with NO correction. The images will still be reversed and the mask still present. You use HDR with NegaFix to carry out your edits, colour corrections etc.

Ian

PostPosted: Fri Apr 25, 2003 11:03 pm
by GButch
Ian,

Thank you for the reply. Your tutorials have taught me a lot over the past couple of years.

I already do as you suggest by specifying 48 bit HDR color as the scan type. My concern is that even in this mode, the SF 6 Ai Negafix dialog is still present and affects the preview. I'm really asking if the settings in the Negafix dialog in any way affect the "raw" scan that will be saved and later opened in HDR.

George...

PostPosted: Fri Apr 25, 2003 11:37 pm
by ilyons
George,

Once you select 48 Bit HDR Colour you'll find that NegaFix, Color Managment and all other features (gamma-gradation being an exception that you can override) don't impact on the final scan.

I think the problem you and other users have is that Negafix is still present and "apparently" functional when 48 Bit HDR Colour is selected, yet all the others tools are disabled. This may have been an oversight or a situation where disabling it would have been too difficult for LaserSoft to implement. Hopefully someone form LaserSoft will look into this shortly as it is a query that I can recall answering probably 3 times in as many weeks. I would like to see a situation where the NegaFix dialog does NOT appear when the user chooses 48 Bit HDR Colour as the Scan Type.

Ian

PostPosted: Sat Apr 26, 2003 12:30 am
by GButch
Ian,

Thank you. Your answer was just what I expected, but I wanted to be sure.

George...

PostPosted: Sat Apr 26, 2003 5:17 am
by Gregory C
on the other hand, Negafix allows us to see a good representation of the photograph in the Preview window, and therefore allows us to make good judgements above how and where to select which part of the image to scan. film offset adjustments may also be needed. without Negafix, most of the image would be too dark or too mirky to make these judgements.

SF HDR does not allow batch scanning of folders of images so placing a frame just once and scanning a whole batch of images is not possible. the Job Manager within SF HDR does not allow pre-defining of frames during import of images into the queue so once again, it is not possible to apply a frame to all images in a 'batch'.

therefore, it is very important that frames be applicable when batch scanning negatives using SF Ai. without Negafix, this might be quite difficult to do effectively and accurately.

PostPosted: Sat Apr 26, 2003 8:45 am
by ilyons
Gregory C wrote:on the other hand, Negafix allows us to see a good representation of the photograph in the Preview window, and therefore allows us to make good judgements above how and where to select which part of the image to scan. film offset adjustments may also be needed. without Negafix, most of the image would be too dark or too mirky to make these judgements.

SF HDR does not allow batch scanning of folders of images so placing a frame just once and scanning a whole batch of images is not possible. the Job Manager within SF HDR does not allow pre-defining of frames during import of images into the queue so once again, it is not possible to apply a frame to all images in a 'batch'.

therefore, it is very important that frames be applicable when batch scanning negatives using SF Ai. without Negafix, this might be quite difficult to do effectively and accurately.


Gregory,

I think you misunderstood the question. George is trying to batch scan in Ai - he can only set the frame crop once. This doesn't need NegaFix, if anything NegaFix being active makes it more difficult. The following screenshot shows how SilverFast preview SHOULD look like if LaserSoft disabled ALL image processing tools when 48 Bit HDR colour was selected. After all this is what the user actually gets.

Image

Batch scanning in Ai only allows you one prescan/crop per batch of X image so I'm not sure what you think we'd be loosing.

48Bit HDR colour mode has a purpose - scan an image for subsequent processing in SilverFast HDR! As soon as you load the HDR image into SilverFast HDR and set it to Negative the image will reverse and NegaFix will appear. Batch processing in HDR was not the question and what we do in Ai should NOT at any time dicate the FINAL result - we want a full frame - full range CAPTURE - leave the processing etc until the image is opened in HDR.

PostPosted: Sat Apr 26, 2003 2:27 pm
by Gregory C
with Ai, I usually set up the crop/frame to get the largest scan area possible *without* including the film border. I can do this once and scan the whole roll or strip of film pretty efficiently although I sometimes need to go back and adjust the offset of some frames and rescan them.

I note that in your screen shot, you too did not include the film border in your frame ;-)

with HDR, the only 'batch' mode available is via Job Manager. Job Manager's default frame is the whole of the HDR image. adjustments to the frames in Job Manager must be done manually, one image at a time. by carefully setting the frame in Ai, I can avoid the monotonous task of setting the frame in Job Manager.


I also scan in HDR color. to set the frame correctly, I need to see the film border in the preview window. I guess it depends on the photograph whether the border is easier seen with the photograph inverted or otherwise. in some cases, turning Negafix off would certainly make the border more easily distinguishable.

A note though. Since HDR simply saves the scan data into an HDR file, I surmise that the saved file will be the same whether you choose Negafix or Positive. If that is the case, then each user can choose the setting according to personal preference or characteristics of the film although I would not advise changing the Positive/Negafix setting in the middle of setup because doing so would reset all of your frame settings.

regards
Gregory