Best way to scan underexposed slides?

[peakoverload]

I'm in the process of scanning thousands of old family photos all shot on Kodachrome Transparency. Some of the older slides were shot on a very basic point and click camera and are very underexposed. I'm using Silverfast SE Plus 8.8.0r5 and have using a mixture of AutoCCR, Histogram, Gradiation tools as well as Multi Exposure but the results I'm getting are still very dark with loads of noise in the shadows. If I boost the exposure too much than all that happens is I get more noise and an almost posterisation effect in the colours.

Is there anything I can do to get better results? I have Photoshop CC and Lightroom at my disposal which I do use to further edit my scans anyway but is there anything I can do at the scanning stage to capture more detail?

Are the HDR and HDRi options in Silverfast something that can be read/processed by Photoshop or is that purely for Silverfast HDR?

[LSI_Ketelhohn]

Dear customer,

It is difficult to say anything without seeing the images. Consider contacting us through the "Request online support" in the SilverFast Help menu.

Have you activated Multi-Exposure? It reduces the noise in the dark areas.

Please be aware that underexposed images are likely to have a very low dynamic range to start with. Brightening them will not always result in an optimal image. You can try to vary the black point to reduce noise effects in the shadow. However as these result from the scanner sensor itself they can not be prevented completely.

HDR(i) RAW images can be opened in third party software. But you have to remember to deactivate automatic colorspace replacement and will need to adjust the gamma which is a linear gamma of 1.0 in these images.

Kind regards,
Arne