Switching Spot Size

Hi,

I have a question regarding switching from a 15mm to a 12mm spot size. I know that when you switch to a smaller spot size, you need to increase the joules in order for it to stay effective.

If you used 20 joules and a 5ms pulse width with the 15mm spot size, how do you know, approximately, what the equivalent settings are for the 12mm?

Thank you :slight_smile:

The question is why do you want to switch spot size ??? I would stick with 15 mm at the highest possible setting ( 25 Joules or
30 Joules depending on laser used ) and then go down to 12 mm spot size. With 12 mm I would probably go to 24 or 26 Joules.

The technician told me that after that setting, in order to increase the joules the spot size should be switched to 12mm. I know that it can go up to 25 joules on this machine (for the 15mm), but is it because they won’t go higher than those settings for the 15mm because of my skin type (type III; light-skinned middle eastern)?

There is something wrong in what you are being told. If they can not raise the energy with 15 mm because of your skin type, then why would they feel comfortable in raising it with a 12 mm spot size ?? After all, it is still being applied on your epidermis. 12 mm penetrates less deep, yet it would still create issues at higher fluences. What area are you getting treated ???

Thanks for replying :slight_smile:

This will be for my lower back and thighs. I have been treated at 20 joules, 5 ms, 15 mm, no problem (slight redness in the areas that went away after a few hours and the pain wasn’t that bad). I think I can go up one degree (in terms of stronger settings). So I figured I should be able to go up to ~22 joules for my next treatments (since I’ve done several already). I will ask the technician to do a test patch with those settings so that we make sure it’s okay.