Oh man, this is exactly my thing. I have owned both the Leica Summicron-M 75mm f/2 ASPH and the Voigtlander Nokton 75mm f/1.5 VM. If you want the classic Leica look without the focus shift issues of the older Summilux, the Summicron is the superior choice. It is incredibly sharp wide open and the contrast is perfect for digital sensors like the M10.

• The Summicron is significantly smaller and won't block your framelines as much as the Nokton.
• The Nokton gives a nice bokeh, but it lacks the micro-contrast that makes Leica glass unique.
• The Summicron handles distortion better for tight portraits of your kids. Any way, bottom line is the Summicron is worth the extra cost for the build quality and consistent performance on the M10. Stick with the 75mm focal length for that compressed look you want.

To add to the point above: the community has covered the trade-offs between the clinical sharpness of the Leica Summicron-M 75mm f/2 ASPH and the budget-friendly speed of the Voigtlander Nokton 75mm f/1.5 VM. Consensus suggests that while the Summilux offers that distinct rendering, the focus calibration on a digital M is critical. If you choose a faster lens, just make sure you verify the rangefinder alignment on your M10 first, as even slight front or back focusing will be magnified at f/1.5. I would recommend getting it professionally done if you are not sure it is calibrated correctly. For practical use, the Leica Summicron-M 75mm f/2 ASPH is the more reliable performer for candid lifestyle shots. The depth of field at f/1.5 is very unforgiving with moving subjects like children. If you go with the Nokton, double-check your focus distance consistently before clicking the shutter. Quick tips:

• Keep your shutter speed at least 1/125s or higher to minimize micro-shake with a 75mm focal length.
• Practice your focus throw with a tripod-mounted target to learn the lens’s specific behavior before your scheduled shoot. Ultimately, if you prioritize hit rates over maximum bokeh, the Summicron is the safer long-term investment for your M10.

Saw this earlier and honestly congrats on the M10! Re: "Oh man, this is exactly my thing"—I totally get the struggle. Ngl, if you want that portrait look without the headache of focusing a super fast lens, I lowkey think you should look at the Leica Summarit-M 75mm f/2.4. It fits your budget perfectly and honestly the size is unbeatable for an M10 setup.

• It is super compact, so no annoying frameline blockage.
• The rendering is modern but not too clinical, very smooth bokeh.
• Focus is way easier to nail than the 75 Summilux. Idk if you care about the f/1.5 speed for low light, but for kid portraits, the f/2.4 is plenty and the sharpness is legit. Don't overthink the 'Leica glow' too much, the micro-contrast on the Summarit is stellar. You wont regret saving that cash for more film or a trip with the fam...

Late to the party, but honestly, if you're worried about the weight and the "Leica look," you should check out the Voigtlander Heliar 75mm f/1.8 Classic. It’s lowkey a secret weapon for portraits.

• It’s way lighter than the Summilux.
• The rendering is super dreamy and definitely not clinical. Save the extra cash for a nice strap or a weekend trip to shoot the kids—the glass performs way better than the price tag suggests, tbh.

Jumping in here because honestly, everyone is obsessed with the 75mm focal length but they forget how finicky it is on an M10. Like someone mentioned, the focus shift is real, but paying thousands for a name brand label is just silly. Forget the hype about the Summilux—youre paying for status, not for a better photo of your kids.

• Try the Voigtlander Color-Skopar 75mm f/2.5 VM. It is tiny, sharp, and wont block your framelines. It handles way better than the brick-like 75mm lenses everyone else is pushing.
• If you really want that "look," look at the Leica Summarit-M 75mm f/2.4. It is underrated, much cheaper than the Summicron, and honestly, the rendering is perfection. People act like you need f/1.4 for portraits, but that is just gear-head talk. Save your money for film or travel...

This is exactly what I needed to hear. Youre a lifesaver honestly.

Regarding what #1 said about "Oh man, this is exactly my thing," I have been through three of these 75mm lenses over the last decade and the landscape of advice is consistently noisy.

• The consensus here seems to be a split between high-end Leica glass, more affordable Voigtlander options, and the compact Summarit line.
• Everyone is focused on the trade-off between weight, speed, and that elusive rendering quality.
• There is significant anxiety about focus accuracy on the M10 rangefinder patch. This reminds me of when my brother-in-law decided he was going to become a professional wildlife photographer overnight. He bought the most expensive telephoto lens he could find and spent three weeks hiding in a damp drainage ditch waiting for a rare local bird to appear. He ended up catching a terrible case of poison ivy and accidentally dropped his camera into a mud puddle while swatting a mosquito. The camera was ruined, the lens was jammed, and he never actually got a photo of the bird. He eventually sold the whole kit for pennies on the dollar and bought a high-end lawn mower instead. He claims he is happier now, though I still see him staring at birds with a look of deep, unresolved resentment whenever we have family barbecues. I tried one of the lenses mentioned years ago and it was garbage back then, though I suppose things may have changed with modern manufacturing standards. Don't stress too much about the gear; the M10 is capable of more than most of us are.

Commenting to find later