billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

Do you like the images you get now?, they will not improve any with the D780. My suggestion is to shoot the D610 until it dies, who knows, you may pass on before the D610.

camerapapi Loc: Miami, Fl.

User ID wrote: "You wont see a difference."

I agree. If your images are not good now a new camera will not change that. You have to ask yourself if the D610 is not doing what you need from it. It has excellent resolution with 24 Mp., a decent control of noise and its AF good enough for a majority of applications.
Now, you said you have OK lenses, not that I know what is exactly an OK lens. Modern lenses are of excellent quality and I have several old ones that have outstanding resolution. Have you reviewed your techniques? I own a D610 and to me it is all the full frame camera I need. When it came to image quality it never let me down and I use it most of the time with a 28-105 AF-D or a 24-85 AF-S.

If you think you have "OK lenses" perhaps what you need is a good lens but to repeat it again, make sure you are using good photographic techniques before wasting your money. Jack Dykinga used to say "Concentrate on equipment and your images will be technically good. Concentrate on seeing the light magic colors and your images will stir the soul."

JD750 Loc: SoCal

So you want to buy gear that you won’t use on your trip?

Sounds like GAS to me but If you have money to burn then by all means spend away and enjoy it.

User ID

Right. Could be worth $1200 to be rid of that. The user would sleep much better knowing that their camera is a genuine "pro" model that boldly forsakes the pop up flash. Sleep is priceless.

tenny52 Loc: San Francisco

I also have the 24-85 AF-S on most of the time on travel as well. One of the reason for updating could be the low light shooting. A D780 would allow me to shoot at faster speed and instant focusing. Am I right about that?

tenny52 Loc: San Francisco

It is a GAS with itching fingers

tenny52 Loc: San Francisco

When I pass on, I can also pass on my D610 and the $1400 to someone who would not really care.

tenny52 Loc: San Francisco

yes, I just got my Insta360 x3 and am learning how to do the video editing. I will wait for another day when the stock goes up again

tenny52 Loc: San Francisco

The D780 would allow me to shoot at a faster speed, and instant focus, wouldn't it?

tenny52 Loc: San Francisco

that's what I want, shoot at faster speed and more reliable faster AF

CHG_CANON Loc: the Windy City

Instant focus? Probably not. The AF system is likely to be limited by (a) the focus motor of the lens and (b) the power supply of the camera. Typically, a battery pack makes a different to the highest end cameras in giving 'more power' to the camera. Changing the lens changes the lens focus motor. Battery packs cost another $100 to $300, based on the brand / model involved.

Faster speed? The reference to frames per second (fps) seems to be different than your usage of 'faster speed'. The D610 has a shutter speed limit of 1/4000 sec. The D780 provides 1/8000 sec max speed. Is shutter speed your meaning of faster speed, and is faster than 1/4000 sec relevant to your needs?

FPS? You have to be shooting still photos in Live View to achieve 12 fps for the D780, including a number of caveats on the file type and card type / model. Is LiveView even practical for sports, wildlife, etc? Otherwise, you're at 7 fps that doesn't seem like much for $1300 for just another 24MP Nikon full-frame DSLR.

reliable faster AF? Have you presented examples images and asked for help, aka free help? We can probably save you $1300 by just discussing your current D610 results. Maybe there is a need for another camera for your needs, where a D780 isn't the solution. But, we don't yet know the problem.

tenny52 Loc: San Francisco

Did you mean no difference, you meant at regular bright light when you can shoot around f4.5, at 1/160 & 100-250 ISO. and the speed of the focus also depends on the battery power?
When I meant speed, it is about shooting photos at faster speed on low light on auto ISO.

CHG_CANON Loc: the Windy City

I don't understand your clarification. The D610 shoots to 1/4000 sec. That is shutter speed, just like 1/160 sec is shutter speed. Do you mean "shutter speed" or something else when saying "faster speed". If you mean something else, what specifically are you referencing by faster speed?

You can probably save the 1000 words of explanation and the back n forth Q&A by instead presenting an example image of the problem you're looking to solve.

JD750 Loc: SoCal

Faster lenses can help with that.

JD750 Loc: SoCal

good luck! I fear we are going to be in a bear market for quite a while.