I have a cheap ($40) Vivitar SF-4000 flash for the side light. It is light and nice for travel. I have used it as a slave. But now somehow it fires, but very very weak light. Just can not figure out why.
So, I would like to buy a cheap flash which will work as a slave BUT ALSO as a main flash. It means a slave type but without the need to fire the one on camera main flash nor with a cable connection. I would like to play with the portrait against the black backdrop.
I know, I can use a camera w/o flash and hang two-three pocket lights to get the side illumination … but . My camera is Nikon 7100 . Maybe there is a wireless feature in it .

Any advice will be appreciated.

Thank you Miro

The son of a close friend, is a marvelous “sketch artist”. Around Christmas-time, I offered him a Fuji x-A3 that I own.my thinking was that a great artist of any”persuasion” could benefit from owning and using a camera. He wasn’t comfortable taking a camera and lens from someone “HE” didn’t know so he didn’t take the GIFT...THEN.... now he has concluded that doing some “infra-red stuff might augment his “ARTISTRY”, but I know nothing about “infra-red” and would like to find out whether or not, he could convert a fugi mirror-less, to take infra-red images, before I give him the kit. The kid (27 years old) is without a doubt, the most talented artist I’ve ever personally known and I would love to CONTRIBUTE. Can anyone enlighten me a little about infra-red image-making?? And can this camera do the job??.......................................RJM

I hope that you've ordered this camera already. I have a D500, D810, and D850. The D810 is a great first-line camera, and while the D850 adds some new features, there are absolutely no basic photography duties it can do that the D810 cannot. The D810 has a full magnesium alloy body, while quite a bit of the D850 is of composite construction. I no longer think that there is a big advantage one way or the other, but it is a difference. The D850 has a little better dynamic range, but the D810 has a very smooth, quiet shutter mechanism. The D810 will handle probably 98% of any conceivable task you would ask of it.

The D810A is a wide-spectrum camera optimized for astrophotography. Its sensitivity extends into both the infrared and ultraviolet portions of the spectrum, with the result that it is not usable for ordinary visible-light-only photography. Nikon makes that statement very clearly on their website. Conversely, I am unaware that there is any way at all to achieve the astro capability in the main line D810.

Just as a final note...the D500 and the D850 are operational twins. Control layout is identical on both cameras, and the menu structures are the same, except for some of the newer functions available only on the D850 (slide/negative copying, focus stacking, etc.). The D810 physical layout has some key differences...I'm coming to like the new layout better. The D850 also has a new sensor design, which is more evolutionary than revolutionary, in my experience, and it also has a little bit higher pixel count and more video options. It also uses opaque masks in the viewfinder when using one of several non-full frame formats instead of simple lines. I find that pretty helpful. Others will tell you that it also offers better autofocus functionality, which can be a big plus depending on what you are shooting.

Good luck as you decide. If your main interest really is the astro functions, this one won't work. Otherwise, it could likely be a good choice for you.