I recently inherited a Nikon F film camera with four lenses: a Nikkor-H Auto 28mm – 1:3.5, a Nikkor-H Auto 50mm – 1:2, a Nikkor-P Auto 105mm - 1:2.5 and a Nikkor-Q Auto 200mm – 1:4. I am considering buying a Nikon D750 with the intent of using these lenses. I understand all four lenses require an AI conversion to adapt them to the D750. The conversion will cost $100. Does anyone have any knowledge/experience using older (50+ years old) lenses on a current digital camera? Knowing my dad, I assume these were quality, high end lenses when he purchased them. Will these lenses give me the capabilities and sharpness I am wanting or am I wasting my money to do this? All replies will be greatly appreciated! Thanks!

As my photography education progresses, I am beginning to seriously consider transitioning from M43 to FF, primarily to improve DOF control, and low light shooting, as well as overall image quality improvement. It seems there’s a 3D quality to images produced by a FF sensor that I’d really like to achieve, and am currently not able to get with my M43. I currently have some pro glass, and I know there would be some improvement with fast primes, but I’m hesitant to invest more in this platform if I’m not going to stay with it. Since I’ve grown accustomed to an EVF, I’m looking at Sony (A7RIII) as a possible option. So, I’m wondering if anyone else has been in this position, what you decided to do about it, and what your results were. Thanks in advance for your help, I really appreciate any advice I can get.

By far the most widely useful filter for digital is a Circular Polarizer. It can do things for images that simply can't be done in post processing.

Most other filter effects can be quite easily emulated in post-processing software.

The reason for using UV filters on film cameras a lot was because most film was overly sensitive to UV light and would get a blue cast. The filter helped prevent that. It had nothing to do with lens "protection".

In fact, just how much real world, physical protection might you expect from a thin piece of glass? Plus, lenses are a lot tougher than people think. (Far tougher than the filters people are sticking on them!)

Watch and learn: https://www.youtube.com/watch?v=P0CLPTd6Bds

All that said.... Yes, I've got quality, multi-coated UV filters to fit my lenses. They're stored separately until actually needed, until they might actually serve a purpose. Which really isn't very often. If I'm out shooting in a sand storm (unlikely), I'll use them. Next time I'm shooting a paintball battle (also pretty unlikely), I'll use them. When I'm at the beach, a bit more likely, I'll use them (salt spray gets on everything and is difficult to clean off). I might even use them for a scenic shot where there's a blue haze that the UV filter can reduce (which is why I carry UV filters, instead of plain clear ones). But since they are so rarely needed, they were low priority for me.

Shooting through an extra layer of glass will always degrade you images to some extent. With a high quality, multi-coated filter, under most lighting conditions the "loss" is so negligible you're unlikely to notice. But under more strenuous lighting conditions, the filter can cause problems. I had to "fix" flare issues in 1200 images made in strong backlit conditions by a second shooter I'd hired for a job, when he ignored my request he remove any and all filters from his lenses. That was many hours of unnecessary work. No filter should ever be used directly shooting sunrises or sunsets, either.... extra layers of glass cause various types of flare problems. Especially avoid using a multi-layer filter like a Circular Polarizer. It's also bad practice to unnecessary stack multiple filters on lenses... which means any time you want to put a useful C-Pol on a lens, you have to first remove a mostly useless UV filter.

So while I have them for situations where they serve a purpose, they are not on my lenses all the time... very rarely, in fact, and acquiring UV filters for my lenses was pretty low priority, in the overall scheme of things.

Your highest priority should be a quality, multi-coated C-Pol. For their price, the best are B+W F-Pro (8-layer multi-coated) and XS-Pro (16-layer multi-coated, slim frames for ultrawide lenses). No one makes better and you can easily spend 1.5X or even 2X as much and not get as good a filter. Another brand that are identical in all respects cost nearly 3X as much.

Another type of filter that's useful with digital are Neutral Density. These are rather specialized, though. One or two strong ND filters can be used to allow slower than normally possible shutter speeds and/or larger than normally possible apertures in relatively bright light conditions. A couple ways these are used are to make running water in a stream look "creamy" or to be able to shoot portraits with shallow depth of field effects such as a strongly blurred background. Personally I have far less use for ND and these special effects, than I do for C-Pol.

You also may not need filters for every lens you own. For example, I almost never put a C-Pol on any of my longer telephotos. I also don't recall the last time I used one on a macro lens. I tend to use them mostly on normal to wide angle lenses, simple because the types of things I shoot with those lenses are more likely to need the effects of a C-Pol. They also can be useful for portraiture (short telephotos), architectural or product. photography.

The effects of most filters can be done just as well or even better either by the camera or in post-processing software. For example, the ability to set white balance, or even let the camera set it automatically in a lot of situations, means that color correction and color conversion filters are unnecessary. The same with black and white effects filters, which can be easily emulated in Photoshop and other software. Graduated neutral density effects are far better done in software, too. In fact, with digital the same sort of technique can be applied to images where it was impossible to use a Grad ND. Forget warming filters too. In fact, if you set a custom white balance or even let the camera do an auto white balance, any warming filter on your lens will be cancelled out. There are ways to get the same effect using tinted targets (Warm Cards and similar) to set a custom white balance.

And I as said at the beginning I don't want to spend a lot of money in a hobby where I will get ZERO money back.
Then I have been thinking about a TC.

About losing light: I don't know if it will affect my photos.

About AF: this is really not a problem, 99% of my shot until now I've done manual focusing.

About Tripod: I have one cheap that I use for my GoPro (I'm a goalkeeper and I use a GoPro behind my goal at the training) but I'll buy a better one very soon. The one at the link below I guess.
http://cdon.no/elektronikk/manfrotto-stativkit-befree-kulled-new-alu-gron-p39834259

Do you know a TC that doesn't costs more than 150$ and can be use with my Nikon D3400 with a 70-300mm?