Yes you have read the title correctly. I have just bought a 500mm lens for less that £100 off Ebay including postage. The question is will it be any good?
So the lens in question is a Samyang 500mm f8 Mirror Lens. I think they cost about £150 brand new for what I have found online. It was the price point that initially pricked my interest. I have owned a 500mm lens in the past. That was an amazing f4 Canon Prime and it was a beast of a lens, the optics were amazing, image quality brilliant and at over £5000 the price was eye watering. At a tiny fraction of the price I know that the Samyang won't be anywhere near as good, however I thought this might prove to be useful for anyone considering buying one.
So here is the lens in question. The first thing that you will notice is that it looks a bit like a telescope in the optics. Thats the mirror which collects the light, bounces it up and down the lens casing before it arrives at the camera sensor. That is how they achieve the 500mm focal length is a lens that is about 15cm in height. The next point of note is that you have to use a T adaptor which comes with the lens to attach it to you camera. This is exactly the same process that you use when attaching a camera to a telescope.
The lens is totally manual. No auto focus here, you are going to need to do everything yourself. However using live view of the back of your camera make this job quite simple. Aperture wise, you are going to at f8. This is the only option. As you can imagine then, this lens isn't going to let a lot of light into it. Build quality it seems to be ok, some sort of cheap metal construction but in no way will be it weather sealed.
With no image stabilisation and not being a fast lens then without bumping the iso up to really high levels then achieving a fast shutter speed of over 400th second is going to be pretty impossible. If you do increase the aperture then, the noise in the image will increase significantly. At 500mm hand holding the lens is going to be a real challenge to get any sort of sharpness. So that means you are going to have to use a tripod to overcome that issue.
Does that lens have any purpose then? Well without autofocus you are not going to be able to use it for wildlife or sports. You could do portraits but why would you do this at 500mm? So it leaves you with 3 areas - landscapes, astro and macro. At the time of writing I have tried any sort of landscapes or macro photography. For landscapes it will certainly compress the image which some people may like and the 500mm reach will also provide some benefits. Macro wise then it will give you the option to photograph insects that are perfectly still without the need to get close to them. I will test the lens for both of these areas over the coming weeks.
I have taken 1 image so far which is below. In my opinion I would give the image quality about a 2 out of 10. It isn't sharp despite being perfectly focused. The image will have lost a bit of clarity due to the crop. I did also take a quick image of a church spire from the back garden which didn't need cropping. This image was certainly sharper but still appeared to be soft. Chromatic aberration was very evident.
So that's it for now. Will I be keeping the lens long term? No, not for the reason mention above, its just that I don't need it but want to see what it was like. Is it worth the money? For a beginner or someone wanting to experiment with a long focal length who isn't over concerned with razor sharp images that they will publish then absolutely. Being totally manual it will also help with you understanding of the the exposure triangle and it is probably a good cheap first step into the world of astro photography. You would pay a lot more for a telescope. A second hand one off eBay of even a brand new one is not going to break the bank and its a fun lens to play around with so long as you are not expecting earth shattering results.