High-Power 500mm f/8 Manual Telephoto

Comments

• bruto

  September 2017 edited September 2017

  I am guessing this is an inexpensive, T-mount lens. I doubt you'll find much help on this. There are a number of quite inexpensive manual telephoto lenses of this sort, and you're likely to find it quite challenging to use well. Alas, there's a reason why the best of these lenses are forbiddingly expensive.
  
  Since such a lens is entirely manual, you must, of course, use manual mode on the camera, and presumably it will also not interact with the camera's meter. It will also require a tripod to hold steady enough, as there is no vibration control, and the longer the focal length, the harder it will be to hold steady.
  
  It will help if you enable the "overview" function in the replay menu. This will give you a histogram of your exposure, and function as a post-shot meter. Take a picture, look at the histogram, and adjust the exposure so that the information on the histogram falls roughly between the two ends. Bunched up to the left is underexposure, and bunched up to the right is overexposure. When you enable different replay options you can toggle through them with the up/down arrows on the rear control.
  
  You can start with a "sunny 16" guess. In bright, open sun, a likely exposure will be at F16 and a shutter speed that is the reciprocal of your ISO. So, for example, on a sunny day, you could try ISO 200, F8, and a shutter speed of 1/400. Exactly how much to increase exposure for clouds, shadows and the like is hard to say, but on a cloudy day I'd add a couple of stops (double and double again), so maybe ISO 400 at 1/200, or a similar combination. Exactly where you end up will depend on whether you can hold steady at a given shutter speed, and how much ISO noise you can tolerate. Note: the term "stop" is still used, a holdover from the days of manual cameras and a way of keeping the changes of ISO, shutter speed and aperture equivalent. A "stop" is defined as a doubling or halving of exposure. ISO is changed by a stop when halved or doubled, and a doubling or halving of exposure time is a stop. Apertures are not so intuitive, but the progression from F8 to F11 to F16 to F22 is one of full stops. The camera's own adjustments are by default in 1/3 stop increments. Three clicks of the shutter speed wheel will equal one stop.
  
  If you're using a tripod, as you almost certainly must, you might find Live View works better. The maximum aperture of F8 will make viewfinder focusing difficult on a small DX format camera. If you shift to Live View, you can zoom in on the image in the finder (this won't change the image you take, only the part you see in the finder) and finely adjust the focus.
  
  With all that said, some of those lenses are not too bad optically. It's likely to be quite simple internally, and not terribly well corrected for chromatic aberration and the like, but it can be reasonably sharp at center if you're careful. But it's unlikely to be very useful for action or moving wild life. The better the tripod, the more likely you are to have some success here. The slow aperture will make it a challenge both to focus sharply and to get a shutter speed fast enough to combat vibration. You can up the ISO to get a faster shutter speed, but doing so will increase noise, so you will likely have to compromise.
• kristie

  September 2017

  Thanks, for taking the time out to answer my question. I have been reading a lot on this type. I just received it, and I will use your suggestions and see how well things turnout. Again, Thank you. I'll let you know how it goes.