Looking for a 800mm lens which is sharp, any advice???

mioandhiscats · Joined: 25 Jun 2015 Posts: 11

I do not have a big budge. I have 2 plans, one is Kenko 800mm f8 mirror lens, another is a nikon 300mm f4.5 with a 3X multiplier.

I have never used Kenko 800mm f8 before, do not know if it is sharp enough, can anyone post some pics taken by it?

Or anyone has better advice?(as cheap as possible)

Thanks!

vlousada · Joined: 11 Dec 2010 Posts: 345 Location: Portugal

Hi,
I do not have any experience with the mentioned lenses, however if I want to be cheap I would consider a third Option: a 400mm with a 2x tele-converter!

note1: Hardly on a budget you will get a faster aperture than f/8 with that combo, but a GOOD and fast mirror 800mm is not cheap either.
note2 (EDIT): maybe the MTO 1000mm f/11 would worth for consideration

calvin83 · Joined: 12 Apr 2009 Posts: 7576 Location: Hong Kong

If you go for the non-reflex opinion, a 400mm F5.6 and a 2x teleconverter will be better.

Attila · Expire: 2025-11-18

Get closer to subject , best option Sad

above 400mm quality is dramatically fall off

asfethan · Posted: Thu Jun 25, 2015 4:56 pm Post subject:

3x multiplier is too much in my opinion because multiplier slows down the lens. You'll have f13.5/900mm but with sharpness of f4.5 at largest aperture and some IQ loss. If you'll want to stop it down eg. to f8 you'll get amount of light passing to sensor which equals to f24 with some IQ loss. I can't imagine situation where you can use this setup except one - moon shots.

marcusBMG · Joined: 07 Dec 2012 Posts: 1318 Location: Conwy N Wales

Sounds like your looking for high magnification.
These days there is another option: a good lens used with a camera with a small sensor. For example check out these pics taken with the pentax Q:

http://www.pentaxforums.com/forums/122-lens-clubs/55946-300mm-plus-lens-club-discuss-your-long-lenses-1149.html#post3294723

In my opinion you are likely to be unimpressed with the results from options involving large slow mirrors, or TC's

I have got quite decent results from my M4/3 lumix G1 with a tamron nestar 400mm f6.9 acquired for less than $50 - 2x crop factor = 800mm.

mioandhiscats · Joined: 25 Jun 2015 Posts: 11

Thanks guys!

I have D610 and NEX.

Actually I prefer to a mirror lens which is sharp enough. I know most mirror lenses are not sharp at all, but if anyone can offer some pic, it will be better for me.

Attila · Expire: 2025-11-18

MTO 1000mm f11 is a sharp lens, need very sturdy tripod

calvin83 · Joined: 12 Apr 2009 Posts: 7576 Location: Hong Kong

mioandhiscats · Joined: 25 Jun 2015 Posts: 11

mioandhiscats · Joined: 25 Jun 2015 Posts: 11

vlousada · Joined: 11 Dec 2010 Posts: 345 Location: Portugal

Attila · Expire: 2025-11-18

I mix easily names , apertures Laughing

only one type MTO 1000mm is exists

asfethan · Posted: Thu Jun 25, 2015 7:21 pm Post subject:

CuriousOne · Joined: 31 Dec 2013 Posts: 669 Location: Home

I have that MTO-11. Image quality is not bad, I'd say it resolves 6-8 megapixels. But focusing ring is stiff, requires re-lubing, which I'm lazy to do. If anyone interested in getting this lens for a low price, PM me.