2X converter for my D40, need help finding one.

[artmustel]

Hello!

I have a Nikon D40 with its 18-55mm kit lens, a Nikkor 50mm 1.8 lens and a Nikon 55-200mm VR lens.

I wonder if there is a 2x converter that would keep the autofocus function in my D40. If not, which one should I buy that at least keeps the metering functions on my camera? My main interest is using such converter with the 55-200mm VR lens. Please let me know which one will work the best for me.



Thanks!

[rjseeney]

A 2x converter will put you past the point of auto focus with the 55-200 at 200mm, as you lose 2 stops of light with a 2x converter. You'll also likely degrade image quality significantly. Converters do not work well with consumer grade lenses. converters typically are for fast primes, or constant aperture zooms.

[artmustel]

Ok, RJ, I understand perfectly your point and appreciate it very much.

Now, I would like to purchase a 400mm lens (minimum). I do not need a zoom, I do not want extreme apertures since it is going to be pretty expensive and my main interest at this time is shooting nature pictures, only as a hobby. Can you suggest anything, preferibly from a third party manufaturer? I do not need the autofocus but I would like to have the metering functions.

Thanks!

[rjseeney]

What is your budget?? 400mm lenses typically don't come cheap. They are also quite large and heavy so you'll have to consider picking up a tripod as well.

[artmustel]

I think a tripod is a no-no for me.

Do you think a mirror lens (500mm) would be too bad? At least they don't look so big. There are several brands at feebay, one of them the Opteka for around $100 with shipping. (f8). There is another brand that I don't remember now, for around $180.00, f6.3. I've seen 400mm (not mirror) used, for under $200.00, usually off brands, non cpu.

My budget for this is very limited, I would say $200.00 maximum. Thanks!

[Bob Nichol]

When it comes to lenses: Fast. Good. Cheap. Pick any two!

Mirror lenses (AKA Catadioptric system http://en.wikipedia.org/wiki/Catadioptric_lens) are a mixed bag, no autofocus, only one aperture setting (f/6.3 in your example) so you can only use ISO and shutter speed to adjust exposure, and out of focus highlights that look like doughnuts. They are not stabilized and are generally slow which makes for slow shutter speeds if you can't boost the ISO enough. Slow shutter speeds means tripod if you want decent image quality.

$200 for a used 400mm sounds like a pig in a poke. Lenses usually keep their value better than that. At a guess you may have to use manual focus and exposure, and maybe even manual stop-down when shooting. This refers to the fact that most modern lenses keep the aperture open for composition and focus then close it automatically when the shutter release is pressed. Some older and cheaper lenses don't have this feature so you have to remember to close the aperture to the shooting setting before you press the shutter release.

DSLRs in general are set up for autofocus so don't have the focus assist features on the focus screen which makes it harder to manual focus.

$200 for a lens doesn't allow for much quality especially in the 400mm range.

[tjsnaps]

The Opteka you are talking about is a preset lens. Their in no auto diaphragm This means that you must set the f stop on the lens manually before you take a picture then open it back up again for a bright image in the view finder. You will have no in camera meter and will have to focus manually. The one advantage is that without the mechanics of a normal lens preset lenses tend to be smaller and lighter. These lenses are normally T-mount which means you must buy an adapter for the camera brand you use.

These lenses are not the greatest but may not be the worst either. I have an old Komura 300mm preset that is quite sharp.

As for manually focusing on a D40 this may not be easy. ON my D50 the focus indicators work but they are touchy. And may not work with slower lenses.

[artmustel]

Indeed you are right.

Maybe I will need to get a 300mm instead.

What about this one? I know I won't get autofocus with it:

http://cgi.ebay.com/SIGMA-70-300mm-D...QQcmdZViewItem

[tjsnaps]

That lens would work but in all honesty unless you get a really good deal (that auction has 6 days to go ) you would be better off getting one that will auto focus. If you're going to buy from Ebay be patient. You might have to pass over a lot of lenses but the deals can be found. Use the "watch this idem" feture.

[NHL]

artmustel wrote:

I think a tripod is a no-no for me.

Do you think a mirror lens (500mm) would be too bad? At least they don't look so big. There are several brands at feebay, one of them the Opteka for around $100 with shipping. (f8). There is another brand that I don't remember now, for around $180.00, f6.3. I've seen 400mm (not mirror) used, for under $200.00, usually off brands, non cpu.

My budget for this is very limited, I would say $200.00 maximum. Thanks!

Why not get a Nikon version?
http://mirrorlens.blogspot.com/2007/...kor-5008s.html

I got my copy for $225, but I've never seen theses old Nikkor commanding more than $300... especially their older and larger one with no macro capability - I've posted some test shots recently: http://forums.steves-digicams.com/fo...mp;forum_id=66

It depends on what you shoot but for wildlife or other small subjects IMO you need at least a 400mm to have a narrow enough of a field of view for a tight crop (to mask out the background) and to get a narrow depht of field to 'pop' the subject from the surroundings. If you can't afford a long tele then you should definetely give the 500mm mirror lens a try despite its drawbacks (manual focus and fixed aperture):
1. From my experience one rarely shoots a 500mm wide open (i.e. @ f/4) anyway because its DOF is so shallow that one wouldn't get the entire subject in focus so f/8 for a CAT is not that big of a deal.
2. A mirror lens is also simpler to make as it will be less prone to CA as other multi-elements optic, but what's best about it is it portability - I'm quite amazed by its compactness when compared to my EF-500 f/4L IS or Bigma. It's also so much shorter (and lighter) than my EF-100/400L IS as well!
3. Contrary to others opinions, I've found it quite enjoyable to manual focus a 500mm reflex lens with modern AF dSLR brighter micro-screen... With my manual focus SLRs half of their split-screens blackout with lenses above f/5.6 and their viewfinder became darker than my D300...
-> BTW the center focus point will lit up as an aid if the manual lens is focused
4. Even on manual with Auto-ISO the Nikon is still an automatic camera and this work great with any manual lenses

Shot just yesterday with the 500mm f/8 mirror - Again I just want to point to the fact that no VR (or tripod) was required even though my shutter speed was only 1/200s for a 500mm. The flash did the trick in freezing my handshake and this image would have been ruined by the strong backlit if I had rely only on IS/VR:







The issue here is poor lighting which leads to slow shutter speed:
VR addressed the slow shutter speed so one would get a sharp image but did not fix the heart of the problem which was inadequate lighting
-> A flash not only remedied the original lighting issue but also removed the need for VR!

How can you go wrong for about ~$200??? :-):-):-)