Catadioptric (mirror) lens

Has anyone used one of these alternative tele-lens, on the D70? I

looked through one that was mounted on a film camera, this weekend,

and fell head over heals for it. So bright and light. Is was you

see, what you get? And can they be used on digital cameras?

Appreciate your feedback on this...

Mirror lenses would be advantageous on dSLRs to some extent because they are essentially free of chromatic aberration, a flaw that many dSLRs can exaggerate ruthlessly. This is useful for astrophotographers as well.

 

Most mirror lenses have a slow fixed aperture that makes for a dim viewfinder and difficult focusing. However a camera with a focusing indicator can help.

 

The better mirror lenses can be very sharp. That would include at least the later model Nikkor. The lesser lenses are pretty lame and no bargain at any price, such as the $100 Vivitars, Samyangs, etc., all of which are probably made by the same handful of anonymous Asian Rim manufacturers and resold under various brand names.

 

All of them demonstrate the characteristic "donut" ring out of focus highlights. However if the background has no bright highlights (water, glass, metal, dappled sky or sunlight through foliage, etc.) you probably won't even notice the donuts.

I don't usually worry about bokeh but mirror lenses can render the worst of all

bokeys.

BTW, while a Nikon mount mirror lens can fit on your D70, it probably won't meter unless it's chipped (that's assuming it's even possible to chip a mirror lens - I don't know).

 

However, if you're using the lens under consistent lighting, you can meter using another lens, then switch to the mirror lens and continue shooting. Checking the histogram and highlight warning screens will let you know whether any minor adjustments are appropriate. I don't continually meter when I'm shooting with my Canonet or Olympus rangefinders or Rollei TLR. I meter for the average scene and occasionally when it appears the light has changed. It's usually good enough.

 

Consider also that focusing with a mirror lens can be challenging. The mirror lenses I've handled vary tremendously in focus damping (resistance to turning and smoothness of that resistance) and focus throw (how much you have to turn the focus ring from infinity to minimum focus). If it has a short focus throw it will be quick to focus but twitchy to focus accurately. If the focus throw is too long you'll be cranking it like the starter on an REO Speedwagon.

 

If a maximum focal length of 300mm is good enough, tho', you might consider the 70-300 ED version of the AF-Nikkor. It's no larger or heavier than a mirror lens, will definintely meter with your D70, is well corrected against chromatic aberration (don't get the cheaper non-ED version, it's false economy), and surprisingly sharp and contrasty across its focal range and aperture range for a relatively inexpensive lens. If I used a D70 it would be on my priority list. However since I lug around a D2H that's as heavy as a cinder block, the light weight of the 70-300 doesn't really offer much of an advantage to me.

 

While the 70-300 ED AF-Nikkor doesn't have the speedy and quiet Nikon Silent Wave Motor (SWM) of the AF-S Nikkors, it still focuses pretty quickly. I've seen sharp photos of birds in flight taken by other photo.netters using a D70 or D100, so it can be done.

 

Just a thought.

Don't bother wasting any money on these. Most are crap. Even the best of the best will never come anywhere close to a refractor.

 

Nikon does not have a mirror lens in its line up any more.

Catadioptric telescope can be diffraction limited; as good as a optic can be. A common failure mode with a mirror optic is poor focusing; no hood used; camera shake; stray light; warped tweaked distorted mirror mount; due to abuse. . The better mirrors can be quite good on axis; but often drop off in resolution going off axis.

500/8 Adorama is about USD720, or USD770 at B&H.

Several are listed at the KEH site - used, of course - for much less money.

 

I have used this lens in the not-too-distant-past. They can be sharp enough though contrast is lowered.

 

and some people object to their OOF properties, though if you have the right background, it's not all that bothersome.

 

I had no problem with focus but then the lighting for me was bright and

even and I was using an F3 with a 6X chimney finder. It was OK for

me when I switched to the standard HP finder as well.

 

What Kelly Flanigan wrote. David Ruether has a good explanation of this

lens on his website, and, of course, this forum has a lot of useful information.

 

As to how this might work out on your digital camera, I have no idea.

In the best case they have a fixed and very slow (even slower than nominal, due to central obstruction) aperture, poor contrast and unattractive backgrounds. That's the higher-quality ones. The cheap ones are just junk.

I want to thankyou all for responding to my query. Lex, I already own the 70-300 ED Nikkor. Have lots of fun with it, want more. Vivek, Kelly, Yoni; B&H and Adorama have a Nikkor (mirror) 500mm listed (w/hood) 1)used (E+)$640USD. The one I was interested in is by Sigma just because it's reach is 600mm, which is going for $400USD @ B&H, $350 @ Adorama. After reading these posts I think everyone agrees if it must be so then let it be a name brand, such as Nikon. I really want that extra 100mm, for bird shots that I have come to enjoy so much. I have a really bad back, so the lightweight is what I am searching for. Thankyou Peter, for taking the time to post the photograph. I like it.

~

You may want to rent one; shoot some images to see if they do what you want.

I have said this a number of times before, the main problem with mirror lenses is that they are very slow. A 500mm/f8 lens, mirror or not, is going to give you a very dark image in the viewfinder and it is difficult to focus it manually. The viewfinder of the D70 is simply going to compound the problem.

 

As Kelly suggests, try it youself before you buy it. That is the best way to tell for sure.

I'll look into renting one. Sound advise. Our local shops have no loan policy. I think one of the online sites do. B&H? Thanks Kelly & Shu...

Charlene; a small camera shop owner if they have one will usually allow you to shoot few snaps outside; making sure you dont run away. :) :0 renting or shooting a few snaps with your camera goes along way to see if the lens fits your needs. Folks do this all the time with shoes; or buying a car. Long ago there were many slower long lenses with Nikon; in mirror and lenses. There was a so so 500mm F5 mirror unit; a 1000mm F6.3 sos so mirror unit; a 1000mm F11 mirror unit; a 2000mm F11 mirror unit

a 200 to 600mm lens F9.5 zoom; a 200 to 600mm F9.5 10.5 zoom; a 500mm F8 mirror; a 1200mm F11 lens; a 800mm F8 lens; a 600mm F5.6 lens; 500mm F5 lens; a 3 element job that also worked with the Nikon rangefinder with a reflex adapter. With the old Nikon F and F2; one used screens that worked better with long lenses; to gain snappier focusing. <BR><BR>With a modern slr; some models have darker screens; you might be REAL disappointed; hence the trial /rental is a way to see if the lens fits your needs.

Charlene,

 

Yes, I checked again and you are right that Nikon does have a 500mm mirror lens (manual focus, no matrix chip and no metering possibility with your D70) in its current line-up. I have used a few mirror lenses and even with a matrix chip (to have accurate metering), the image quality is much less than the ones from a zoom and a 3X converter. This is no exaggeration. You can get images like the example posted if you have the lens set up on a stable tripod and metered accuartely. This gives you nice outlines and no details.

When one adapts an eyepiece to a cat Nikon 500mm; the very center can be diffraction limited when used as a telescope; using double stars as a criteria. In practical usage; the off axis performance with a cat mirror falls off axis. I never had had this super bad experience with using a Nikon 500mm as others have mentioned. I have seen super poor performance with the off brand names; or when too low a shutter spped is used. A typical problem with a longer lens; glass or mirro; is that one shoots thru a long air path; and gets heat waves; lower contrast images. A cat mirro unit is very sensitive to a temperature change. Performance will be bad during the period of temperature change; if the mirror has a temp differential across it.

I get the general drift of this thread, and I would like to second the comments about the cheap lenses (a vivitar non-cat sits in a cabinet, I can't even bring myself to sell it - it is so bad). I know also that there are various Zeiss mirror lenses that range in price from $1000 to $30,000.

 

However, there is a middle ground - what about the Celestron 500MM or the Questars. I wonder if the questars might be as good as the Zeiss at a much better price (or not, I don't really know their prices).

 

Any experience??

 

Brad

Brad, I can't answer directly right now, but Charlie Barringer, who lives the next town over, has two (2) Questar 700s and, I think, some CZ mirror lenses and some enormous Zoomar mirror lenses. I don't know if he's shot them against each other, but he's keeping his Questars. If you don't know who Charlie is, use Google.

 

He's away now. You've piqued my curiosity. I'll ask him after he's back. Understand that other things equal, f/4.5 is sharper than f/8.

 

FWIW, I have a Q700 m'self and am very happy with it, subject to the difficulty of using any long lens well. "Atmospherics," vibration, and subject motion are killers. So is aiming.

Thankyou to everyone for contributing your thoughts and expertise. There are no small or large "shops" anywhere near, to rent from. I just wanted something lighter than the norm prime. (bad back) Will certainly give it more thought. And with time, who knows...

Thanks again, ~charrise

<p>I had a Sigma 600 f/8 cat lens that I just sold (for a reason I can't recall at the moment). It was sharp and I loved it. There are several for sale each week in the $200 range; cheap!</p>

 

<p>The no-chip and therefore no metering thing was a problem on my N80 and I did a lot of the meter with one lens then change to the mirror lens for the shot. All that hassle disappears in the DSLR Age. Just use the histogram as your meter. Take a sample shot, judge the exposure by the histogram, adjust accordingly and reshoot. Simple. This is my daughter on Captiva as seen by my D70 through my 600/8.</p>