Can sliding apertures on zooms die? And stay dead? Please?

You what, guv?

 

 

The same idea as for mounting lenses. Threaded mounts are all gone. But that change never happened for filters, alas.

 

 

 

 

It doesn't always work that way. Sometimes you can't take a new reading after zooming, for whatever reason. Sometimes the only way to take a reading is to either use an incident meter or the LCD, and having to compensate after zooming is troublesome.

 

 

Except that the smallest aperture at the wide end can be, say, f/22, while at the long end it can be f/36. Perhaps not a massive deal, but yes, I do know what I'm talking about. But I don't want to be unfair to people such as yourself. Not all photographers have extensive technical knowledge, and many don't care. To each his own!

 

 

The average consumer is probably very happy with their dual-lens smartphone. Should they be? It's up to them.

 

 

Oh, Gary, Gary, Gary.

 

 

The lens I use the most is a constant aperture tele zoom (not going to give that away, as it's my super secret lens of intrigue, which is something very different from state sponsored life insurance). It's cheaper than the sliding aperture kit lens that came with my camera. I have another tele zoom with a constant aperture, and it is a bit more expensive, but worth about the same as that kit lens. Caveat: they are both manual focus.

 

 

All lenses except catadioptric (mirror) lenses have variable apertures. For the most part. Smartphone lenses don't, for example. But there is a difference between 'variable' and 'sliding'.

 

The other flaw with most zooms is that they are varifocal, instead of parfocal. That means that you have to refocus after zooming. Not a good thing, but AF does take away most of the sting, if you use AF (though I wouldn't know). But, unlike with constant apertures, making a lens parfocal seems to be more involved and therefore much more expensive. That is to the best of my knowledge.

 

 

Let's remind ourselves of how many filter sizes there are!

You're right, there are a lot of different filter sizes, not a surprising fact given the different physical sizes of front elements due to lens speed, etc. Some manufacturers used to have a "standard" size for most of their lenses--Nikon had 52 mm filters for a lot of their lenses back in the day, and Pentax used to use 49 mm for most of their M series lenses under 200 mm. Now, not so much. But at least there are multiple choices from no name brands on eBay to camera makers and the German stalwarts like Heliopan and B+W free to make filters for any lenses on the market, no matter who makes them. Would you rather pay for 82 mm filters for every lens when much smaller filters would work? I wouldn't. And if you do have large filters there are always step down rings for smaller diameter lenses.

 

(snip)

Also, let's not forget that the "variable aperture" phenomenon isn't restricted to zoom lenses. All lenses have some light loss as you move away from infinity, although in 35mm format cameras it's usually not all that significant until to you start getting into the 1/2 lifesize range.

 

All of that aside, my electronic Nikons, both film and digital, correctly compensate for light lost in variable maximum aperture zooms and in macro lenses at close focusing distances. If I set a lens to f/5.6, for example, the camera is "smart" enough to hold it at a f/5.6 regardless of where the zoom ring is set or how closely I'm focusing.

 

Technically the change with focus, sometimes called bellows correction, isn't a change in aperture, as f/numbers are defined based on focal length, even when not focused to infinity. But yes, it does get darker.

 

Also, many cameras will let you set the aperture based on the current focal length. You then zoom, and the number in the viewfinder changes, even in A or M mode.

 

I might set a shutter speed based on what I can hand hold, and at maximum aperture, then zoom when the maximum is different.

 

But mostly there isn't a good solution, without losing useful aperture range.

Technically the change with focus, sometimes called bellows correction, isn't a change in aperture, as f/numbers are defined based on focal length, even when not focused to infinity. But yes, it does get darker.

 

Fair enough on it not being an actual change due to a change in the real aperture-it's more a real-world application of the inverse square law of light intensity due to the image circle becoming larger as you move the lens away from the focal plane.

 

Even though it's not a "real" change, I like that Nikon makes it easy by reflecting the change in the cameras controls. Mamiya was also nice enough on the RB67(and I'd guess the RB67) to give you a scale on the side of the bellows to show you the amount of exposure correction needed. It does get really fun on 35mm SLRs when you're using manual bellows. Of course, on large format it starts to become even more important in the studio-if you consider that a persons head is a little larger than 8x10, that means a head shot on 4x5 is about 1/4 life size, while on 8x10 it is only slightly less than life size.

a couple of examples of high end kit lenses doesn't represent anywhere near the whole field

My point was you can't rule out a lens because it has a variable aperture, nor accept a lens with a constant aperture without question.

 

BTW, I have a CF40, which is not quite as large as the older model (C40). It's not much of a wide angle with a digital back (60 mm equiv), but it helps. I never bought a screw-in filter for it, but I do have an adapter for a compendium shade, which can hold square gel filters. I recently purchased a Sony PZ 28-135/4 for video. It's an amazing lens, and the range covers most applications without lens changes. It takes a 95 mm, screw-in filter, starting at $90 for a UV filter. It's also constant aperture, no focus breathing, stays in focus when zooming, and has a power zoom for remote control.

I can't believe that after I just said you mentioned high end variables that aren't "kit" lenses, I then called them kit lenses. sheesh. Anyways, Ed, I have a question for you? Have you ever, or know of anyone that is shooting Hasselblad CF lenses on Fuji X camera mounts? I've seen adapters for that, but haven seen any photographic results. Just curious because I have a CF 80mm I would like to try. I'll have to get the Hassy out again and shoot some film some time, but I'd like to see what it looks like on my mirrorless since I can't really afford a digital back for a 503 CW. I know this may be off topic and apologize for that.

Sorry, but I have no information regarding using Hasselblad lenses on a Fuji X. The Fuji has its own shutter. You can leave the lens shutter open on the CF lens and close the aperture manually. using the preview switch, but there's no way to fire or cock the shutter with the camera.

 

I wouldn't expect extraordinary performance. While Hasselblad lenses are very good, they are designed to work with a much larger image area. Although you can't compare MTF data directly, Hasselblad lenses run in the mid 80's, whereas small format lenses often run in the mid to high 90's. Given the high quality of Fuji lenses, I wouldn't spend a lot of time fussing over this adaptation.

Thanks Ed, I was thinking something similar. The Fuji x lenses are pretty nice, at least the primes I've been using. Ok. Cheers.

All lenses have some light loss as you move away from infinity, although in 35mm format cameras it's usually not all that significant until to you start getting into the 1/2 lifesize range.

Cinema lenses - proper ones - don't breathe, and so maintain their transmission through the indicated focus range. But most photographers don't use lenses like that.

Cinema lenses - proper ones - don't breathe, and so maintain their transmission through the indicated focus range. But most photographers don't use lenses like that.

 

I'm not sure if you understand the physics behind what I'm saying.

 

Unless cinema lens makers have found a way to allow their lenses to transmit MORE light at close focus distances, it's physically impossible at close focus to not have light loss vs. infinity(there again, that whole inverse square law and enlarging the projected image circle).

Unless cinema lens makers have found a way to allow their lenses to transmit MORE light at close focus distances, it's physically impossible at close focus to not have light loss vs. infinity(there again, that whole inverse square law and enlarging the projected image circle).

This can be accomplished using floating elements. Remember, it is the apparent diameter of the entrance pupil, not the physical diameter of the lens, that determines the relative aperture.

LOL, what a rant. Name the camera system which didn't give you option of constant aperture lens?

I was wandering what is "sliding" aperture:)

I can sort of understand the annoyance of a variable aperture if you're metering externally and shooting manually. But even with TTLmatch needle metering it was little problem to adjust, and unless you're doing ambient light the metering is likely to change with the change in field anyway.

 

In any case I can't quite figure why a constant F4 lens would be better than a variable F2.8-4 lens. Insofar as a zoom lens can be constant aperture (light loss etc. being noted), I have yet to run into one on Nikons at least that does not become constant if you set the aperture at the long-end max. If you want it at F4 all the way, set it to F4. If you set your aperture at the long end you don't even have to look.

An excellent lens can have a variable maximum aperture, q.v., Sony 100-400/4.5-5.6 GM. However, companies have traditionally lavished their greatest attention on optics and build quality for constant aperture zooms, particularly f/2.8 zooms. Until recently, even constant f/4 zooms have received short shrift from Nikon and Canon.

 

Automatic exposure has rendered the issue of variable apertures moot, except for their long association with kit-quality. Any thread which discusses slow or variable lenses invariably brings out trolls who wouldn't buy anything less than a constant f/2.8. It's the bokeh, don't you know ;)

One can buy a lens like this for approx $50 or less:

"Vivitar Series 1 70-210mm f/3.5 macro telephoto zoom lens with Nikon AI mount"

If one does not mind manual focusing, perhaps that's a good low priced alternative to the variable aperture zooms.

I used a lens like that back in the 1980's in a Canon FD mount with a Canon F1N with very satisfactory results.

One can buy a lens like this for approx $50 or less:

"Vivitar Series 1 70-210mm f/3.5 macro telephoto zoom lens with Nikon AI mount"

If one does not mind manual focusing, perhaps that's a good low priced alternative to the variable aperture zooms.

I used a lens like that back in the 1980's in a Canon FD mount with a Canon F1N with very satisfactory results.

 

Back in the day when I was an FD shooter, one of the few variable focal length lenses I used was the Vivitar Series 1 35-85 f/2.8 Varifocal.

 

Vivitar did NOT advertise this as a zoom lens, as the focus point does change quite dramatically as the lens is zoomed. None the less, it's one of the few f/2.8 variable focal length lenses available for the FD system, and covers three useful focal lengths(35mm, 50mm, 85mm). On the few occasions I dared do weddings, I usually cut my second shooter loose with that lens on my T70 along with a roll of Portra 400NC and a Canon 299T during the reception.

 

I know it pales in comparison to modern offerings, but it was quite well regarded in the 1980s and still brought decent money(esp. for a 3rd party FD mount lens) in the mid-2000s when I bought mine. For that matter, now that I'm a full blown Nikon guy I've wanted to pick an N/AI mount one, but the few that I'v watched or even nibbled on have brought more than I wanted to pay(and not too far off from what an older 35-70 f/2.8D AF-Nikkor would cost). Most of the Series 1 Vivitars were universally well regarded in their day, and although they're not as well built as the best manual focus Nikkors or Canon L lenses, they're a definite cut above the build quality of Sigma ARTs. Even in their day, they were a BIG step up in build quality from Nikon Series E lenses and the "consumer' oriented Canons.

How about a bayonet to threaded adapter for filters that would have the bayonet mounted to the threaded lens? Anyone want to start a business?

How about a bayonet to threaded adapter for filters that would have the bayonet mounted to the threaded lens? Anyone want to start a business?

 

I paid a decent amount of money for a Bay 50 to 55mm threaded. I'm not anxious to go the other way :)