Are Kelda Lenses Acceptable?

[abrogard]

These Kelda lenses I find on ebay seem too good to be true. Are they?

https://www.ebay.com.au/itm/500mm-Su...kAAOSwcYxZi9Qn


My longest lens is 250mm on a canon eos 400d and it falls just a bit short on a frequent shot i get of some small birds (wrens) that frequent some bushes I can get within about 3 or 4 metres of but no closer. Outside the kitchen window, really.

So I'd like something a bit longer. 300, 400?

And Kelda seem to be offering all kinds of stuff. I did a google for reviews and saw some not necessarily matching these recent Kelda offerings that didn't speak too well of them.

Nor did they speak too badly.

I'd be very interested in getting the opinions of this community.

: )

[Donald]

I've never heard of Kelda, which of itself says something.

Personally, I'd steer well clear, based on nothing other than the fact that is you cannot/don't get a 500mm fixed length of any quality for AU $189.99. If you did, the world would beating a path to your door.

The advert/selling line doesn't tell you what aperture it is. If they can't even get that text correct, what chances has the lens got of being any good!

[William W]

The lens is made by Changchun Kaili Optronics Co., Ltd.

[LINK]

This company makes quite a few lenses.

This particular lens is a Manual Focus and Manual Aperture Lens: meaning you have to (physically) focus the lens using the Focus Turret (on the lens) and you have to (physically) set the aperture using the Aperture Ring (on the lens).

The Lens does not have Image Stabilization.

It being a Manual Aperture Lens also means that of you use TTL Metering (through the lens) you will need to use “stop down metering” method to assess the exposure you want to use.

Its maximum aperture is F/6.3.

The lens is a T-Mount, which means that is adaptable to many camera bodies via a “T-Mount to xxx Mount” (xxx meaning your camera mount): if buying a T-Mount lens, it is important to also buy the adapter so it can mount to your camera.

The (lack of) modern refinements (the main being auto focus, auto aperture, IS) and making one lens in a T-Mount to fit many cameras with an adapter means the company can restrict costs.

That stated, there is a general implication/assumption that mass produced T-Mount Lenses will also suffer in the areas of: Build; Manufacturing Tolerances; Parts Quality and thus a resultant relative poor Image Quality. However this may not be prohibitive to purchase – it depends on the user’s requirements.

Without Image Stabilization, I expect that you will NEED a good Tripod and Head, maybe, in some circumstances you could get away with a Monopod. Especially if your camera is APS-C Format.

***

I have several (third party) Manual Focus and Manual Aperture lenses which I use on my DSLRs and Mirrorless cameras; these lenses of mine, are used with the camera hand held. The longest FL = 105mm and all mine are fast or extremely fast (very large maximum aperture), which means (amongst other things) that my viewfinder is very bright, allowing ease of manual focus. None of these lenses were bought because of (low) price, but rather because of their special features and none were made by Changchun Kaili Optronics Co., Ltd.

Manual Focusing and setting Manual Aperture and using Stop Down Metering is not a burden for me as these are techniques I originally learned when I began my training.

***

I would not buy this lens and I would caution that you consider the advantages of cost versus the disadvantages of (cumbersome) usage.

For the specific tasks that you outlined -

"My longest lens is 250mm on a canon eos 400d and it falls just a bit short on a frequent shot i get of some small birds (wrens) that frequent some bushes I can get within about 3 or 4 metres of but no closer. . . I'd like something a bit longer. 300, 400?"

I suggest that you get as close as you can and make the best quality image file you can, not exceeding ISO800, with your existing 250mm Lens and crop that file in Post Production.

WW

[Manfred M]

There is an old saying that runs "it it looks too good to be true, it probably is".

As others have stated, I would view this lens with extreme caution. It is a 100% manual lens and manually focusing a long, slow lens is challenging on a modern camera that are designed for autofocus lenses. You will also have to shoot on manual as there are no electronic connections to your camera body. Be prepared for a lot of shots that are not focused or well exposed.

Modern lenses cost a lot of money because they have advanced optical and electronic components. No one can build and sell a quality lens for that kind of money.

[rpcrowe]

Lenses like this have been around for a long time... I purchased a lens of this type for my first SLR Film camera; probably around 1970. It is NOT a "telephoto" lens but, rather a "long-focus" lens. The difference is that the distance from the optical center of a telephoto lens to the film/sensor plane is less than the focal length of the lens while a long-focus lens is physically at least as long as the focal length when focused at infinity and usually extends quite a ways longer when focused at closer distances. As such, this type of 500mm long focus lens is very long and, IMO, quite unwieldy. It is of course, manual focus and manual exposure. That combined with the small maximum aperture, makes a lens quite difficult to use on subjects that move at all. Even with still subjects, the use of this type of lens can be quite chancy because there is no stabilization resulting in requiring a shutter speed f/stop - ISO combination that can be exceedingly high! Additionally, although my lens was reasonably sharp, its contrast was so low that the images were often close to unusable.

If you are looking for a Canon compatible lens of 400mm that is completely decent quality with both auto focus and auto exposure capability at a very low price, I suggest that you look for a used Tokina ATX 400mm f/5.6 lens with a Canon mount.

This is an excellent lens in all respects. I used one for years until I replaced it with a Canon 400mm f/5.6L lens which is one of the best BIF lenses available. IMO. the Tokina ATX lens was the equal of the Canon 400mm L lens in image quality but, although the ATX had decent AF quality, it was not quite a match in auto focus speed for the Canon lens for BIF.

The really nice thing about the Tokina ATX is that if you find one, the price should be well under $150 USD (and often in the $100 price range). However, they are difficult to find since the Tokina ATX was produced for a very short time before being replaced by the Tokina 80-400mm ATX which is a decent lens but, in a higher price range.

There is a Tokina 400mmm f/5.6 SD lens available which does not "quite" match the quality of the ATX.

Another decent low priced ($100-150 USD) telephoto lens is the Sigma 400mm f/5.6 but, IMO it is not quite up to the quality of the Tokina ATX.

However either the Tokina SD or Sigma, and definitely the Tokina ATX would beat the pants off the lens you were considering in all respects...

Now, if you still want a lens of the type you were considering, eBay has a plethora of these lenses used (some with the Vivitar label) at around $50 USD or below...

[William W]

One of the considerations for photographing moving Subjects, (even if they're birds in a tree, they're almost always moving), is the limitations of the ISO of the Digital Camera. I alluded to this in Post #3.

Explanation:

I know the EOS 400D and it is a good camera, yet as with any tool, it has its unique set of limits. One of these limits is its high ISO capacity. Obviously, we all have different considerations and mine would like to limit the ISO when using an EOS 400D to maximum ISO800; moreover, ISO400 provides a noticeably better file than ISO800, in most situations.

This is important when considering the dependence/relationship Shutter Speed has on/with ISO and Aperture.

Let’s assume a practical scenario where we are photographing birds in a tree. Let’s assume we have an EF-S 55 to 250 F/4~5.6 lens on an EOS 400D and it is a mildly overcast day and/or the birds are in open shade, in the tree. This certainly would describe a ‘typical’ situation. Such a scenario would lead to EV ≈ 12 as the measure for the correct exposure for the birds.

So, for EV = 12, we’re pulling 1/400s @ F/5.6 @ ISO400. I reckon that’s a suitable Tv for birds in a tree, but we might not want to use the lens wide open at F/5.6, so we might consider 1/200s @ F/8 @ ISO400, alternatively, we might choose 1/400s @ F/8 @ ISO800.

The key point about the above (probable) practical example is to show that with an F/5.6 lens; an EOS 400D and birds in a tree in open shade or on an overcast day, we will be approaching the limits and we will likely need to make some choices which will either risk capturing Subject Motion Blur or an increase in noise. (Aside – I’d almost always opt for more noise).

Now let’s substitute the 55 to 250 for a Manual Focus and Manual Aperture, non-IS 500mm F/6.3 lens. (Arguably the lens in question in most real-world situations would be considered ‘wide open’ when at F/8 and for the ease this commentary I shall assume that).

So, for our birds in the tree in open shade we start at: 1/400s @ F/8 @ ISO800. The point being there is 1 stop less wiggle room to stop the lens down for (almost certainly) attaining better Image Quality.

Additionally, (as mentioned above by others) we have to allow time to Manually Focus the lens (at F/6.3) and then (quickly) Manually Stop the lens down to F/8 to pull the shot – all this whilst keeping the camera steady if Hand Holding.

The topic of Hand Holding brings is another matter to the fore – we now have moved from (assumed) an 250mm Image Stabilized Lens to a 500mm non-IS lens. Enter the issue of Camera Movement Blur.

Whilst we might require 1/400s to arrest the Subject Motion Blur of birds in a tree, arguably we will require faster than 1/1000s to arrest Camera Motion Blur with a 500mm lens on and APS-C Camera, when it is Hand Held.

Returning to our birds in the tree, with our 500mm lens hand held we might require something like: 1/1600s @ F/8 @ ISO 3200 – which is becoming next to impossible with a 400D.

WW

(Aside - The actual Tv required to arrest Camera Motion Blur is mainly dependent on the person and technique – and that within most individual's capacity will vary from day to day, anyway.

We can refer to the 1/FL Rule of Thumb, which personally I don’t prefer, but rather I prefer to do few field tests on me and use those results as “my” Rule of Thumb.

Also, any Rule of Thumb, for Camera Movement Blur, is just that a rule of thumb, a guide – NOT a definitive Rule.

I know from my tests that I can pull at least a 60% keeper rate using a 400mm non-IS lens, hand held, on APS-C camera at Tv = 1/800s. Additionally moving to Tv = 1/1600s I know I am in the high 90% keeper range which is a big jump for only one stop of Shutter Speed.)

[rpcrowe]

I have a Sony 70-350mm f/4.5-6.3 E OSS lens. Although I wish that his lens had a faster aperture, I am quite happy shooting with this lens on a Sony APSC camera. I was able to get an f/6.3 at 1/3200 second hand-held exposure for this shot of a perched raptor using ISO 320 with the lens maxed out to 350mm (525mm equivalent). I had the shutter speed that high because I expected the bird to take off (which he did not while I was there).



Granted this was in the bright Southern California winter sun but, I could easily increase the ISO if the bird was in the shade. I have no hesitation using ISO 1280 or even higher with the little Sony...

Alternately, I could slow down the shutter speed since the bird was not moving. The combination of OSS and In body image stabilization will provide crisp images of non moving subjects at considerably slower shutter speeds.