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標題: Advice on 18mm - 250mm zoom lens [打印本頁]

作者: Bonkinasia 時間: 2008-9-25 17:47 標題: Advice on 18mm - 250mm zoom lens

I am user of Canon 450D camera with 18mm - 55mm and 55mm - 250mm.
These lenses are good enough for me to cover most of the range (distance)
of my photography needs, however I found it very troublesome and bulky to
carry along during my travelling to other countries.  Considering replacing
with a single 18mm - 250 mm zoom.

Now I have found 2 other manufactuers making zoom lenses in the range
of 18mm to 250mm. Just wonder which model are better in term of producing
better photo quality.

1.  Tamron Lenses - 18mm - 250mm zoom (with IS)
2.  Sigma Lenses - 18mm - 200mm zoom (with IS)
(both are F:3.5 -  F:6.3 zoom lenses and can be mounted for my Cannon 450D DSR).

The other more expensive one is  the Nikon 18mm - 200mm, I doubt it has cannon mounted bracket.

Can users of these lenses advise, thanks.

[ 本帖最後由 Bonkinasia 於 2008-9-25 09:51 編輯 ]

作者: khadafy 時間: 2008-9-27 01:19

死馬...........不需要考慮！

作者: WURTH 時間: 2008-9-27 15:08

我用緊籘籠A18, 18-250mm Nikon F-mount.
我發覺vignetting(光學暈影) 好緊要下.
其次個zoom 鏡好鬆, 鏡頭向下就會自然滑到250mm.

睇下張相 250mm eqv 400mm f/6.3 iso 100.

[ 本帖最後由 WURTH 於 2008-9-27 15:11 編輯 ]

作者: WURTH 時間: 2008-9-27 15:22

Canon 好似有支新鏡EF-S18-200mm F3.5-5.6 IS
http://cweb.canon.jp/newsrelease/2008-08/pr-efs18200.html

作者: mike925 時間: 2008-9-29 00:44

提示: 作者被禁止或刪除內容自動屏蔽

作者: Bonkinasia 時間: 2008-9-29 10:27

Actual the best lens for travelling use should be 17mm to 85mm - this lenses of Canon
Brand is rather expensive. When I got my 450D camera it comes with 18mm to 55mm & 55mm
to 250mm zoom lenses, these 2 zoom lenses are at half the price of one  17mm-85mm zoom.

So no point to go back buying this 17-85mm lenses again and for the half the price I can
obtain another non-Canon Brand 18mm to 200 or 250mm zooms. The other alternatives is
to get Canon Lenses Extenders.  Canon has 1.4X and 2X Lenses Extenders at affordable
prices.  These extenders will reduce the lights by one f-stop and 2-stop respectively.

[ 本帖最後由 Bonkinasia 於 2008-9-30 07:13 編輯 ]

作者: peninsula 時間: 2008-9-29 20:32

引用:

原帖由 Bonkinasia 於 2008-9-29 10:27 發表
Actual the best lens for travelling use should be 17mm to 85mm - this lenses od Canon ...

Good point!

作者: khadafy 時間: 2008-9-30 02:46

引用:

原帖由 Bonkinasia 於 2008-9-29 10:27 發表
Actual the best lens for travelling use should be 17mm to 85mm - this lenses od Canon
Brand is rather expensive. When I got my 450D camera it comes with 18mm to 55mm & 55mm
to 250mm zoom lenses, t ...

Bonkinasia兄都講得幾 o岩...
17-85我都用過,出相都幾靚,又有防震,價錢又唔貴,實是一個好的選擇...
至於果D高倍數Zoom鏡...我都未有發現有那一支是好的...
至於死馬就..........

作者: Bonkinasia 時間: 2008-9-30 15:04

引用:

原帖由 khadafy 於 2008-9-29 18:46 發表

Bonkinasia兄都講得幾 o岩...
17-85我都用過,出相都幾靚,又有防震,價錢又唔貴,實是一個好的選擇...
至於果D高倍數Zoom鏡...我都未有發現有那一支是好的...
至於死馬就..........

Thanks for all the advices. I had thought of getting a 17mm-85mm Canon Zoom but this lenses is
rather expensive. Perhaps I would re-consider and get 10mm-22mm zoom lenses from Canon. This will
cover a wider angles and completed my set of canon lenses from 10mm to 250mm except that these
3 lenses added up are too bulky, not convenient for travelling use. The prices for 10mm-22mm is now
very cheaper than 17mm-85mm. I am very calculative when come to purchasing of my hobblies items.

Perhaps, I will also add in another 2x Lenses Extenders, to be brought together with my 18mm-55mm
zoom lenses for my future travelling....................................

I have noted that even the lenses wth Image Stabiliser (IS) over a long distance of more than
200mm there still have some 'shaking effect', and have to reduce your aperture opening by 2 F-stop.
Hence tele-lenses of 200mm and above needs to use camera-stand and unless you carry stand along
during travelling, these long distance tele-lenses are not very convenient.

Can someone advise me the differnce between the film ASA and the ISO?
Is film ASA 100 = Digital ISO 200?

作者: Bonkinasia 時間: 2008-9-30 15:31

Actual if you want more stable and better quality, you should consider single range tele-lenses. These lenses should be better and are more stable than zoom lenses (for 200mm and above). It will be able to offer bigger aperture opening (f:1:4 or f:1.8) but at a higher price.

Canon lenses prices (HK$)
http://www.canon.com.hk/en/Consumer/Product/default.aspx?cat_id=25&series_id=31

Tamron lenses
http://www.tamron.com.hk/index.htm
http://www.tamron.com.hk/Tamroncamera/product/p-2-a18.htm

Sigma lenses
http://www.sigma.com.hk/lens/digital/index.htm

[ 本帖最後由 Bonkinasia 於 2008-9-30 15:19 編輯 ]

作者: Bonkinasia 時間: 2008-10-5 14:21 標題: Canon lenses will not autofocus if with the extender, the f-stop is over f 5.6.

[quote]原帖由 Bonkinasia 於 2008-9-30 07:31 發表

I refer to my earlier discussion on zoom lenses manufactured by non-Canon factory.
These 2 lenses Sigma Zoom 18mm to 200mm, F/3.5 – 6.3 & Tamron zoom 18mm to 250mm, F3.5 – 63.
Both are not suitable for Canon DSLR (450D) camera.

The Lenses Extenders are good for high speed lenses and Tele-lenses (F/2.8) not suitable for lenses greater than F/3.5.

Let me explained:

Most makers of DSLRs make 1.4X and 2X tele-Extenders for their lenses but they may not work on all of their lenses. Like Kenko and Sigma, they make these for certain cameras. A few companies make a 1.7X and 2.5 TE.  These lenses do exactly what you are thinking but at a cost of f-stops which can be helped by increasing your ISO, else you have to use camera tripod all the ways.

Canon lenses will not autofocus if with the extender, the f-stop is over f 5.6.

A 1.4X loses 1 stop.
A 2x loses 2 stops.
A 1,7X loses 1 2/3 (or about) stops.

As an illustration:

A 70-200mm f4L with a 1.4X ( f4 plus 1 stop = f5.6) and I will still have auto focusing.  With the same lens and a 2x extender (f4 plus 2 stops = f8) there is no autofocusing but I can still focus manually.

A  70-200mm f2.8L with a 1.4X ( f2.8 plus one stop = f4) no problem. With a 2X  (f2.8 plus 2 stops= f5.6) and it will still autofocus.

This does vary with lenses so you should read the directions from both the lens manufacturer and the tele-Extenders manufacturer.

A Canon 100mm f2.8 Macro lens will not accept a Canon Extender.  It may (I don't know) accept a Sigma or Kenko. Some other companys make an equivalent lens and will accept the extender.

You just simply have to asked the user who have tried them. Salesman sometimes do not really tell you the truth, only half truth in fact. The 2 equivalent zoom lenses I mentioned can be used for my Canon 450D DSLR except that when you zoom to a distance exceeding F/5.6 the Canon Autofocus function will cease its function.  Lucky I have yet to make purchases of these zoom lenses and Tlele-Extenders. (I am a user for my OLD SLR camera before, but the construction and its functions really differs.)

Well, I am off for photos taking now..........................................bye.

[ 本帖最後由 Bonkinasia 於 2008-10-5 06:38 編輯 ]

作者: Bonkinasia 時間: 2008-10-5 23:52 標題: Testing Photos

Attached 3 photos taken by 450D...

作者: Bonkinasia 時間: 2008-10-6 18:26 標題: 3 shot of butterflies.............

Just share with all of you another 3 shots of butterflies photos........................

Photos deleted - high resolution slow down the display...................

[ 本帖最後由 Bonkinasia 於 2008-10-8 08:28 編輯 ]

作者: peninsula 時間: 2008-10-6 21:53

引用:

原帖由 Bonkinasia 於 2008-10-5 23:52 發表
Attached 3 photos taken by 450D...

Quite OK!

作者: Bonkinasia 時間: 2008-10-8 01:12

引用:

原帖由 Bonkinasia 於 2008-10-5 06:21 發表
[quote]原帖由 Bonkinasia 於 2008-9-30 07:31 發表

I refer to my earlier discussion on zoom lenses manufactured by non-Canon factory.
These 2 lenses ...

Canon lenses will not autofocus if with the zoom lenses, the f-stop is over f 5.6.

The longest (or upper) distance f-stop should not be over f/5.6.

All the zoom lenses manufacture by other brands with f-stop f/3.5 - 6.2 are not suitable
for use with Canon DSLR 450D, I think it will not work with other Canon model as well.

For tele-lenses, it is wiser to buy with f/2.8 and NOT f/3.5, so that with the 2X Lenses Extenders it will still allow the autofocus function of Canon Camera to be functioning.

I hope these information is useful for those who want to upgrade to non-Canon lenses.

[ 本帖最後由 Bonkinasia 於 2008-10-8 08:30 編輯 ]

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