Sony alpha 100 (1 Viewer)

O

Old Pirate

Youthful Grandfather

• Mar 1, 2007

• #21

I've had this camera for about 6 months and like it fine.

I've tried one of the kit lenses and the old Minolta 70-210 F4 (Beercan) for birding with fair results. Actually fairly decent pictures, but never long enough.

Yesterday I ordered a new Tamron 200-500 so I hope to get over that length envy in due time. From pictures I've seen here and the few I played with at the camera shop I look forward to using this new lens.

This lens and in body stabilization seem to make a good combo. Even the Canon and Nikon dealer where I bought the lens said the Sony in body system would give you two to three fstop equivalences as far as keeping still.

 

mmdnje

Jose

• Mar 1, 2007

• #22

Old Pirate:
I've thinking of getting this lens myself. My problem is that I'm still having a great time digiscoping, so it always feel I'm too far away with dSLR. Please let us know how it works for you; post some pictures. Jose

 

O

Old Pirate

Youthful Grandfather

• Mar 1, 2007

• #23

Will do...however...

Many of my pictures will be from the swamps and creeks, and tidal areas of eastern NC so birds will share time with fins, fur, and reptiles.

However, maybe I'll be able to find something of interest with that hoss of a lens.

 

carp-angler

Active member

• Mar 9, 2007

• #24

I've got one and use my minolta lenses but have tried to use the 2x converter with it but it will not focus. Any one got any ideas why this happens???

 

DenisG

Well-known member

• Mar 10, 2007

• #25

carp-angler said:

I've got one and use my minolta lenses but have tried to use the 2x converter with it but it will not focus. Any one got any ideas why this happens???

Click to expand...

Could be dependant on the lenses you are using it with Steve. A 2x telecon reduces light by approx 2 stops so if you have, say, an f5.6 lens it now becomes an effective f11 lens. The Alpha is only at its best at max f5.6/f6.3 'ish although in good light they can work at f8!!. That's why most telecon manuf's will say that auto focus is only possible with lenses f2.8 or wider. What lenses were you trying it with?. Switch to manual focus and all should be well.

Avoid using these with zoom lenses by the way. A 1.4x you can sometimes get away with but 2x will almost surely dissapoint.

Denis.

 

mmdnje

Jose

• Mar 10, 2007

• #26

HI everyone. Denis G: could you elaborate a little more on the following statement: "The Alpha is only at its best at max f5.6/f6.3 'ish although in good light they can work at f8!!. "
I am routinely using f9-f11 and today I tried up to F22, and the camera did fine. I'm just learning about dSLR so please forgive if this is a dumb question. The attach pic was shot at f22. Jose

 

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DenisG

Well-known member

• Mar 11, 2007

• #27

mmdnje said:

HI everyone. Denis G: could you elaborate a little more on the following statement: "The Alpha is only at its best at max f5.6/f6.3 'ish although in good light they can work at f8!!. "
I am routinely using f9-f11 and today I tried up to F22, and the camera did fine. I'm just learning about dSLR so please forgive if this is a dumb question. The attach pic was shot at f22. Jose

Click to expand...

Jose, that reference only refers to when autofocus will work, nothing to do with general aperture settings. Whether you use f1.2 or f64 with a normal lens and the wide open aperture is f1 to f8, no additions like telecons, autofocus should always perform well, subject to available light. This is because the lens is always wide open for focus. However, once "wide open" becomes f6.3-f8'ish then the lens struggles and focusing becomes almost impossible.

A typical case would be if you had say an f5.6 400mm lens it should work reasonably well although low light may hinder this. Now, if you add a 2x telecon you lose two stops worth of light. Therefore your f5.6 lens is now really f11, two stops greater than normal, ie: f5.6 > f8 > f11. Hope you understand that. Autofocus generally won't work when "wide open" becomes f8, often less. Again, if you puchased (or borrowed) a 500mm f11 catadioptic mirror lens you would have to use it in manual mode. Almost all cameras with autofocus are like this.

If the previous poster who asked the question was using a typical f4/f5.6 zoom lens and added the 2x telecon, autofocus would certainly not work, hense his problem.

Personally, I often use f32 on my macro lenses without problem but they are f2.8 and focus at that setting, only adjusting to f32 when the shutter button is fully depressed.

Hope you follow that|=)|

Denis.