A new lens or a new camera?

[DavieR]

I haven't been around for a long while but I'm still enjoying using A900 and the images it produces.

I have a Sigma 100-300mm f4 but need a longer lens now and then. I'm considering the 500mm f8 mirror lens or adding a 2x converter. But then I read David's excellent review of the A55 and, given the 1.5x crop factor, I start thinking this might be a better all round option (a lighter camera for hillwalking, brighter viewfinder/actual depth of field visible for macro work for starters). I have no experience of APS-C sensors.

I want 5000px wide images at an equivalent of 500mm full-frame. Which of these options would give me the best quality image?

1. A900 plus 500mm f8 mirror.
2. A900 plus Sigma 100-300mm and 2x extender.
3. A55 plus Sigma 100-300mm (gives 450mm and 4900px image, so a bit of cropping/interpolation needed. Uses the centre of the image circle though).

My thoughts are that cost wise, the 2x extender is the cheapest option but probably the worst quality option. A new 500mm mirror costs a bit more than the A55 (with UK VAT back offer) and weighs more, but which will give me the highest quality image, I don't know.

Thanks.

[David Kilpatrick]

I have no doubt you will get better results either from the A580 or A55 used with the Sigma. You can still add a 1.4X or 2X teleconverter later on for extreme reach.

The f/stop advantage is probably as much as 2 or even 3 times. First, needing no converter means you still get f/4 and a very sharp f/5.6. The 2X converter only gives you f/8 and the 500mm mirror a fixed f/8 with less depth of field than a normal f/8 because of the design. Second, the A55 or A580 have an ISO quality advantage over the 900, meaning you can work at ISO 1000 to 1600 instead of (say) ISO 640-ish. This combination could transform wildlife shots for you.

The A55 would also give you a very bright finder image in dark Scottish winter conditions (it does not make snow look very nice though!) and its 10fps, 6fps, 'almost silent' operation might also help. The A580 would give you a more traditional viewfinder experience.

Hillwalking, I think the A55 with its GPS would be great. It's accurate enough most of the time to put you on the correct side of whatever path you left to shoot a photo but the height above sea level figure seems to be way out on many shots.

David

[DavieR]

I have no doubt you will get better results either from the A580 or A55 used with the Sigma.

Thanks David, I'm rather pleased you think that as the A55 has some other advantages for me.

I'm no wildlife photographer but the ISO advantage might means that I can use higher shutter speeds on my tripod mounted landscapes (I'm struggling to get sharp images at 300mm @ around 1sec - 1/60th). Is the A55 less prone to vibration from the shutter?

I see the EVF as a distinct advantage for my insect macros (so perhaps I am a wildlife photographer!). I've been using a Sony 100mm Macro on a set of Minolta Auto Bellows (to get between 2-3x magnification) with diffused flash and chasing hover-flies around my garden. The A900 viewfinder is still fairly bright but depth of field, such as it it, is difficult to judge. I also bolt my A900 on to a set of Nikon bellows and use a enlarging lens for around 4-5x mag. I think the A55 would be great there too. I guess there is some apparent gain in magnification with the smaller sensor, but I'm not too sure of the maths there.

I wonder if I would find the GPS useful? I'm still to embrace GPS navigation of any kind - I love compass work and maps! I find that I can remember where I took images as long as I know the day I took them (easy) and have a map - even years after I took them. Granted, it might be fun and as faculties fail ...

Thanks again.

David

[gio67]

why oh why did i read this thread,
David you have me wavering now i was quite happy with my 700 until i read it.
the photographers disease I need a cure the thing is the cures are so short lived,
a great rundown on the cameras nonetheless,thanks

[Scooterman]

I haven't been around for a long while but I'm still enjoying using A900 and the images it produces.

I have a Sigma 100-300mm f4 but need a longer lens now and then. I'm considering the 500mm f8 mirror lens or adding a 2x converter. But then I read David's excellent review of the A55 and, given the 1.5x crop factor, I start thinking this might be a better all round option (a lighter camera for hillwalking, brighter viewfinder/actual depth of field visible for macro work for starters). I have no experience of APS-C sensors.

I want 5000px wide images at an equivalent of 500mm full-frame. Which of these options would give me the best quality image?

1. A900 plus 500mm f8 mirror.
2. A900 plus Sigma 100-300mm and 2x extender.
3. A55 plus Sigma 100-300mm (gives 450mm and 4900px image, so a bit of cropping/interpolation needed. Uses the centre of the image circle though).

My thoughts are that cost wise, the 2x extender is the cheapest option but probably the worst quality option. A new 500mm mirror costs a bit more than the A55 (with UK VAT back offer) and weighs more, but which will give me the highest quality image, I don't know.

Thanks.

If you can try both the A-55 and the A-580.
I did, and ended up with the A-580, I use the Sigma 100-300 mm f4 also the Tamron 200-500mm for my wildlife shots and of course the Sony 100mm macro lens for insects and flowers.
I also have the A-550 but that is not being used as much now, my A-850 and A-700 are no longer with me, I can do all I want with the copped sensors.
Everything is a personal preference and for me this setup I have works.
But you could buy both the 55 and the 580.
Regards
Richard

[Simmondsphotography]

Unlike Richard, I still have both my A900 and A700 and I also use the 200-500 Tamron and a 70-400 Sony G. The A700 is a virtually bomb proof built compared to many of the newer Sony's, but with a slower sensor. In my view the APS-C sensor provides a better image than the A900 cropped down to the same image size with the same lenses but if you can fill the frame with the A900, just about nothing other than medium format can touch it in my view.

As mainly a wildlife photographer I know how difficult it is to fill the A900 frame sometimes whereas the same lens on the A700 can fill it nicely and will then produce a cleaner image. I imagine the same would apply to the A580 but without the robust build quality. If this is not important to you, then either the A580 or A55 if you happen to like EVF's (I don't!) should do an excellent job for you.

[Scooterman]

I quite agree, my only reason for letting the A-700 go was my age? Hearing the high focus confirm sound - I though mine was faulty but it was my hearing that was!
Also the focus points are not as clear for my old eyes; The A-580 is fine.
The 850 is a fine camera ideal for landscapes etc, but my days of walking miles is over after spinal surgery, also I don’t require the “water proofing” on a camera these days I just don’t stay out in the wet.
Regards
Richard

[DavieR]

Re GPS. DK wrote in his A-55 review "The camera didn't just save time in keywording and captioning images, GPS gave me named locations I could not find on any tourist map." This is a good point, so perhaps I'l become a GPS convert yet!

Richard wrote "If you can try both the A-55 and the A-580." I think the A55's EVF is an important factor for me. I can see my macro photography benefiting from being able to see the actual depth of field on a bright screen. I guess a A-580 would e nice too, but somewhere a line must be drawn!

Dave. Thanks also for your comments confirming DKs's thoughts on APS-C v. cropped A-900 image quality.

I'll do some more reading but I think my mind is made up. Jessops seem to be offering the best deal at the moment, but they are not as cheap as they were a short while ago.

EDIT: This morning, Cameraworld seem to offer the best deal at £629.99