Digital zoom versus GT-1 lens

[Blow-in]

A demand for a '35 or 40 mm equivalent' lens seems to be a popular from GRD III & IV users. It's been suggested in other threads that it might be worth trying the optical zoom at either 1.2x (roughly 35 mm equivalent) or 1.4x (roughly 40 mm equivalent) so I thought I'd try a little experiment by comparing a GRD with the GT-1 lens (1.43x) against the GRD IV using the 1.4x digital zoom.

I set both cameras to ISO100 and F2.8 with the white balance on cloudy and the EV on zero. I used a tripod and all images are jpegs resized to 1024 width for the website.

The first shot is the GRD with GT-1

The second is the GRD IV set to 3:2 (same as the GRD) which means that the auto resize facility is not available (auto resize helps maintain the image quality by maintaining the actual capture rather than upsizing to what ever is set...I think!).

The third shot is the GRD IV set to 4:3 with the zoom image at normal.

The last is the GRD IV set to 4:3 with the auto resize option selected.

Looking at the images 'blown-up' I do think the auto resize option provides a better IQ than zoom image normal. I think there is a bit more depth to the GRD image but that may be down to the sensor...interested in your views of course and if it ever stops raining I may try some digital zoom in the great outdoors.

Richard

 

[v_roma]

Interesting comparison. I'm not familiar with the auto-resize zoom option. That said, the first picture looks slightly sharper to me but it may be my imagination or may be due to the loss of some resolution due to cropping (i.e., digital zoom) in the other pictures. At the sizes posted, it doesn't seem like a huge difference, though, which was a little surprising. Ultimately, I just wish Ricoh would release a 40mm GRD There were also some rumors at some point about a GRD zoom but I haven't heard anything else so they may just be rumors.

 

[Blow-in]

Interesting comparison. I'm not familiar with the auto-resize zoom option. That said, the first picture looks slightly sharper to me but it may be my imagination or may be due to the loss of some resolution due to cropping (i.e., digital zoom) in the other pictures. At the sizes posted, it doesn't seem like a huge difference, though, which was a little surprising. Ultimately, I just wish Ricoh would release a 40mm GRD There were also some rumors at some point about a GRD zoom but I haven't heard anything else so they may just be rumors.

Thanks for your comments & interest. We are all normally a bit 'sniffy' about digital zoom but perhaps we should think again? My understanding is that when you normally use a digital zoom the camera saves the image at whatever image size setting that you have - so if it is 10M it will still save a 10M image despite having zoomed and this can cause pixelation (a bit like enlarging). With auto resize the IV saves the image without enlarging...so at x1.2 you get a 8M image and at x1.4 you get a 5M image - if someone can provide a better explanation I should be so grateful! On the IV if you have the zoom set to normal you see x1.2 or x1.4 on the display as you zoom but with auto resize (only in 4:3) you see 8M or 5M etc instead. Ricoh claim that this (auto resize) helps maintain IQ and I think they are right.

I love the GT-1 lens on the GRD despite the famous flare problems which means you may need to crop the image (the GRD doesn't allow 1:1 capture which nearly always eliminates the flare) but it is a big and heavy piece of glass. I think the IV using auto resize and x1.4 (actually 5M) comes quite close...where I expect it is very close in IQ is at x1.2 (ie 8M and roughly 35mm equivalent) and I've just returned with 2 shots posted below taken at this setting (with auto resize) as it seems to have stopped raining (for now). I suppose the real proof would be to post crops or to take prints.

I've re-thought my settings as a result and now have the zoom button set to digital zoom and the exposure compensation set on FN1 (FN2 switches between AF & Snap and with the IV I leave the snap on auto as this seems to work really well).

I expect to be asked to leave the forum as result of using digital zoom!

Richard

 

[Blow-in]

At last a dry and partially sunny day in the Highlands. The ground is very wet so the air clarity is poorer than normal but I thought I'd try some digital zoom shots of a distant view with the GRD IV using the auto resize function.

1 press captures a 8 megapixel image at roughly 34 mm equivalent focal length

2 press is 5 megapixels at roughly 40 mm

3 press is 3 megapixels at roughly 50 mm

I just took 4 shots trying not to move the camera and without changing any settings other than the zoom. They are jpegs with no PP other than resizing to 1024 width to post. Adjusting the EV for each shot would have improved the quality.

You could say isn't this just cropping in camera and why not take all your shots @ 28mm then crop as part of PP? My only response really is that you may select a different framing point when taking the shot if you see the crop in advance. Whether the images using digital zoom are usable depends upon what you intend to do with them...obviously if you intend to make a large print you will see a loss in IQ. You could also say that if you want a zoom lens you should buy a camera that has a 'proper' optical zoom. I wouldn't argue with that point other than to say I quite like the focal length at '1 press'....you are using the 'sweet' part of the lens and if, like me, you use the GV-2 for framing, what you see in the GV-2 is very close to what you get....worth at try?

Richard

 

[uKrris]

Richard,

Thanks for the time and effort put into this post. Very interesting comparison. The ' Highlands ' photos are especially nice. Something new to try.