Sunday, 21 February 2016

More lens experiments.

Having seen a bit of chat on a Sony E-mount forum about problems with "shutter shock" on the A7r, I thought I would do a few test shots with different lenses, shutter speeds and apertures. There are 8 images and I have taken a central crop from each one at 3000x2000 pixels for a closer inspection. All lenses are close to their minimum focus distance.

The first lens is a Makinon 135mm

f2.8. 1/3200s


f2.8, 1/3200s

f8, 1/125s

f8, 1/125s

Next is a Pentax 50mm
f1.4, 1/800s

f1.4, 1/800s

f8, 1/60s

f8, 1/60s


Next is the Sony FE 28-70mm using deliberately long shutter speeds on a tripod (gorillapod resting on carpet)

f5.6, 1/20s

f5.6, 1/20s

f5.6, 1/10s

f5.6, 1/10s

 Finally, a Cosina 200mm - again with long exposures on the gorillapod

f4, 1/25s

f4, 1/25s

f6.3, 1/8s

f6.3, 1/8s

There is no doubt that the shutter does clunk a bit, but there is little evidence of camera movement in these images, maybe a little in the 200mm 1/8s shot mounted on an imperfect tripod. The image is slightly worse than the f4, 1/25s photo.

In theory the worst shutter speed range is 1/30 to 1/100s - but here, the 1/60s image at f8 on the Pentax 50mm is spectacularly the best image.

My general impression is that you have to be very picky to find a much fault with shutter shock and even then you have to try fairly hard to make it significant.







Monday, 15 February 2016

More old glass - 500 year old windows at "the Vyne"

First an apology - I was playing with the high ISO noise reduction setting on my Sony the other day and forgot to set my picture quality back to RAW+JPG so these images were all shot in high quality jpeg only.

We had heard about the restored Tudor stained glass exhibit at The Vyne, and as it is only a little over half an hour's drive from home thought we would visit on Sunday.

The Vyne is a Tudor house near Basingstoke in Hampshire, which has been owned by the National Trust since 1959.  It was built in the first half of the 1500s and substantially modified in the early 1700s.

The stained glass windows now in The Vyne chapel are part of a series made for the owners of The Vyne between 1515 and 1542, probably originally for the Holy Ghost Chapel in Basingstoke. They were moved during the English Civil War, concealed in chests and hidden in the lake to avoid destruction by the Puritans and then installed at The Vyne. The fine detail is applied as a paint and then fired into the glass.  This paint was becoming eroded and starting to peel, so a major programme of work was recently carried out by the National Trust, restoring the windows to their former glory and preserving them for the future. They are regarded as the finest stained glass of the period in the UK.

Here are 6 photographs depicting the main panels

Left panel upper
Hi res version



Left panel lower
Hi res version

Centre panel upper
Hi res version

Centre panel lower
Hi res version

Right panel upper
Hi res version

Right panel lower
Hi res version

These photos were all shot whilst trying to balance noise, depth of field and shutter speed in a low light environment so I used iso400, mainly f6.3 and shutter speeds varied between 1/13s and 1/300s.

Although the restored stained glass is a major feature, The Vyne is a beautiful National Trust property and well worth a visit - here a a few more views of the house and grounds



Higher res version





Higher res version



Friday, 5 February 2016

Old lenses - a cheap alternative?

This was originally a facebook post in Bluedog photography
I posted a couple of pictures yesterday taken with a lens that I found in box stored in my loft (roof space) and Danielle said she would like to hear a bit more. I got interested in “legacy” lenses when I found that my Pentax DSLRs could use most lenses for Pentax SLRs since the year dot and that for manual (M) mode and manual focussing, lenses were available very cheaply. In PK mount I have a 28mm f2.8, a 135mm f2.8, a 200mm f4 and a 400mm f5.6, made for 35mm film SLRs bought for a total of about AU$300.These lenses are not necessarily light but they are compact compared to modern autofocus lenses. I had some fun with these, going out for a day with a single fixed focal length lens etc. and when I bought a new camera the Sony A7 was an obvious choice as I can work with all my existing lenses.

In the first photo, there is a Pentax K5 with the brilliant Tamron 17-50mm f2.8, the tiny Sony A7 with my old Russian Jupiter8 50mm f2 and a Pentax K7 with the kit 18-55mm f3.5-5.6 . The APS-C Pentax with the Tamron weighs in at a whopping 1300g and the full frame Sony with the Jupiter weighs just 660g. The lenses are the 135 f2.8, the kit 28-70 for the Sony and the 28mm f2.8. Notice the difference in thickness between the Leica M39-NEX adaptor on the Jupiter lens and the PK-NEX adaptor on the 28mm. Rangefinder cameras such as the Leica have no mirror and the lens mount is much closer to the film than in an SLR so the Jupiter has a thin adaptor. The Jupiter is a Russian copy of a pre-war Zeiss Sonnar for a Leica thread – mine is 40 or so years old.
In a normal DSLR, the mount is too far from the sensor to fit rangefinder lenses but legacy SLR glass can work. The Sony is mirrorless and the viewfinder is electronic, meaning that the sensor is very close behind the bayonet mount and with the right adaptor ANY lens can be fitted and used in A or M mode with manual focussing. I have been working in A mode, focussing by hand is enough extra work.
It is recommended to focus at full aperture with minimum DoF and then stop down but this isn't always easy when the aperture ring is on the lens and costs time (my Pentax lenses will stop down automatically with the shutter but I need to stop down manually to set the exposure). On the Sony there is a focus magnifier which I have programmed to button C1 next to the shutter. I am trying to focus at full aperture with magnification and stop down by watching the shutter speed change in the viewfinder. Additionally “focus peaking” indicates points of sharp focus in the Sony viewfinder with a coloured light. With short lenses, the hyperfocal distance markings on the focus ring can be used to preset the focus, saving time.
The second photo is from the Jupiter-8 on the Sony at f2.8 1/60s and iso200 – The bokeh has an interesting vintage look, personal taste.

I really enjoy using these old lenses and I will refine my shooting procedure with time. I spent so much time focussing on this dog he kept moving and I had to do it again. I want to be able to shoot portraits quickly with the Jupiter lens. 

Not every camera can use the old lenses, but if yours can and you are prepared to experiment there are some fine lenses out there (or in your loft) and relatively cheap fun to be had.